Mild weather: Long-lasting, or a temporary reprieve?

After a month of the coldest December weather in many years, the Carolinas finally are getting a break as we head into the New Years holiday.

A weak low pressure system is crossing the area today, bringing clouds and a few sprinkles, but skies will clear later Thursday night and usher in a very nice New Years Eve. Fans heading to Friday's Meineke Car Care Bowl at Bank of America Stadium will have sunshine, temperatures in the upper 50s, and -- judging from the tepid ticket sales -- plenty of room to spread out.

Nice weather will continue through New Years Eve, and relatively mild conditions are expected to continue through next week.

That raises the question: Is this the long-awaited breakdown of the pattern that brought us cold, sleet and snow in December? Will our La Nina winter -- mild and dry -- finally get under way?

Or is this just a temporary reprieve?

Based on what long-range forecasters are saying, it's the latter. The cold and stormy weather is returning, they say.

The Greenland block -- a strong high pressure system that brings cold and storms into the eastern United States and into Europe -- is making a comeback. The consensus seems to be a wintry pattern will return around Jan. 10, and the eastern United States will face another extended period of nasty conditions.

So whatever happened to La Nina?

I asked two experts, and they agree ... the North Atlantic Oscillation (NAO) and Arctic Oscillation (AO) have been far too strong for La Nina. The pattern of the jet stream, sending cold air and storms on a roller-coaster ride southward from the Arctic into the U.S. and Europe, has cut off the predicted west-to-east pattern of milder conditions that we'd expected.

It shows, once again, that long-range predictions are tricky. When we're told to expect an El Nino (cold and chilly) or La Nina (mild and dry) winter, those Pacific Ocean conditions are only part of the story. The NAO and AO have a big role in what happens, along with some other factors.

To be fair, some of the long-range winter forecasts (I'll give Accu-Weather's Joe Bastardi credit for this) said there'd be occasional episodes of arctic blasts intruding on La Nina. But December was a lot more than an "episode." It was nearly the whole month.

So if all this is true, we'll get about 10 to 12 days of seasonal weather here in the Carolinas before we head back into the deep freeze.

One cautionary note ... forecasters are only 1 for 2 on recent predictions of cold weather. They were 100 percent correct about December, but some meteorologists had called for a cold weather outbreak in late October. That didn't happen.

However, with solar energy very low now, a return to cold weather doesn't seem too far-fetched.

A white Christmas, or not?

After all the talk last week about the chances of Charlotte getting its first white Christmas since 1947, now we're left with a debate.

Was it a white Christmas, or not?

Rain changed to snow about 7 p.m., and reliable sources tell me the ground was coated with snow by midnight. I was dreaming of sugar plums by that time.

Snowfall was even heavier to the north and of Charlotte, where there were several inches on the ground by midnight.

However, the real answer isn't quite to easy.

"Officially, it will not go into the record books as a white Christmas," says John Tomko, a meteorologist at the National Weather Service office in Greer, S.C. Tomko is responsible for keep weather data for the western Carolinas, and he says that according to the rules, Christmas 2010 was not white.

"The snow depth for the day is measured at 12 UTZ (12 noon Universal time, or 7 a.m. in Charlotte," Tomko says.

At 7 a.m. Christmas Day, the sun was still shining through a layer of broken clouds. The precipitation didn't arrive until at least eight hours later.

So in the record books, Charlotte's last white Christmas was in 1947. Who knows how long it will be before we have another opportunity?

Tomko acknowledges that some people don't care about the weather rulebook.

"I'm sure a lot of people had a dusting of snow in the evening," he says. "To them, it was a white Christmas. And I'm not going to argue with them. They'll probably remember it as a white Christmas.

"But according to the rules, it was not."

Tomko says Charlotte had 2 inches on the ground at 7 a.m. Sunday, the official measuring time for Dec. 26. But between 3 and 4 inches actually fell from the storm.

Snow drama ... behind the scenes

If you've followed the news stories I've written, and those written on the TV websites in Charlotte, you can tell that there's been an awful lot of back-and-forth adjustments the past few days regarding the Christmas storm system.

All along, we kept saying it would be the final 24 hours before we really had a good idea where it would snow, and how much would fall.

The latest run of the Global (GFS) model has taken us back into Snow Central again.

It shows a more potent storm system, with a lot more precipitation than the computer had indicated in its runs Thursday night and early Friday morning. And while there are still question marks about the temperature -- it'll be close to freezing Saturday during much of the precipitation -- the chances for a significant snowfall are climbing again.

I just saw a GFS panel that shows potential snowfall accumulations by the end of the weekend, and it shows a solid 2-4 inches in our area, with 5 inches or more in a swath along the U.S. 1 corridor -- Raleigh-Durham, Sanford and maybe even Fayetteville.

That panel shows an inch of snow as far down as Atlanta, in fact.

Predicting this storm has been a real pain.

Initially, the European model predicted a monster storm developing off the Carolinas coast. The GFS showed a moisture-weak system moving across the Gulf of Mexico, keeping its moisture far south of Charlotte. Then the European began weakening the system, and it looked like the chances of a white Christmas in Charlotte were dimming.

Now, at noon on Christmas Eve, there's this latest GFS run.

Stay tuned ... this could be interesting.

Latest forecasts ... whiter than ever

The latest computer model runs -- from midday -- are in, and they continue to paint a snowy picture in the Charlotte area and elsewhere across the Carolinas for the second half of Christmas Day.

The newest trend is for a low pressure system to strengthen very rapidly off the Carolinas coast and deliver a blizzard from Virginia northward.

Under this scenario, we wouldn't escape in the Charlotte area.

Before we go any farther, let's introduce a new wrinkle -- the timing of the storm. If it should arrive fairly late Saturday, temperatures might have climbed above freezing. That means the first few hours of precipitation could fall as rain, before a changeover to snow in the evening. And that would limit the accumulations somewhat.

The Global (GFS) and Canadian computer models' latest runs continue to show limited precipitation for Charlotte, which means light snow accumulations (a few inches, at most).

The latest run of the European computer model shows up to a foot of snow falling in Charlotte and even more in the Raleigh-Durham area. North of there, they could be measuring snow in feet, and they'd have howling winds of 40 mph and stronger to deal with.

All of this is 72 or more hours away, and you know how this winter forecasting business goes. A lot can change between now and then.

But the computer models, which are based on the science of meteorology (including weather history), seem to paint a picture of a major snowstorm affecting the eastern United States.

Let me thank my brother Michael, who's much more the scientist than I am, for his help in this. But here's a very preliminary look at what could happen this weekend:

In Charlotte: Christmas Eve would be dry, and it would still be dry when you awake Christmas morning. Snow would move into the area sometime between midday and mid-afternoon, and it would continue into Sunday morning. Accumulations could be heavy.

In Raleigh: Precipitation might begin as rain early Saturday afternoon, but it would change quickly to snow. The latest European model shows more than a foot of snow in the Triangle area. Much of eastern North Carolina would be affected.

Columbia: It'll be a rain-snow mix, but temperatures would be cold enough Saturday night and early Sunday for some snow accumulations.

Myrtle Beach: The picture is that of a rainstorm, with temperatures near freezing and strong winds.

Atlanta: Some snow, but it's too early to tell how much might accumulate. The rain-snow line could be close to the Atlanta area.

More to come. Stay tuned.

Snow? Yes ... but how much?

All right -- let's all join Bing Crosby and Danny Kaye, and sing along ...

I'm dreaming of a white Christmas.......

The National Weather Service's computer models -- all three of them -- are singing the song today. There is now unanimous agreement among the computers, and most meteorologists, that snow is coming to the Charlotte area on Christmas weekend.

The big questions:

1. Will it actually fall on Christmas Day, or will it arrive early Dec. 26?

2. How much?

Yesterday, the GFS (Global) computer model was predicting the major storm system in the West would move across the Charlotte area, bringing us rain. The other two models forecast a track along the Gulf coast, which would mean snow.

But the GFS model is singing the "White Christmas" song today, so let's move on to the other questions.

Forecasters say one of the computer models, the European, is leaning toward a slower-moving storm, which might not bring snow to the Charlotte area until late Saturday night or early Sunday. The Global model predicts snow will start Christmas morning, while the third model forecasts snow in the afternoon.

Why is the arrival time important?

For historic reasons, I guess. The last major snowfall in Charlotte on Christmas Day was in 1947, when 5 inches fell. There has been a trace of snow -- which means flurries or sleet pellets -- a few times since then.

As for the amount, meteorologist Pat Moore of the National Weather Service was brave enough to make a rough and very early guess -- 3 to 5 inches. However, Moore notes, if the slower European model is correct, snowfall totals could be doubled.

Naturally, this is exciting news for anyone who wants a white Christmas and loves snow.

But this storm will have a nasty impact for travelers. The snow will cover Arkansas and Tennessee on Christmas Eve, and when the storm departs the Carolinas on Sunday and moves north, it will spread heavy snow up the East Coast.

If you're planning to travel back toward Charlotte from New York, New Jersey, Pennsylvania, Maryland or Virginia on Sunday or Monday, you'd better allow yourself an extra day -- just in case.

"If this forecast works out, it could be an event that will be talked about the rest of our lives," the Weather Service's Moore says.

Christmas snow? Let's be cautious

Yes, the National Weather Service forecast is mentioning that word for Christmas Day.

But will it really snow in Charlotte for the holiday? History indicates we should be very cautious before planning a sleigh ride down Providence Road on Saturday evening.

The computer models used for weather forecasting agree that a strong storm system hammering California today will cross the Rockies, dive toward the Gulf Coast, and then move up the East Coast by Saturday and Sunday.

There seems little argument that parts of the East Coast could get a major winter storm late Saturday and into Sunday. If you're planning a Christmas trip to Washington, Baltimore, Philadelphia, New York or even farther north, then snow is a good chance.

Roads could be in bad shape later Saturday and Sunday, and the flight schedules could be a mess both days.

Depending on the track of the storm, inland parts of the Middle Atlantic and New England could get hammered. If the storm hugs the coast, then heavy snow will fall in places like Frederick and Hagerstown in Maryland; the Harrisburg and Scranton-Wilkes Barre areas of Pennsylvania; and upstate New York.

But what about the Carolinas? Well, here is your lineup of computer model predictions. Take your choice:

GEM: This is the snow-lovers' computer model. It predicts the storm system will cross northern Florida, reach the coast near Charleston, and curve north. That would mean a significant snowstorm for the Charlotte region, starting as rain late Friday night but changing to snow by Christmas morning. Under this scenario, the snow-rain dividing line could be well into South Carolina.

ECMWF (European): This computer model takes the storm along the Gulf Coast. That would mean temperatures in Charlotte will be cold enough for snow, but most of the precipitation would stay to the south. We might see snow, but not enough for any significant accumulations.

GFS: Meet the Grinch, oh you fans of a white Christmas. The GFS predicts the storm's center will cross the Charlotte area. That means rain, except for snow in the mountains. In fact, the rain could be rather heavy, in this scenario.

Doug Outlaw, of the National Weather Service office in Greer, S.C., says forecasters there are leaning toward the GEM forecast, for snow in the Charlotte area. For now, they believe the best chance of accumulating snow would be northwest of Interstate 85.

The forecasters at private companies like Accu-Weather and the Weather Channel are following the GFS. They predict rain for Charlotte.

"It's simply too early to know for sure," Outlaw said. "In a day or two, I think we'll start seeing the models come more in line with one another. That's when we'll get a better idea of what actually will happen."

Either way, Outlaw says, the storm will be a newsmaker as it rolls up the East Coast after leaving the Carolinas.

"Some places up there will certainly get their white Christmas," he said.

In case you're wondering, the last serious white Christmas in Charlotte was in 1947, which was so long ago that even I hadn't been born yet. That year, 5.8 inches of snow fell in the Queen City. There also was a 4-inch snowfall in 1880 and 0.2 inches in 1909.

A trace -- we're talking about brief flurries -- was recorded several times, including 2007, 1998 and 1993.

Last year produced a major rainstorm in Charlotte, but there was a devastating ice storm in the N.C. mountains. Up to a half-inch of ice accumulated in Watauga and neighboring counties, knocking out power to tens of thousands of customers for several days.

Freezing rain might be on horizon

The worst thing about the latest outbreak of cold weather (I say "worst" for those who don't like these conditions) is that it apparently won't leave soon.

And this time, it could come with some added complications, in the form of frozen precipitation for the Charlotte area.

The immediate concern in the Charlotte area is cold weather and strong winds, but meteorologists are watching a system which could cross the region late Wednesday or Thursday. The last few times a storm system moved into our area, temperatures moderated above freezing, and the precipitation fell as rain.

This time, it will be a closer call.

Temperatures are expected to be below freezing when the precipitation arrives Wednesday night or early Thursday morning. For now, forecasters think this will be a weak low pressure system, which means light precipitation.

But it likely will start as snow or sleet, then change over to freezing rain for a while before turning to rain later Thursday morning. National Weather Service meteorologists have been referring to the system as a "nuisance" storm, which means sleet and icing problems are not expected to be big.

Thursday's system could be more of a headache along the Interstate 40 corridor (that means you, Hickory and Statesville!), where temperatures might not get above freezing until later in the day. That would give more time for ice and sleet to accumulate.

Yet another system could develop Sunday. Brad Panovich, chief meteorologist at WCNC-TV, the Observer's news partner, says that storm could produce a swath of snow as it moves from the Gulf of Mexico to the East Coast. Areas to the northwest of the low pressure system's center would get the snow.

It's far too early to get a good reading on the track of the low, but stay tuned.

Computer models paint a cold picture for the Charlotte area until Christmas. Some forecasts indicate we won't see 50 degrees for the next 12 to 14 day, and there could be another freezing rain threat around Christmas Eve.

If you're one of those people who's been yelling for cold weather, so you'd get in the holiday spirit, I hope you're happy.

Weekend storm, then more cold

I've heard people focus on the forecast for warmer temperatures this weekend, but they might be missing the bigger story of what's ahead for the Charlotte region.

Yes, it looks as if we'll get a three-day moderating trend from the brutal cold that has covered the Carolinas this week. High temperatures Friday will climb into the upper 40s, and with 55-degree readings Saturday and Sunday, it'll seem almost balmy.

But a big storm system will be crossing the East this weekend, and another surge of very cold air will follow the storm. It looks as if next week's temperatures will be every bit as cold as this week.

This week's weather is the coldest air in the Charlotte area since an arctic outbreak that stretched from mid January to early February in 2009. It dropped to 9 degrees on Jan. 17 that year, and there were several morning lows in the sub-20-degree range.

The big storm system this weekend appears as if it will follow a track north of Charlotte. That will keep any chance of snow to our north, but it means places in the Ohio Valley, the Middle Atlantic, and the Northeast could get walloped by heavy snow and wind. We'll get a better idea about that in the next few days.

Here in the Carolinas, heavy rain could fall, especially late Saturday and early Sunday. Once again ... we'll have a better idea on the timing and amount of precipitation in a few days.

Then behind the system, cold air will pour in again. High temperatures next Monday will remain in the 30s, and more of the same seems likely for next Tuesday.

No let-up in the cold pattern can be seen for the next two weeks, actually.

Those Big Winter Storms: A little more than a week ago, I wrote about computer-generated forecasts (from the GFS model) that indicated a chance of a major winter storm in the Carolinas for Dec. 8 and then again around Dec. 13.

As I wrote at the time, the long-range computer models are notoriously unreliable, and that is being borne out. Tomorrow is Dec. 8, and it'll be clear but very cold. The Dec. 13 storm (that's next Monday) seems headed for our area a day or two early -- as a rain-maker, not a producer of freezing rain or snow.

I've fallen victim to looking at long-range forecasts myself, and this is another reminder that we can't get too excited about what a computer says will happen two weeks down the road.

Is Charlotte too cold for ACC title game, bowl game?

Well, the first ACC football championship game in Charlotte didn't exactly get Chamber of Commerce weather.

Sleet pellets and even a few snow flurries fell around daybreak and again Saturday afternoon in the Charlotte area, and while the precipitation likely will be cold rain -- not the frozen stuff -- for tonight's kickoff, it certainly won't be attractive weather.

I realize some people believe football should be played in Green Bay-esque weather, but I suspect the majority would prefer temperatures at least in the 50s for a championship game, and for the bowl game played annually in Charlotte.

All this begs the question (which has been raised many times before): Is Charlotte too far north for an outdoor football championship game? And is it too far north for a bowl game?

We'll dismiss the bowl game question immediately.

When the NCAA can sanction bowl games in New York City (the new Pinstripe Bowl) and Washington (the EagleBank Bowl) -- and, for that matter, the bowl game in Boise -- it's silly to question holding such a game in Charlotte.

Our weather is roughly similar to several other places that host bowl games, including Nashville and Memphis. And besides, the worst snow I ever saw at a bowl game happened once in the early 1980s, when North Carolina played Texas in the Sun Bowl in El Paso. I think it was in 1982. It was a whiteout.

But the ACC title game is another matter, because it was played the first five years at Florida sites, where sleet and snow almost certainly won't be a problem.

I went back and checked Charlotte's weather for the last seven years on the first Saturday in December, and I found -- perhaps not surprisingly -- that it's wildly inconsistent. The evidence:

2009 (Dec. 5): High of 47, low of 28, with .05 of an inch of rain. That's pretty crummy weather.

2008 (Dec. 6): 42 and 31 degrees, with a trace of rain. Once again, bad weather.

2007 (Dec. 1): 62 and 47 degrees. Fantastic!

2006 (Dec. 2): 59 and 36 degrees. Once again, fantastic.

2005 (Dec. 3): 50 and 27 degrees, with .05 of an inch of rain. Mediocre, but good enough.

2004 (Dec. 4): 35 and 33 degrees, with .21 of an inch of precipitation, some of it as freezing rain. Uhhh ... I don't think so!

2003 (Dec. 6): 82 and 66 degrees. That set a record for the latest 80-degree day in Charlotte history. Obviously, few people would have complained.

So over the past seven years, the weather was mediocre or better four times, and not good on the other three years.

Supporters of the effort to bring the ACC championship game to Charlotte note that the average temperature in Jacksonville, site of several of the league's title games, is only a few degrees warmer than here. That's correct, and I recall bad weather in Florida at least once.

The average high and temperatures at this time of year in Charlotte are 57 and 37, which is fine for football.

So let's hope the weather is better next year, and chances are it will be. Besides, as long as fans show up, the ACC will be happy, no matter what the weather.

That 4-letter word ... snow

You can kiss the mild weather good-bye for a while, as a real outbreak of winter is taking shape over the Carolinas and much of the eastern United States.

Among the highlights (or lowlights, if you're not a winter weather fan):

1. A chance of snow mixing with rain for a few hours after midnight Saturday in the Charlotte area.

2. Very cold temperatures next week in the region, with daytime highs struggling to get out of the low 40s some days.

3. The lurking possibility of a winter storm sometime around Dec. 13.

The weather pattern in the Northern Hemisphere is undergoing a major shift, because strong high pressure has established itself over Greenland. That is blocking the typical west-to-east movement of weather systems, and instead, we're getting exaggerated dips in the jet stream.

One of those dips is over the eastern United States. Another is over the British Isles. Heavy snow has been falling the past few days over parts of England and Scotland, with up to 10 inches accumulating in some London suburbs. It's unheard-of weather for this time of year in that part of the world.

Closer to home, the cold weather we've experienced the past 24 hours is merely a tuneup for what's ahead.

It dropped to 23 degrees Thursday morning at Charlotte/Douglas International Airport, the coldest since a 22-degree reading March 7. But it could fall to near 20 degrees next week.

A low pressure system will dive southward Saturday, crossing North Carolina and bringing rain and snow showers. Meteorologists -- the National Weather Service, The Weather Channel and Accu-Weather -- agree that the precipitation will fall as rain over South Carolina and snow in the N.C. mountains.

It looks like rain showers will move into the Charlotte area Saturday evening, and they could mix with snow for a few hours early Sunday. Some forecasters think places like Winston-Salem, Greensboro and Raleigh could get a coating of snow from this system.

If you're going to the ACC championship football game Saturday evening, look for cloudy skies, temperatures in the low 40s, and a small chance of a rain shower.

The weekend low will usher in the really cold air. A northwest flow will establish itself, and while that type of pattern produces dry weather in the Charlotte region, it will be very, very chilly.

You can expect daytime highs in the low 40s and morning lows in the lower 20s for the first three or four days next week -- and that's despite full sunshine during the daytime hours.

The computer models continue to indicate the chance of a big winter storm around Dec. 13 (a week from Monday). I mentioned this earlier in the week, and the long-range forecasts continue to show such a system developing. The computer models haven't changed much for a couple days, putting Charlotte in an area that could get cold rain or frozen precipitation.

By the way ... the other computer model-predicted wintry storm was supposed to have developed Dec. 8. That's Wednesday, and it looks as if we'll have absolutely dry conditions, although it will be plenty cold enough for snow.

I mention that busted Dec. 8 forecast to remind all of us that Dec. 13 could wind up being dry, too.

Bastardi's White Christmas. I know some of you weather geeks are not big fans of Accu-Weather's Joe Bastardi, who specializes in long-range forecasts. But it's interesting to note that Bastardi is predicting that about half the country will have a white Christmas. That compares, he says, to an average of 25 to 30 percent of the United States having snow on Dec. 25.

His map of snow on Christmas includes parts of North Carolina, with the line drawn quite close to the Interstate 85 corridor.

I'll go with the averages. Snowfall is recorded in Charlotte, on average, about once every 25 or 30 years.

Tornado watch extended until 4 a.m., more areas included

A tornado watch has been extended for the Charlotte region until 4 a.m. Wednesday. The weather system that could produce tornadoes swept into the region slower than expected.

The watch includes all counties in the Charlotte region except Anson, Stanly and Richmond. Basically, the watch covers the area from Union County westward.

Once we get past the stormy weather, chilly temperatures are coming.

Much of the explanation about this system is in my blog post from earlier today (see below).

We'll keep tabs on developments throughout the evening.

Tough night could be ahead

Conditions appear primed for an outbreak of severe weather this evening and overnight in the Carolinas and southern Virginia.

Meteorologists locally and at the Storm Prediction Center in Norman, Okla., are predicting severe thunderstorms and possible tornadoes in that area. On top of that, flooding is likely in the mountains, and some flooding already was taking place early Tuesday afternoon.

The scenario has developed pretty much the way we outlined it yesterday, with strong low pressure moving eastward across the South, a warm front pushing northward through the Charlotte area, and a cold front advancing from the west.

Charlotte moved into the warm and unstable area about 11 a.m. The temperature at Charlotte/Douglas International Airport rose from 54 degrees at 9 a.m. to 65 degrees two hours later. Dewpoint temperatures soared from the upper 30s early this morning to near 60 degrees.

The temperature actually might approach 70 degrees in Charlotte this evening.

In contrast, Hickory, which remains in the cool and more stable air, was at 45 degrees at 1 p.m. Heavy rain is falling in the cool area, however, but temperatures probably won't ever climb out of the 50s in the foothills, so that area is expected to escape the severe weather. Flooding will be more of a concern there.

A flash flood warning was issued at midday for the Hendersonville area, with flooding reported near the airport. More flood warnings are likely later today.

But the severe weather situation probably will develop in the Charlotte area sometime this evening.

By early Tuesday afternoon, a tornado watch was in effect for much of Georgia, and you can expect that watch pushed into the Carolinas in a few hours. Tornadoes and severe thunderstorms were pounding western Georgia.

Jonathan Garner, a meteorologist at the Storm Prediction Center in Oklahoma, said the corridor of damaging winds this evening probably will stretch from the Piedmont to the coastal plain in the Carolinas. He also said strong tornadoes are a possibility.

Once the cold front crosses the area, sometime early Wednesday, the stormy weather will come to an abrupt end. And temperatures will take an abrupt tumble, too. Look for temperatures to fall from near 70 at midnight to the lower 50s by daybreak, and they won't climb much Wednesday.

Frozen Precipitation? Yesterday, I wrote about the GFS computer models indicating a chance of wintry storms around Dec. 8 and Dec. 13. I plan to follow that prediction every day until those dates arrive -- so we can get an idea of how the computer-generated forecasts often change dramatically.

But so far, there's nothing new to report. A strong storm system is still forecast to cross the area Dec. 8, and another storm system is predicted to move up the Carolinas coast five days later. In both cases, especially the Dec. 13 storm, temperatures could be cold enough to present some problems.

We'll keep an eye on this.

By the way ... one reader reminded me yesterday that some weather followers refer to the GFS as Good For ****. Officially, it's an acronym for Global Forecasting System and is among several models used by the National Weather Service.

Trouble late Tuesday ... and beyond

Another round of stormy weather is headed for the Carolinas later Tuesday, and the computers hint at more trouble -- possibly of the frozen variety -- late next week and about two weeks from now.

Some rapid and major changes in our weather will take place over the next 24 hours.

A flash flood watch already is in effect for Tuesday and Tuesday night for Burke, Caldwell, McDowell, Rutherford, Watauga and Wilkes counties in the Charlotte region. Additional watches and warnings are likely Tuesday.

Today, we're locked in a chilly pattern, governed by high pressure off the East Coast. But the seeds of change are visible. The cloud cover that thickened overnight is a telltale sign of the moisture surging into the Carolinas from the Gulf of Mexico.

By later today, low pressure will move eastward from the Arkansas-Texas area. Rain gradually will spread into the Carolinas, falling mostly in the mountains initially but reaching the foothills and Piedmont by later this afternoon.

It will be a chilly rain at first, with temperatures staying in the 40s today and dewpoint readings also in the 40s.

But a warm front on the east side of the low pressure system will move northward Tuesday, crossing the Charlotte area sometime in the morning. That will push our temperatures into the 60s, and the dewpoint temperatures will follow suit.

The Carolinas will be in the warm, unstable southeast side of the low pressure system by Tuesday afternoon and night, and that's where severe weather takes place.

Chris Horne, of the National Weather Service's office in Greer, S.C., says strong thunderstorms and heavy rain are forecast across the Carolinas, with the most likely area for severe weather being in the Piedmont.

"Some degree of thunderstorm wind damage threat -- perhaps even a tornado -- should exist into the night," Horne said.

These likely will be those sneaky severe storms -- the kind we experience in the Southeast during the winter. They move extremely fast, sometimes at 50 mph, and often have little or no lightning to herald their arrival.

And looking ahead? This part of the discussion is based on some GFS computer model projections for Dec. 8-9 and again Dec. 13. The GFS is one of several computer models used by meteorologists for long-range forecasts.

First, an important caveat ... long-range computer model forecasts often don't pan out. The science of meteorology has a tough enough time predicting 24 or 48 hours ahead. Forecasts such as these -- 192 to 264 hours in advance -- are iffy.

But the computers show a pattern of low pressure systems forming over the Southwest and moving across the Southeast and up the East Coast. This is exactly the pattern predicted by a number of long-range forecasters for the winter.

The big questions are: 1. Which path will the storms follow? 2. How much cold air will be in place in the Carolinas?

The storm path is important. If the Charlotte region remains on the north and west side of the storm's center, we're more likely to see cold rain or frozen precipitation. The GFS model has been waffling on the storm expected to affect our area Dec. 8-9, predicting a chance of frozen precipitation one time, then making it a rainy forecast the next. These models are updated a couple times each day.

However, the Dec. 13 storm system has been predicted consistently to remain east of the Charlotte area, putting us at a risk of something frozen.

I mention these GFS forecasts not to sound an alert about an upcoming ice storm. I think the computer models will change a bunch of times between now and then. In fact, the storm might never develop.

But I introduce the topic now, because we'll be dealing with it a lot this winter. Let's see how these long-range forecasts fare.

Attention, holiday shoppers. It's getting colder!

Timing can be everything in weather.

The folks who stood in line outside stores early this morning for those Black Friday specials caught a break. A strong cold front didn't cross the Charlotte area until about 7 a.m., several hours after the stores opened.

By that time, shoppers were inside. If the front had been earlier, the people in line would've gotten a drenching, as the front was accompanied by a band of heavy showers.

The early shoppers caught another break. Temperatures were near 65 degrees at 4 a.m., but the front dropped those readings 10 degrees in an hour, and we can look for the thermometer to keep falling during the day.

The heaviest of the rain has moved to the east, but we can expect a few showers until late afternoon. Meanwhile, temperatures probably will stay in the mid 50s for a few more hours but will fall into the upper 40s by late afternoon.

So if you have shopping plans later today, take an umbrella and a jacket.

And if you're heading out to a high school football playoff game tonight, count on a cold night, with a northwest breeze that will be strong enough to make conditions seem even chillier.

This cold front is a serious character. Nashville was basking in 70-degree weather at 5 p.m. Thursday. Nine hours later, at 2 a.m., it was 35 degrees, with light snow falling.

We won't see snow in the Carolinas today, but temperatures will be in the lower 30s Saturday morning and in the upper 20s Sunday morning.

After a brief warm-up Tuesday, another strong front is forecast to move through the area, bringing even colder air. Despite sunshine, our high temperatures next Thursday and Friday might not get out of the upper 40s.

By the way, a deep storm system over southern Canada and the colder air will produce the first significant lake-effect snow outbreak of the season in the Great Lakes. A west-northwest wind off lakes Superior, Michigan, Huron, Erie and Ontario will dump 1 to 2 feet of snow in parts of Michigan's Upper Peninsula (from Lake Superior); western lower Michigan (from Lake Michigan); southwest Ontario (from Lake Huron); the Buffalo area and northwest Pennsylvania (from Lake Erie); and upstate New York (from Lake Ontario).

Snow won't be a problem for the Panthers' game at the Cleveland Browns on Sunday. It will be cold (near 40 degrees) but sunny.

Thanksgiving travel could be iffy

Thanksgiving travelers have been lucky the last two or three years.

There has been little inclement weather in the East, and even the trip home for travelers has been good, for the most part. That's unusual, considering it's late November, a stormy time of year in much of the United States.

It looks like the good luck has run out.

A strong low pressure system and a couple of associated fronts will bring an assortment of bad weather to a number of popular travel destinations for Carolinas residents. That will include rainy weather and thunderstorms in the Southeast and up the East Coast, a blizzard in the Upper Midwest, possible severe weather late Wednesday in the lower Great Lakes, and utterly nasty wintry conditions in the Northwest.

Seattle and Portland, where snow rarely falls, could get some of the white stuff this week.

It's a fairly complex and fluid situation, which means the forecast likely will change a lot as we get closer to Thanksgiving and the days after, but anyone planning to travel this week should be aware that there could be a few bumps along the way.

And the bad weather will mean delays at the airports ... as if the TSA's new security measures aren't enough of a potential headache.

In the Carolinas, the bad weather probably will hold off until late Thursday and Friday.

By late Monday or early Tuesday, we should have a better idea on the timing of all this messy weather.

A winter of close calls?

Nearly every forecast I've seen for this winter paints roughly the same picture for the Carolinas and the rest of the Southeast:

1. Generally, a mild and fairly dry pattern (due to La Nina).
2. A storm track that takes most systems up the Appalachians and then through the Northeast either along the coast or slightly inland.
3. An occasional burst of arctic air southward -- with the boundary of the cold air stopping somewhere in the region of the Carolinas. Most of the time, it'll stall to the north of our region. But occasionally, it'll reach the Charlotte area.

That's why meteorologists like WCNC-TV's Brad Panovich have forecast a better-than-average chance of ice storms in our area this year. With both the cold air and the storm track nearby, we'll be on the edge between rain and frozen precipitation.

Incidentally, another common theme has been the idea that March could be a chilly and wet month in the East.

But I've seen another interesting aspect to this winter's forecast ... something to keep in mind in the weeks to come.

A couple of long-range forecasters have mentioned that they expect the computer models to produce several bogus predictions of cold air outbreaks in the East. This winter's pattern is set up for cold air and heavy precipitation in the Northwest, but some meteorologists think the computers will erroneously forecast the dip in the jet stream to progress into the East.

Most recently, I saw that comment from Dave Tolleris, who runs a private meteorological firm called wxrisk.com.

In early to mid October, some of the computer models began predicting an outbreak of cold and wet weather in the East. It never happened. We had a cold snap for a few days in the first weekend of November, but the latter half of October was mild. The prediction of stormy weather verified (remember the tornado outbreak on Oct. 25).

But the storm systems were working with mild temperatures.

Now it seems to have happened again. Some of the models earlier this week were predicting a surge of arctic air into the Southeast on Thanksgiving weekend. Now those forecasts are being scaled back.

We're looking for above-average temperatures early next week, with highs possibly reaching 70 degrees on one or two days. The cooldown will come late Thanksgiving Day, but the "arctic surge" now is predicted to be only slightly-below-normal temperatures. We're talking about highs in the middle 50s next Saturday and Sunday.

A Reminder, Folks: I saw a series of comments under one of my blog entries earlier this week, in which sometime questioned my credentials to write a weather blog.

Let me repeat what I wrote in my first blog entry ... I am not a meteorologist. I have been covering weather for almost a decade at The Observer, and I've attended a number of workshops and seminars. I've asked hundreds of questions of meteorologists, and when I don't have the answer to a question, I'll go back to them again.

This blog is not aimed at professional meteorologists. It's for people who are interested in weather, especially in the Carolinas. Basically, it's for weather geeks like myself.

I'll try to mix forecasts, weather stories, and some scientific discussion.

I am not writing this blog from a scientific standpoint. Instead, I'm trying to translate the science of meteorology into words that every-day people can understand. If I mention the North Atlantic Oscillation, I'll explain it -- rather than simply throwing the acronym NAO into this column. The same goes for a myriad other meteorological terms.

I hope that helps.

Atmosphere primed for trouble today

It won't take much to set off severe weather later Tuesday afternoon and early evening across the Charlotte region.

A low pressure system is moving northeast, on a track just west of the Appalachians. As the system moved into eastern Tennessee and Kentucky, it dragged a warm front northward across North Carolina. That put the Charlotte area in an area known as the "warm sector."

Being in the "warm sector" can mean trouble.

In today's case, it means strong winds are blowing from different directions at different levels of the atmosphere. That is known to meteorologists as shear. High levels of shear often are associated with severe thunderstorms and tornadoes.

"Shear is through the roof today," National Weather Service meteorologist Neil Dixon said early Tuesday afternoon.

But it takes another factor -- instability -- to combine with high levels of shear and create severe weather.

In the summer, daytime heating often causes air currents to rise in the atmosphere. There's your instability.

But there's not much daytime heating at this time of year, so the instability has to come from another source.

That source might be a cold front crossing the Southeast today. That front is expected to move across the Charlotte area early this evening and might produce small lines of showers and thunderstorms. If storms develop, they could become tornadic.

Severe storms and tornadoes at this time of year are especially dangerous because they can arrive with little warning.

"In this type of situation, it's possible to get a tornado without any lightning," Dixon said.

By later this evening, the cold front should have passed east of the Charlotte area. That will put an end to the severe weather threat.

My guess is the most likely place for severe weather will be in eastern North Carolina, where the instability levels probably will be higher than in the Charlotte area. But this is a situation worth watching today.

The Witch of November

I've been away from writing for about 10 days but didn't want to miss the opportunity to mark last week's 70th anniversary of one of the most deadly winter storms in U.S. history.

The Great Lakes and Upper Midwest frequently are recipients of vicious autumn storms, which are known in that area as the Witches of November.

Typically, a deep trough (low pressure system) over the Upper Midwest or in Canada causes a buckling in the jet stream, and strong storm systems ride that current of air. Frequently, these storms move inland off the West Coast, dive southward in the Great Plains, and then surge northeastward across the Midwest or Great Lakes.

As was the case with such a storm system Oct. 26 and 27, these low pressure systems can have amazingly low barometric pressures -- equal to those of Category 2 hurricanes. Normally, the result is a wind machine and sometimes a blizzard.

While the Oct. 26-27 storm set records for low barometric pressure, meteorologists usually point to the Armistice Day Storm of 1940 as the most memorable in weather history.

For some reason, many of these storms seem to form on Nov. 10 or 11, and the Armistice Day Storm was, of course, a Nov. 11 event.

It killed more than 150 people, including more than 60 sailors on ships that sank in Lake Michigan and dozens of duck hunters in Minnesota and Iowa.

The storm came with little warning, as the U.S. Weather Bureau of that time was still developing its forecasting methods. Temperatures were in the low 40s as the low pressure system swept into Iowa, Wisconsin and Minnesota, but those readings plummeted to single digits in some parts of Minnesota.

Stories of the time tell of duck hunters who were on small islands in the Mississippi River when the storm arrived. They tried to take shelter, but many drowned when the 50 mph sustained winds (with gusts around 80 mph) created waves of 4 and 5 feet on the river and inundated the hunting camps. Others died of exposure to the cold.

Nearly 17 inches of snow accumulated in Minneapolis-St. Paul, and drifts of up to 20 feet were reported in the region.

With much more sophisticated forecasting tools and better communication systems today, an Armistice Day Storm still could cause plenty of problems but almost certainly wouldn't leave such a death toll.

The Carolinas aren't immune to such a powerful cold-season storm system. A similar storm swept across the Southeast and the East Coast in March 1993, you might remember. That storm produced record snowfall in parts of Alabama, Georgia, Tennessee, the Carolinas, Virginia, Pennsylvania, West Virginia, Maryland and New York.

The immediate Charlotte area escaped with only a few inches of snow, but Carolinas mountain residents measured the snow in feet.

Autumn arrives ... at its worst

You know those beautiful crisp autumn days, when the color of the leaves contrasts against the clear blue sky?

Well, forget about it for a while.

We're facing two days of autumn at its worst, courtesy of a Carolinas specialty -- cold air damming.

And when that event ends, it'll be replaced by an invasion of the coldest air we've experienced since last spring.

After weeks in which it seemed as if daytime temperatures in the 70s and 80s would stay with us forever, some really chilly air is filtering into the Carolinas. Highs today will reach the 60s, thanks to sunshine.

But low pressure will form in the Gulf of Mexico later today and then move up the East Coast later Wednesday and Thursday. At the same time, high pressure over the Northeast will send a flow of chilly air into the Carolinas.

Cold air, being heavy, sinks. This cold air will pile up against the mountains, and clouds will form. High temperatures Wednesday and Thursday won't escape the 50s, and there'll be a chilly northeast breeze to make things worse. This situation is called cold air damming, because the cold air is dammed up against the mountains.

In such an event, sunshine and temperatures 10 to 15 degrees warmer often can be found on the western side of the mountains.

The low pressure system moving up the Carolinas coast won't be strong enough to produce much rain, and the Charlotte area won't get much more than 1/10 to 1/4 of an inch, mostly from noon Thursday to early Friday. But with the gloomy skies, it'll be rather ugly around here for a few days.

On Friday, a cold front will wash out the chilly, damp air. But it also will bring winter-like temperatures, with Saturday's highs only reaching the low to mid 50s. Morning lows Saturday probably will be around freezing, and that will put an end to the growing season for much of the area.

First frost almost on schedule

Temperatures in the mid to upper 30s, little or no wind, and clear skies are good ingredients for a light frost, and that's what the National Weather Service is predicting for the immediate Charlotte area Saturday morning.

A frost advisory, which means scattered light to moderate frost, is in effect for Mecklenburg, Union, Cabarrus, Rowan, Catawba, Lincoln, Cleveland and Gaston counties of North Carolina, and for Chester and York counties of South Carolina.

A freeze watch, meaning actual freezing temperatures, has been posted for Iredell, Alexander, Caldwell, Burke, McDowell and Rutherford counties.

The chance of freezing temperatures in Iredell County is probably to the north of Interstate 40, so the southern part of the county is more likely to get frost than a freeze.

No advisories have been posted for Stanly County in North Carolina or for Lancaster County in South Carolina, but scattered frost is possible there, too -- especially in the Lancaster County "panhandle."

First, a little class on frost.

Frost is caused when water vapor in the air freezes. If you see frost on an object, that means the temperature on that object reached 32 degrees.

Temperatures are not uniform. There can be a difference of a few degrees within 100 or 200 feet. Low-lying area tend to be cooler.

So it's possible to have an official air temperature of 35 degrees, yet see frost on some objects. Likewise, it can drop to 32 degrees officially, yet frost doesn't form.

If frost develops Saturday morning in Charlotte, it will be six days early, technically. That's because the N.C. Cooperative Extension Service, out of N.C. State University, says the average first frost in Charlotte (at the airport) comes Nov. 5. But there is a variation of 13 days on either side of that date, so an Oct. 30 frost is not really out of the ordinary.

According to the Extension Service, here are some other average first frost dates for the area:

Albemarle: Oct. 25.

Concord: Nov. 2.

Gastonia: Nov. 1.

Hickory: Oct. 20.

Lenoir: Oct. 21.

Monroe: Oct. 25 (this seems early, given that Monroe is southeast of Charlotte; but the National Weather Service's official observer is in a rural area south of Monroe, so it's possible measurements are made in a low-lying area).

Morganton: Oct. 18.

Salisbury: Oct. 26.

Shelby: Oct. 25.

Statesville: Oct. 19.

Wadesboro: Nov. 4.

The only South Carolina dates I could find came from a seed company, which said the average first frost date in Chester, S.C., is Oct. 20. That seems too early to me, so I discounted that. I'd assume the average date in Rock Hill and Lancaster would be somewhere around the Nov. 5 date.

TROPIC TROUBLE: The tropics are not finished for 2010. Tropical Storm Shary, a relatively weak system, is expected to move into the open Atlantic, encounter cooler water and strong wind shear, and dissipate this weekend.

But there is a stronger system in the deep southern Caribbean that is likely to become a named tropical storm, according to the National Hurricane Center. That system will affect Aruba, Bonaire and Curacao in the next day or two, then slide into the southern Caribbean.

Some long-range forecasters say this system eventually could be a Gulf of Mexico player by late next week. But late-season storms in the Caribbean are difficult to predict, so I wouldn't put much stock in any forecasts yet.

A storm to remember

Finally, after two solid days of severe weather, calmer conditions are returning to the Charlotte region today.

Autumn weather is returning, too (see below), but the storm system responsible for the damage across our area will not be forgotten. It's become a part of weather history.

The center of the trouble was a low pressure system that deepened rapidly Monday over the Dakotas and Minnesota, then eventually pushed northeast into Canada. It was storm of epic proportions, and its impact was felt all the way into the Southeast.

Shortly after 6:30 p.m. Tuesday, the barometric pressure in Bigfork, Minn., dropped to 28.20 inches. That's the equivalent of 955 millibars of pressure -- the same as you'd get in a Category 3 hurricane with winds of 110 to 120 mph.

Nearby International Falls, Minn., had a pressure of 28.24 inches at 4 p.m. Tuesday.

Bigfork's low pressure broke the record for the deepest storm system in Great Lakes history. The previous record was 28.27, set in the Ohio blizzard on Jan. 28, 1978. I lived through that event, and maybe one day I'll write about it.

The storm had a tragic impact. On Wednesday afternoon, a Notre Dame University student was killed while video-taping the football team's practice session. Declan Sullivan, 20, was standing on the 50-foot tower when a wind gust blew it over. The South Bend Regional Airport, 5 miles away, reported a 51 mph wind gust about the same time.

On Lake Superior, a reporting station recorded sustained winds of 68 mph and gusts of 78 mph early Wednesday morning. Waves were 20 feet on the lake -- the kind of waves you see in storms on the open ocean.

With the pressure so low, winds whipped around the system in a counter-clockwise motion. Those winds helped create tremendous shear in the atmosphere, so the thunderstorms that formed along a cold front being dragged eastward by the low pressure system turned into tornadic storms.

On Tuesday, there were 373 reports of tornadoes, damaging wind and hail. Among those were 46 tornado reports, including those from Lincoln, Catawba and Stokes counties near Charlotte.

On Wednesday, there were 32 more reports, including 14 tornadoes.

First Frost coming?: You might want to start planning ahead for the possibility of our first frost of the season, on Saturday morning.

It appears as if temperatures will fall into the mid 30s to the north and west of Charlotte, and the mid to upper 30s near Charlotte. Winds are forecast to be light, so frost is a possibility.

Halloween Outlook: It looks great. Temperatures will rebound from the chilly conditions expected Friday and Saturday morning, with highs Sunday around 70 degrees. Conditions should be clear to partly cloudy Sunday evening, with temperatures in the 60s.

Massive storm, and we're on the edge

Weather geeks are really in a frenzy about the deep storm system that is crossing the northern part of the United States today and Wednesday.

Although the Charlotte region will be 600 to 700 miles south of the storm's center, we'll get a bit of the action from this massive system that will make news headlines for the next day or two.

First of all, the worst of the storm will be felt in the Great Lakes -- Illinois, Wisconsin, Indiana, Michigan and Ohio. And the storm will be multi-faceted, with tornadoes on the southeast side, some snow on the western (cold) side, and strong winds on all sides.

The barometric pressure in this system is really low, if you can believe some of the numbers we're seeing today from Minnesota and Wisconsin.

I've seen a number of barometric pressure readings today in the lower 28's. That's the equivalent of about 955 millibars -- similar to a Category 2 hurricane.

Few of the hurricanes we've seen this year have had lower barometric pressures than the storm system crossing the Upper Midwest and Great Lakes.

As you might imagine, winds are whipping around this storm, because it's tightly wound.

What will it mean in the Charlotte region?

Today will be rather calm, actually. The clouds and fog this morning probably will break for some partial sunshine this afternoon, and temperatures will climb into the lower 80s. Dewpoint temperatures are in the 60s, as the southerly flow around the southeast side of the deep storm system drags warm air northward.

There'll be 70-degree readings up to the Canadian border today, east of the storm.

But severe weather will break out today, and the National Weather Service expects squall lines of thunderstorms to reach the mountains by tonight. Some of those storms probably will move into the Charlotte area by Wednesday morning.

The best chance for severe weather in our area probably will be Wednesday morning. Some showers will remain after a cold front pushes across the area sometime Wednesday, but look for partial clearing Thursday.

Next will come the cold air, dragged southward by the counter-clockwise flow around the back side of the storm system. Temperatures on Saturday morning probably will reach the middle 30s in some places around Charlotte, and that should mean the first frost of the season in parts of the Piedmont.

UP NORTH: The Storm Prediction Center has taken the unusual step of putting parts of Indiana and Ohio in the "high risk" category for severe thunderstorms and tornadoes today.

Sustained winds of 40 to 50 mph, with gusts to 70 mph, are expected today across the Great Lakes. Thousands of power outages already are being reported in Kentucky and Illinois, and you can look for those to spread eastward and northward during today and tonight.

One other thing to consider ... if you're planning to fly today to Chicago, Minneapolis or Detroit, plan on delays. Strong winds and severe storms could play havoc with aviation schedules up there.

Severe storm threat fades, but more rain coming

Just an update to my earlier post today ... the severe weather threat has ended for the Charlotte area, as the strongest energy with the low pressure system has drifted off to the east.

Despite all the thunder, lightning and warnings, less than 1/5 of an inch of rain has fallen so far today at Charlotte Douglas International Airport. But additional showers are likely later today, and we need them.

After a warm and partly sunny day Tuesday, we'll probably get another round of showers and thunderstorms Wednesday with a cold frontal's arrival.

Severe thunderstorm watch issued

An area of strong thunderstorms is crossing the Charlotte metro region Monday morning, and more thunderstorm activity is possible for the next few hours.

Severe thunderstorm warnings that were in effect earlier for several counties west of Charlotte have expired, and there were no reports of significant damage.

Bryan McAvoy, at the National Weather Service office in Greer, S.C., says strong storms are crossing northern Mecklenburg and adjacent counties shortly before noon. McAvoy says those storms could produce wind gusts of about 40 mph.

Heavy rain is falling in a number of places across Mecklenburg County.

A severe thunderstorm watch remains in effect until 1 p.m., covering all of the Charlotte area. The storm threat is being caused by a rather powerful autumn low pressure system that triggered 174 reports of tornadoes, damaging winds and hail Sunday.

Farther to the south, a tornado watch is in effect until 1 p.m. for parts of Georgia and South Carolina.

We'll continue to stay on top of the stormy conditions today.

A line of severe storms plowed into the North Carolina mountains around daybreak Monday, causing reports of damage in Swain, Franklin, Jackson and Macon counties. Those storms weakened considerably as they moved into slightly more stable air in the foothills.

The atmosphere is primed for trouble, and if you want proof, just take a step outdoors. After several days (weeks, really) of very dry conditions, it is quite humid. Dewpoint temperatures, a measure of humidity, have been in the 20s and 30s for the last several days. This morning, they're in the 60s. Those are summer-type readings.

And unlike some severe weather episodes, the warm and muggy conditions won't come to an end when the storm system passes our area later today.

It will remain warm and humid Tuesday, with high temperatures reaching 80 degrees under partly sunny skies. More 80-degree weather is likely Wednesday, but showers and thunderstorms will return. Then a cold front will move across the region, bringing a return of conditions more appropriate for late October.

When is cold air coming?

Don't get me wrong ... I enjoy warm -- even hot -- weather. But I also have a calendar on the refrigerator, and it says we're in the final third of October. And like a lot of other people, I'm wondering when that first blast of cold air will arrive.

And since my aerated, fertilized and seeded lawn could use more water (Wednesday's .11 of an inch is merely a start), I also wonder when rain will return.

There won't be cold weather or rain over the next several days. It'll reach the upper 70s today, cool to the lower 70s Friday behind a weak cold front, then recover to near 80 degrees Saturday, Sunday and Monday. And it'll be dry.

So when is the change coming?

You won't find the answer in the long-range forecasts.

This morning, I checked the 10-14 day predictions from the federal government (NOAA) and two of the best-known private companies, Accu-Weather and the Weather Channel. See if this sounds like a consensus:

NOAA: Above-average chance of rain, with above-average temperatures over the next 6-10 days and average temperatures overall over 10-14 days. That seems to indicate NOAA meteorologists think it'll be warm for 6-10 days, then cool down.

Weather Channel: Basically average to above-average temperatures for the next 10 days, with a good chance of rain next Tuesday and Thursday.

Accu-Weather: Solid chance of rain next week, but dry otherwise between now and Nov. 4 (the next two weeks). Their temperature forecasts differ widely from NOAA and the Weather Channel, with the prediction of a real cooldown for Halloween weekend. They're talking about daytime highs in the upper 50s on Oct. 30 and 31. Then they forecast a warmup in the first week of November.

I saw another forecast yesterday from New York-based Weather 2000 Inc., a private firm, and its meteorologists are calling for a cold air outbreak over the eastern United States for Halloween weekend.

There's a wild card in the forecast -- down in the Caribbean.

A tropical depression formed Thursday morning, and it probably will become Tropical Storm Richard by later today. Most computer models predict the system will become a hurricane in a few days.

The computers forecast the storm will cross Mexico's Yucatan Peninsula, and if it hasn't been wrecked by a trip over land and some southwest winds that could shear the top off the system, it could turn north or northeast in the Gulf of Mexico.

Should that system reach the Gulf coast of the United States, especially from Alabama eastward, it probably would link with a cold front that should be moving into the Southeast by the middle or end of next week. And that would bring a lot of rain to the Charlotte area.

Let's see ... by my quick count, the previous three paragraphs have the word "probably" twice; the words "could," "would" or "should" six times; and the word "if" once. So let's wait on that one, OK?

Woolly Worm's forecast: Snowy new year

I don't know if woolly worms gloat, but the winner of last year's Woolly Worm Festival in Banner Elk, Wilbur, did a pretty good job of predicting the winter of 2009-10.

Now we'll see if this year's winner -- a worm with a Charlotte-area connection -- is correct in his/her prediction that the winter of 2010-11 will have a cold and snowy start, a mild middle, and then finish with very cold temperatures.

The 33rd annual Woolly Worm Festival took place Saturday and Sunday in Avery County, and organizers estimate the event drew more than 23,000 people.

The festival features food, games and entertainment, but it's built around the woolly worm, a caterpillar who, according to folk legend, predicts the upcoming winter. That prediction is based on the hue of the creature's rings. Each ring represents a week of winter, and the darker the color, the worse the week.

Last year's winner, Wilbur of Chapel Hill, correctly predicted a cold and snowy winter.

Dr. Ray Russell, an Appalachian State University faculty member who operates the popular Ray's Weather website, says the winter of 2009-10 produced 134.3 inches of snow in Beech Mountain and 83.6 inches in Boone. He says it was the third-worst winter in history in the N.C. mountains.

So what about this year?

The winning worm in Sunday's championship race was owner and "trained" by 5-year-old Cole Peurifoy of Concord, above. I don't have the worm's name, but his rings indicate the Weeks 1-5 and 12-13 will be the worst.

Incidentally, the rings were interpreted this year by Tom Burleson, a 7-foot-2 former basketball standout with North Carolina State University and in the NBA. Burleson has legitimate woolly worm-interpreting credentials. He's from Avery County and still lives there.

The forecast, courtesy of Cole Peurifoy's worm:

Week 1 (Dec. 20-26): Cold with snow.
Weeks 2-4 (Dec. 27-Jan. 16): Extremely cold.
Week 5 (Jan. 17-23): Ice storm.
Weeks 6-11 (Jan. 24-March 7): Average to mild weather.
Weeks 12-13 (March 8-20): Very cold.

Ray Russell's Forecast: Russell doesn't agree with the woolly worm. Disdaining the color of the woolly worm's rings and paying heed to scientific factors such as La Nina and other short-term climate conditions, Russell is predicting the winter of 2010-11 will be mild and less snowy than last year.

His mountain and foothills snowfall predictions -- 75 inches at Beech Mountain; 32 inches in Boone; 11 inches in Asheville; and 7 inches in Hickory.

You can check out his information at www.raysweather.com

Cooler and windy, but no frost in Piedmont

The strong cold front that pushed through the Charlotte area earlier Thursday (and produced a grand total of about 1/10 of an inch of rain) will bring windy conditions Friday and our coldest temperatures so far this season.

But the Piedmont should be safe from frost, this time around.

The biggest problem for the area could come Friday, when sustained northwest winds of 15 to 25 mph (with gusts to 35 mph) and low humidity will increase the fire danger.

The National Weather Service says it isn't expecting to issue a fire watch for the Piedmont but will do so for northeast Georgia and the South Carolina Upstate. However, forecasters say, the wildfire danger will be higher than usual in the Piedmont on Friday.

Daytime temperatures in this colder air mass will remain mild, actually. We'll have highs in the lower 70s for the next few days, and then into the middle 70s by early next week.

But with dry air and no clouds at night, the morning lows will be chilly. Some places around Charlotte will see readings in the upper 30s on Saturday, Sunday and Monday mornings. The frost threat is limited to higher elevations, the National Weather Service says.

This all means a beautiful weekend for seeing the fall colors in the mountains. And it also means that for the first time this football season, you'll need a coat at high school games Friday night and college games Saturday evening.

That also goes for fans headed to Charlotte Motor Speedway for the big races Friday and Saturday evenings.

That wet stuff? It's called "rain"

That strange wet stuff falling from the sky shortly before daybreak this morning is called "rain."

Once upon a time, we saw rain frequently, but since the middle of August, it has fallen only a few times. And it won't last long today.

A cold front is crossing the Charlotte region this morning, and it has touched off scattered showers and even a few thundershowers. People who live near Lake Norman and across the Cabarrus County line into Kannapolis got a middle-of-the-night wake-up call, about 3 a.m., when a small but strong thunderstorm crossed that area.

The storm produced winds of up to 40 mph, but it was short-lived.

The rain that's falling this morning across the region will move swiftly off to the east, and clearing will follow today. It could be the middle of next week before we have a solid chance of rain again.

We're also still watching for the possibility of gusty winds on Friday, especially in the mountains.

Winter Outlook: Brad Panovich, the chief meteorologist with our news partner, WCNC-TV, has come out with his winter forecast.

Brad is calling for rather mild temperatures and less snow than usual in the Charlotte area -- but a higher-than-average chance of ice storms.

Brad notes that we have a La Nina pattern this year, which typically means warm and dry winters in the Southeast. But there also is a negative Atlantic Oscillation (NAO) condition, which tends to drive cold air fairly deep in the eastern United States.

He predicts the main storm path will remain north of the Charlotte region, but we'll be close enough to get hit a few times. And if I'm translating his forecast properly, the NAO will drive cold air far enough south on occasion to leave us prone to ice storms. The threat would be freezing rain, rather than snow, because La Nina will prevent us from getting into the truly cold air.

His forecast also calls for dry and warm conditions along the eastern third of the Carolinas.

Here's a link: www.wcnc.com/news/local/brads-winter-forecast-average-temps-higher-ice-chances-104865279.html

No strong winds, please

A cold front will cross the Carolinas later tonight and early Thursday, and some computer models indicate Friday could be a very breezy day across the region.

We wouldn't want that.

Gusty winds Friday would be a problem for two reasons -- a fire threat across the entire region; and trouble for those planning to drive to the mountains and see the colorful leaves this weekend.

You don't need me to tell you how dry it's been recently. Many of us are praying that the cold frontal passage will trigger enough showers or thunderstorms to moisten the ground -- to either water the grass seed that some of us have planted, or make it wet enough for the lawn-work procrastinators to get their aerating and seeding done.

It's not likely, because there doesn't seem to be much chance of significant rain.

Very dry conditions since mid-August have put us in a position where gusty west or northwest winds could create a big-time wildfire threat. We've been lucky so far, with only a handful of wildfire outbreaks in recent weeks.

For those planning trips to the mountains this weekend, a windy Friday could ruin some of the color show by blowing leaves out of the trees. This figures to be one of the most colorful weekends of autumn 2010 in the North Carolina high country.

We should know more about the wind threat by Thursday morning.

Hot, but no record; and tropics still active

The temperature is soaring into the middle 80s this Monday afternoon, and while the National Weather Service says a record high is possible today at the Greenville-Spartanburg station (the record there is 86), nothing like that is expected in Charlotte.

Still, this mid-October heat wave is what you'd expect, given the type of steamy summer we just came through.

Today's high is expected to reach 85 or 86 degrees, and the record for the date is 90, set in 1939. More of the same is predicted Tuesday, when the record high is 89, set in 1919.

All of that got me wondering about the latest 90-degree and 80-degree days ever in Charlotte.

Our latest-ever reading of 90 degrees was on Oct. 13, in 1954. That was the year in which numerous heat records were set, and I've heard stories from old-timers that it was an absolutely brutal summer.

Our latest 85-degree day was on Nov. 2, 1961. That year featured a version of a heat wave at the beginning of November, with the temperature reaching the mid 80s daily from Nov. 1-4. Incidentally, in case you're wondering, we got 13 inches of snow that winter (1961-62) in Charlotte. It snowed three times in January 1962.

Finally, our latest 80-degree day happened just three years ago -- an 80-degree reading Dec. 10, 2007.

Our earliest 80-degree day was Feb. 2, 1989.

Tropical Update: As of 2 p.m. Monday, the National Hurricane Center still hadn't declared an area of stormy weather off the coast of Honduras to be a tropical storm, but it likely will happen later this afternoon. It will be Tropical Storm Paula, and the computer models are all over the board with predictions on where the system will go.

I haven't seen any predictions, however, that the system will affect the U.S. mainland. The three most likely scenarios seem to be: a.) Moving inland in Belize and Mexico's Yucatan peninsula, and falling apart; b.) Drifting southward into Central America; c.) Moving northeast, clipping the west coast of Cuba and then curving east, near the Bahamas, and then out into the open Atlantic Ocean.

The storm that will be Paula has formed in the same area of disturbed weather that produced Tropical Storm Otto last week, and it might not be finished. Some meteorologists think another system could develop in the same general area later this week.

Too early for mountain colors

The taste of autumn that we received in the past week brought out some new wardrobes and got many of us thinking about the arrival of fall, but don't race to the mountains this weekend, expecting a bright show of colors.

The latest check indicates leaves on some trees are changing colors, but you'll have to travel to the higher altitudes to see them.

As of Thursday, colors were being seen in the trees above 5,000 feet. That's mostly in the Mount Mitchell, Grandfather Mountain and Craggy Garden areas.

Forestry officials say it will be the middle of next week, or possibly even next weekend, before the autumn color show reaches the 3,500- or 4,000-foot level.

In other words, you'll probably see some spectacular yellows and reds next weekend along the Blue Ridge Parkway, near Boone and then down around Mount Pisgah. Dr. Howard Neufeld, an Appalachian State University professor who follows the changing of the leaves each year, says some yellows and oranges are being seen among the greenery in the Boone area, but it's still a bit too early there, too.

Some horticulturists had worried that our dry and hot late August and September would cause the leaves to turn brown and fall early. That happened in a few places, but late-September rain seemed to save the day.

The peak time in the mountains -- especially at elevations of 2,500 to 4,000 feet -- likely will be around Oct. 17 to 28.

Down in the Piedmont, naturally, it'll be later.

The latest prediction is that trees in the foothills will be at full color in the last week of October -- and a few days later in the Piedmont.

Changes Ahead: If you're a fan of warm weather, you'll love the next few days, as temperatures soar well above average in the Charlotte area. Under sunny skies, we'll have afternoon readings in the mid 80s this weekend.

But don't get too used to it, as some big changes are coming.

Most of the computer models indicate a change to much cooler and wetter weather, beginning around the end of next week. There are indications the chilly conditions could continue through the rest of the month.

Our afternoon highs by the end of next weekend probably will struggle to get out of the 60s.

Arizona twisters, Atlantic hurricane, and our 80s

We've got a couple topics to cover today, and the first is the outbreak of tornadoes before daybreak Wednesday in Arizona.

It looks as if there were four twisters, mostly in the northern part of the state, around Flagstaff. A low pressure system that was parked over central California spun up the severe storms, and the tornadoes destroyed about 200 homes.

I heard someone mention on a TV newscast today that October tornadoes in Arizona are almost unheard of, so let's go to the record book.

In the decade from 2000 and 2009, there were 38 tornadoes reported in Arizona. Is that a lot? How about these figures, for the same 10 years:

Texas: 1,526

Oklahoma: 529

North Carolina: 319

South Carolina: 313

Alaska: 3

OK, so tornadoes are pretty rare in Arizona, unless you're comparing it to Alaska, in which case Arizona is like Tornado Alley.

On average, there are almost four tornadoes a year in Arizona. Of the 38 in the last decade, five were in October, including three on Oct. 18, 2005. Five twisters in a month is actually more than the state's average, so the point is that tornadoes any time of year in Arizona are rare.

By the way, the low pressure system responsible for the stormy weather out West is weakening and won't have such an impact as it moves into the upper Midwest this weekend.

The Tropics: As we mentioned yesterday, Subtropical Storm Otto has become Tropical Storm Otto and is crawling along at 2 mph. The National Hurricane Center still thinks Otto could become a hurricane, but the forecast track continues to be out into the open Atlantic.

My brother Michael, who is even more of a Weather Guy than the Weather Guy himself, points out that my comparison of subtropical and tropical storms in Wednesday's blog entry failed to mention a key difference -- the temperature of the atmosphere in the center of the storm systems at different altitudes.

As he notes, a subtropical system has warm air near the surface and cold air aloft. A tropical system is warm in the center, from bottom to top.

And For Us: It's the same old pattern we saw in August and September, and I'm betting it's the same pattern we'll see much of this winter. High pressure is locked over the Southeast, which means it'll be warm and dry for the foreseeable future.

Those morning lows near 40 degrees earlier this week will be replaced by lows closer to 50, over the next few days. But we'll see a real difference in the afternoon. It didn't reach 70 earlier in the week, but we'll be looking at highs near 80 through early next week.

In fact, it could reach 82, 83 or even 84 degrees in Charlotte on Saturday or Sunday. Maybe the Chicago Bears will have problems with our heat when they come to town for Sunday's game.

Baseball Playoff Weather: No problems for today's Major League Baseball playoff games. It'll be in the upper 60s and dry at gametime early this evening in Minneapolis, for the Twins' game (and probable loss, given their history) against the New York Yankees.

In San Francisco, it'll be in the upper 50s for the first pitch of the Giants' game against the Atlanta Braves.

And in St. Petersburg, it'll be 80 degrees and sunny when the Rays face Texas in Game 2 of their series. Of course, that game's being played in a dome, and from the looks of attendance at Rays' games, most everyone is outdoors enjoying the sunshine.

Subtropical storm? What's that?

A subtropical depression formed Wednesday morning east of the Bahamas, and since this system almost certainly will never affect the U.S. mainland, we can focus on something other than the storm's track.

For example, what does "subtropical" mean, and how is such a storm different from a "tropical" system?

Subtropical Depression 17 is expected to strengthen into a storm, and it'll get the name Otto. After that, all the computers agree that the system will move swiftly to the northeast, away from North America and out to sea.

It probably will convert to a tropical storm and might even become a hurricane.

And it's interesting to note that Otto would be the 15th named system this year. As I recall, that's pretty close to all the predictions, and it's indicative of a busy season. However, since no major storms actually made landfall in the United States, most people probably will think of 2010 as a quiet tropical season.

Anyways ... back to the issue at hand -- tropical vs. subtropical.

A tropical system gets its energy from the ocean's warm water. Its center, called the core, is warm. The strongest winds and heaviest thunderstorms tend to be near the center of a tropical system.

A subtropical system is different. Often, it's a low pressure area along a cold front that moves into the south Atlantic or Caribbean. Gradually, the storm system stops getting energy from the cold front and instead begins receiving fuel from the warm water below. Thunderstorms in the system give off latent heat, and that helps develop the warm core.

In a subtropical system, the strongest winds tend can be several hundred miles from the center. In other words, it's not organized quite as well. But subtropical storms can have sustained winds of up to 65 or 70 mph.

Often, subtropical systems develop a warm core and convert to tropical systems. The strongest winds and storms move closer to the center, and the system becomes better organized.

There's one more term to know -- extratropical storms. That's a system that was tropical in nature (either a tropical storm or hurricane) but moves into colder waters and loses its tropical characteristics.

Record heat to record cold?

Vince DiCarlo, who retired last year from the National Weather Service office, reminded me frequently that "averages are what you get from two extremes."

For example, Charlotte's rainfall total in September was about 4.1 inches -- above the monthly average.

But who thinks September was a wet month around here?

Our lawns turned brown in a relentless string of hot and dry days, until the last few days of the month, when it rained cats and dogs. Overall, though, rainfall was a big above average.

Our recent temperature swing is another example. A week ago Saturday, we broke a record (for Sept. 25) in Charlotte with a high of 94 degrees. Tomorrow (Wednesday) morning, we could be near record-low temperatures, with the thermometer in the vicinity of 40 degrees.

The record low for Wednesday is 38, set in 1935. This morning, we flirted with a record, dropping to 40 degrees (the record was 38, set in 1974).

The average high and low temperatures at this time of year are in the upper 70s and mid to upper 50s. But it seems as if we're mostly at one end or another of the extremes.

By the way ... I did a little checking of recent years, to see if our 40-degree reading this morning was unusual. Looking at the record book since 2006, it does appear as if it was a bit early to be that chilly.

Last year, our first day of 40 or colder was April 18 (35 degrees). October 2008 was a chilly month, as it dropped to 42 on Oct. 2 and got down into the upper 20s by the end of the month. In 2007, temperatures didn't fall to 40 or below until the end of the month. In 2006, it was the middle of October.

Either way, we can expect dry weather and a gradual warm up for the rest of this week. High pressure is taking control of the eastern United States, and we could be near 80 degrees for afternoon readings in a few days.

Talking Tropics: There's another system in the Caribbean, and the National Hurricane Center gives Invest 97L a 60 percent chance of becoming a tropical depression or tropical storm. It's north of the Virgin Islands, but the system is taking a beating from upper-level westerly winds (shear) and is not forming very quickly.

Some meteorologists speculate the area of disturbed weather could become two separate tropical systems -- one north of the Virgin Islands, carried back out to sea; and other south of the Dominican Republic and Haiti.

What happened at the coast? And how about us?

The unbelievably heavy rain that clobbered the Carolinas coast is proof once again that it doesn't take a Category 5 hurricane to create big weather problems.

Dying tropical storms, if given some help, can trigger deadly floods, tornadoes, and lots of other trouble.

In some ways, the situation Wednesday and early today on the coast looks similar to 1999, when Hurricane Floyd pushed ashore and set off flooding that killed 51 people. The similarities -- a tropical weather system was involved, and it moved into a stationary front.

Floyd was much, much more powerful than the wimpy Tropical Storm Nicole which died near Florida late Wednesday. But the energy from Nicole was absorbed by a pretty potent non-tropical storm system that formed off the South Carolina coast.

Meanwhile, a stationary front was along the Carolinas coast, separating humid air on the east from cooler air to the west. As low pressure neared the front, it set off very heavy rain.

The National Weather Service in Wilmington says rainfall totals will be in the vicinity of 21 to 23 inches (over a four-day period) when all is said and done.

You know how bad it was? It was so bad that CBS sent meteorologist Dave Price to Wilmington. And the Baron of Bad Weather, Jim Cantore of the Weather Channel, is on the coast.

Meteorologists told you the cut-off between heavy rain and lighter precipitation would be close to the Charlotte area, and they were right. Albemarle got more than 4 inches of rain. Charlotte, about 35 miles to the west, got about 2/3 of an inch. You could draw a line from Greensboro, down across Lexington, Albemarle, eastern Anson County, and then down to Florence ... and everything east of there got walloped by the storm.

Now what?

A taste of autumn, that's what! There's a weak low pressure system over Georgia that will push across our area during the day. The sun might come out at times this afternoon, but that weak low might trigger a few showers or thundershowers.

Clearing will follow tonight, and it'll be nice for a few days, with highs in the 70s and lows in the 50s.

The computers can't agree on Sunday and Monday, with some signs that another coastal storm system could bring rain to the Charlotte area. But after that, it'll turn even more fall-like, with sunshine and highs only around 70 degrees by next Tuesday and Wednesday.

11:45 update ... forget about Nicole

Ahh ... the wacky world of weather!

At 10:30 this morning, the tropical weather system south of Florida was expected to become Tropical Storm Nicole, cross southern Florida and head for the Carolinas.

Not so fast!

Yes, the tropical depression is now Tropical Storm Nicole, with top sustained winds of 40 mph. But forget about the storm crossing Florida and heading for the Carolinas.

This system has been poorly organized and, frankly, a bit weird from the start. Nicole's strongest winds are about 150 miles east and southeast of the center. And now there are two changes in the forecast:

1. Nicole is expected to pass east of Florida, cross the northwest Bahamas, and move into open waters.

2. It is forecast to dissipate within 36 hours. It will die at sea, maybe 150 or 200 miles east of Jacksonville, without ever reaching the Carolinas.

Does that mean none of the rain is coming to the Charlotte area and the rest of the Carolinas? No, not at all.

Nicole will dissipate because it will be gobbled up by a low pressure system forecast to develop later today off the South Carolina coast. If I may borrow a reference from the distant past, it's like the old Pac-Man game, where one of the little critters gobbles up another.

Once the low pressure system forms off the S.C. coast, it will spread rain inland.

However, this probably means we won't have to worry about flooding rains in Charlotte. Expect an inch or so, from later today until Thursday morning. It'll be great for the lawns.

Nicole: Trouble or relief?

Tropical Storm Nicole appears destined to pay the Carolinas a visit.

But how close will the storm's impact come to the Charlotte area? And how much of the Charlotte area?

The bigger question: Will Nicole be drought relief for Charlotte, or a troublemaker?

That all depends on the storm's track, and meteorologists are having a tough time with this system. On Wednesday morning, the disorganized center of the system was about 150 miles south of Key West. Steering winds will carry the storm northward, probably along or near the east coast of Florida.

So far, the depression's strongest winds have been on its eastern side, which means Florida could escape the worst of it (although "worst" might not be the right word, because Nicole won't be a strong tropical storm).

Then, as the storm moves toward anticipated landfall in the Carolinas, it is forecast to lose its tropical characteristics.

When that happens, the area of rainfall widens to all sides of the storm.

The computer models can't agree on how far inland the heavy rain will spread, but it could be very close to the Charlotte area.

Worst-case scenario ... Nicole (or whatever it is, at that point) makes landfall somewhere around Myrtle Beach on a north-northwest track. That would bring 2 to 4 inches of rain to Charlotte, especially along and east of I-77. The farther east you go, the heavier the rain. Places like Richmond and Scotland counties could get 5 inches.

The most likely scenario ... Nicole makes landfall around Wilmington, moving north. Rain moves into Charlotte, but about 1 to 1.5 inches falls. West of I-77, totals are even less. For example, Shelby might get only 1/4 to 1/2 of an inch. That much rainfall for Charlotte would be good.

We'd all get our lawns aerated and make a run on the garden stores for seed and fertilizer.

The rain that moved through the Charlotte area before daybreak was not connected directly with the tropical system. But the precipitation totals give a hint as to what we can expect later. About 1/5 of an inch fell at the airport. A gauge in Matthews measured about 1/3 of an inch. And nearly 1/2 of an inch fell in Monroe.

The farther east you go ...

So here's what to expect: We'll get a break from the rain for a good bit of the day. It might shower once or twice, but that activity will be scattered. Later this afternoon, precipitation from the tropical system will move up the coast and then inland.

Steady rain will begin falling this evening and continue overnight. By later this afternoon, we should have a better idea on what to expect in rainfall totals.

The rain should end Thursday morning, and partial sunshine could return by afternoon.

Look for clear and cooler weather the rest of the week, after a high around 80 Thursday. By Sunday, daytime highs will be near 70.

More later ...