Thursday, January 31, 2013

Storms gone ... so what's next?

The meteorologically bizarre turn of events in the Charlotte region over the last 48 hours is history, and we're back in a more typical late-January pattern.

So that begs the question ... what happens next for our weather?

First, let's look at a few of the highlights from our wild Wednesday weather:

-- Our morning low of 62 degrees broke a record for the warmest low temperature in Charlotte for the date. The old mark was 59 degrees, set in 1914.

-- Our afternoon high of 77 degrees barely missed tying the record for the date. The mark is 78, set in 2002.

-- While most of us in the immediate Charlotte area received about 3/4 of an inch of rain, there were some staggering totals in the mountains. The line of thunderstorms chugged to a near-halt for several hours in the high country. The result was flooding. Boone recorded 5.9 inches of rain. Asheville's total of 2.76 inches set a record for the date.

-- As the cold front pushed across North Carolina, we briefly had a situation in which winter had returned in the west, but it was still spring in the east. At 3 a.m., the range of temperatures in the state was 53 degrees. It was 19 in Franklin, in the western mountains, but 72 on the Outer Banks.

For the next few days, we're back in what meteorologists call an amplified pattern. That means there's a big dip in the jet stream, with Alberta clipper low pressure systems diving into the Southeast, bringing quick shots of snow and reinforcing blasts of cold air.

One of those systems will cross the mountains tonight, bringing 1-3 inches of snow to the ski resort areas. And behind it, temperatures will be colder Friday.  We'll be lucky to get above 40 degrees Friday in Charlotte.

Another clipper will zoom through the region Saturday night.  This time, precipitation could start as rain in the mountains but will change to snow, with another accumulation.  And this system could slide far enough south to bring light snow into Hickory and Statesville -- and possibly even some flurries to Charlotte.  Of course, you might have to get up at (or stay awake to) 3 a.m. Sunday to see it.

After that, it'll be chilly and windy again Sunday, before turning milder for most of next week.

The longer-range patterns continue to advertise generally mild weather for at least the first half of February. There are no signs of really warm weather, but temperatures seem to be headed for seasonal to slightly above-average readings.

At this time of year, the average highs and lows are 52 and 31. That's 2 degrees warmer than at the coldest point, in mid-January.  We're on the way back up.

So the first half of February looks like mostly 50s and low 60s for highs, if the computer models have it right.

Beyond that is anyone's guess.  Will we return to cold weather for the last few weeks of winter, or will we stay seasonal into March?  The longer-range models don't agree.

Wednesday, January 30, 2013

Winter tornadoes are especially treacherous

The powerful line of thunderstorms plowing its way eastward toward the Charlotte region Wednesday afternoon is carrying a real threat to lives and property.

Any doubts about that were dispelled about 11 a.m., when a tornado barreled through Adairsville, Ga., a town north of Atlanta on Interstate 75.

According to early reports, the funnel cloud damaged a McDonalds restaurant and blew dozens of vehicles off nearby I-75.

The timing of this storm system could make it especially treacherous in the Charlotte region.

A few things to remember about these unusual winter severe weather outbreaks:

-- Many of these storms are low-topped.  That is, the cloud tops don't stretch 50,000 or 60,000 feet into the atmosphere, as is the case during warm-weather seasons.  The tops of these storms can be much lower.

-- Because of those low tops, these storms often contain no lightning.  They can roar into an area with little warning, causing considerable wind damage.

-- Because of the atmospheric conditions in these winter severe weather outbreaks, the storms often don't weaken when the sun sets. Overnight storms can remain quite strong, as was the case early Wednesday across Tennessee and Kentucky.

We'll keep you updated on developments during the afternoon and evening.  One trend to watch for is the development of what meteorologists call "discrete" storm cells.  These storms form ahead of the main squall line, and they are often responsible for tornadoes.  There are signs of these discrete cells forming Wednesday afternoon over Georgia, moving east-northeast.

Monday, January 28, 2013

Severe storm possibility Wednesday

Just three days ago, we were dealing with sleet, freezing rain, school closings, and hundreds of motorists smashing into guardrails and other vehicles.

Now we're talking about 70 degrees and a chance of damaging winds and tornadoes in two days.

A brief switch in the upper atmospheric steering currents will allow a return of very warm weather to the Carolinas for about 48 hours, starting later today. But that will end Wednesday with a strong cold front and the threat of severe weather.

After another cloudy and cool afternoon today, with high temperatures probably only reaching the upper 40s, the pattern change will start tonight. Warmer air will arrive from above, probably trapping cooler air near the surface and causing fog in the early-morning hours.

But once the sun rises, mixing the atmosphere Tuesday morning, the fog is expected to dissipate in a hurry, and we'll see temperatures reach the upper 60s.

Wednesday also will be warm, but a strong cold front will be approaching the region by late morning and afternoon.

Harry Gerapetritis, of the National Weather Service's office in Greer, S.C., said there will be very strong winds in mid levels of the atmosphere in advance of the front, and some computer models indicate those winds will be transported to the surface as the front approaches.

In addition, heavy rain is possible in the mountains and foothills, and those areas already have received 6 or more inches of precipitation in the last few weeks. So flooding also will be a threat.

"Both a flash flood watch and a high wind watch could be needed" in the mountains for Tuesday night and Wednesday, Gerapetritis said.

In the Piedmont, the threat is expected to develop after midday Wednesday, when the cold front approaches.

Gerapetritis said a few of the thunderstorms could become severe, especially in the Interstate 77 corridor of North Carolina, and in the South Carolina upstate.

"Damaging wind gusts will be the primary threat, but isolated tornadoes will be possible as well," he said.

His assessment is supported by the Storm Prediction Center in Norman, Okla.  In fact, SPC meteorologists have painted a large area of the South and Midwest -- stretching from Texas to central Illinois and Indiana -- for a threat of severe weather Tuesday. Then on Wednesday, the severe threat area stretches from the Gulf Coast to Virginia and southern Kentucky.

Behind all this will be a return to cold and stable conditions for several days.  High temperatures will only reach the middle and upper 40s Thursday through Sunday, but there are no signs of low pressure areas that could bring another threat of frozen precipitation.

In fact, some of the longer-term models point to a rather mild (even warm) period for at least the first half of February. We'll be talking more about that in coming days.


Friday, January 25, 2013

What's worse ... sleet or freezing rain?

The winter storm system moving across the Carolinas today is bringing all three types of precipitation -- snow, sleet and freezing rain.

We won't have to worry much about snow, as a "nose" of warm air several thousand feet up in the atmosphere is melting the precipitation as it falls. Some of that is refreezing into sleet, and some is reaching the ground as rain -- then freezing.

Anyways, since we're seeing a little of everything this morning, here's a quick primer on how it forms.  And I'm including my two cents' worth on what's worse ...

SNOW

This requires cold air in all levels of the atmosphere.  The only areas seeing snow today are in the northwest mountains, because the "warm nose" (I'll explain this later) isn't expected to reach as far north as the Boone area.

Power outage impact: Usually none, unless the snow is very heavy.

Road impact: Considerable, although crews usually can manage snow with plows and salt.

SLEET

For sleet to fall, we need a relatively thin column of warm air in the middle levels of the atmosphere. Precipitation starts falling as snow, melts on its way down and forms rain droplets, then freezes back into ice pellets as it moves within a few thousand feet of the surface.

Power outage impact: None.

Road impact: Intense.  Sleet causes big problems on the roads, as it tends to melt when reaching the surface and then freezes immediately.  Also, sleet tends to fall when precipitation is heavier. The overwhelming volume of sleet causes pockets of frozen pebbles to form on roads.

FREEZING RAIN

For freezing rain to fall, we need cold air at the upper levels, and then relatively warmer air all the way to the ground. But the surface levels have to be at or below freezing.

Power outage impact: If ice accumulates 1/4 of an inch, tree limbs can fall onto power lines, and we have trouble. When ice accumulates to 1/2 inch or more, there can be widespread problems.  Accumulations in the Charlotte area from today's system are only predicted to be 1/10 of an inch.

Road impact: Often, the main travel lanes on major roads remain in pretty good shape during freezing rain. Ice tends to form on the curbs -- and, of course, on bridges and overpasses, where the road surface is colder. Sidewalks are especially dangerous.  One other thing -- downhill sections of roads tend to get ice, too.  I'm sure there some explanation for this, but you'd have to ask a Physics teacher.

Wednesday, January 23, 2013

Farmers' Almanac not shutting down

We interrupt coverage of Friday's potential winter storm system with some really important news.

The editor of the Farmers' Almanac said Wednesday morning that the annual publication, which is 196 years old, will continue to be printed.

That was in some doubt after an announcement earlier this week that the manufacturing facilities at the almanac's headquarters in Lewiston, Maine, will be shutting down. That closure will eliminate about 75 jobs.

Peter Geiger, the Farmers' Almanac editor, says the issues that have been printed at the Maine plant since 1955 had been used for promotional purposes. Geiger, the parent company of the Farmers' Almanac, produced a variety of promotional materials at the plant, Peter Geiger said.

But the Farmers' Almanac that you see on shelves in grocery stores, magazine racks and book stores was printed at another plant, in Wisconsin.

The Farmers' Almanac remains interesting reading. It is loaded with facts -- some obscure, some of real-life value.  It also contains a number of other articles, but its noteworthy appeal is meteorology.

The almanac, of course, contains weather forecasts that are produced far in advance -- more than a year in advance, for some months. The authors say their predictions are based on a number of scientific principles, and considering the inconsistencies of computer models used by the National Weather Service and other meteorologists, it's sometimes tough to criticize the Farmers' Almanac methods.

Geiger says the almanac is "much more than just a physical product. It's a way of life, a belief that you can live life more simply, naturally, and in harmony with the world around you."

By the way, the almanac's forecast for the next few days in Charlotte is "mild with showers."  Oh, well ... you can't get them all right.

Tuesday, January 22, 2013

Another Friday, another iffy forecast

It would be easy for meteorologists if arctic air was in place across the Carolinas, and a big low pressure system was moving out of the Gulf of Mexico toward the region.

That would mean a big winter storm.

But as was the case last Friday, a storm system expected to affect the region this Friday won't have all the ingredients needed to produce a sure-fire, lock-cinch wintry forecast.

Last Friday, the powerful low pressure system was lacking cold air. It got cold enough, briefly, for a few bursts of snow. But for the most part, that was a serious rain-maker.

This week, arctic air will be in place. The questions surround the storm's path and the amount of precipitation.

The cold air arrived early Tuesday and won't really leave this week, although it will become slightly modified across the Southeast. By Thursday, high temperatures might be in the range of 45 to 48 degrees in Charlotte.

The low pressure system hasn't formed yet. It will develop off a larger storm in the Pacific, then will follow a path into the western United States, across the Midwest, and then eventually into the Southeast or Mid-Atlantic.

The computer models have been evolving over the last 24 hours, and that probably will continue to happen for another 24 to 48 hours.  Monday at this time, the Friday event looked like nothing for the Carolinas. It appeared as if low pressure would track along the Ohio Valley and bring some major snowfall to places like Ohio, Pennsylvania, New York, and New England.

But some of the computer models have begun forecasting the low will dive a bit, into the Southeast.

Precipitation amounts still look light, but with arctic air in place when something starts falling from the clouds Friday morning, it wouldn't take much to cause problems.

Temperatures could be in the upper 20s and low 30s when something -- snow, sleet or rain -- begins falling. If it's rain, the precipitation will freeze on surfaces (especially bridges, overpasses, tree limbs and wires). That's the working definition of freezing rain.

Right now, there is nothing pointing toward a major freezing rain event for the Charlotte area. But there is enough input from computer models to show a few hours of light freezing rain, and that would be enough to bring some big business to auto body shops.

Farther to the north -- let's say, along the I-40 corridor -- the precipitation would be more likely to start as snow before changing over to sleet or freezing rain. Some of the computer models show Hickory and Statesville remaining below freezing for much, if not all, of Friday.

There's a long way to go yet.  If the models shift the storm back to the north, we could be looking at a bit of sleet or freezing drizzle Friday, but nothing else.

As WCNC-TV chief meteorologist Brad Panovich notes, "This one bears watching."

Monday, January 21, 2013

Inauguration -- today's near-miss, and some history

Today's inauguration ceremonies for President Obama will take place under fairly nice conditions for this time of year.

Temperatures reached 60 degrees Sunday in Washington, and although it'll be quite a bit cooler today, the weather still will be better than what you'd expect in the nation's capital for Jan. 21.

If the ceremony were taking place eight hours later, or 24 hours later, it would be a lot different -- and not nearly so nice.

And in looking at history, you get even more appreciation for today's mild conditions. Some past U.S. Presidents have been inaugurated in horrible conditions.

For the official swearing-in ceremony at noon today, the forecast is for partly sunny skies and temperatures in the mid 40s. The average high for Jan. 21 in Washington is 43 degrees, and the temperatures might reach the upper 40s during Monday afternoon's inaugural parade.

A strong cold front, accompanied by a weak low pressure system, will cross the Mid-Atlantic later Monday. Snow could break out by late afternoon, temperatures definitely will be tumbling. All this will be accompanied by a stiff northwest breeze.  It's possible that an inch of snow could accumulate this evening.

Tuesday's high temperatures in Washington won't get out of the 20s, so it's a good thing the calendar has placed the inauguration today.

But as I said earlier, it could be worse.

The National Weather Service's office in Baltimore-Washington has produced a nice feature article, complete with photos, on the history of weather for the inauguration.

Anyone of my era probably remembers the inauguration of John F. Kennedy in 1961. The event already was historic, because Kennedy came into office as part of a new era in politics, as a fresh political face. He also came into office a day after an 8-inch snowstorm buried Washington.

Old video of the swearing-in ceremonies and subsequent parade make it look as if the inauguration took place in Duluth, not D.C.

Some other interesting tidbits from history ...

First, you'll remember that until Franklin D. Roosevelt's second inauguration in 1937, the event took place March 4.  In 1909, William Howard Taft's events were moved indoors because of an early-March snowstorm, with 10 inches of the white stuff. Winds knocked down trees and power poles.

A cold rain fell in 1841, when William Henry Harrison was sworn in. He caught pneumonia and died a month later.

In 1937, for the first Jan. 20 inauguration, a nor'easter moved up the East Coast. Temperatures were in the mid 30s, and more than 1 3/4 inches of rain fell in Washington. FDR insisted on riding in the inaugural parade in an open car.

Ronald Reagan's two inaugurations made history -- in different ways. In 1981, it was 55 degrees when he took the oath of office at noon. That's the warmest ever for a Jan. 20-21 inauguration.

But four years later, at his second inaugural, the parade was canceled in the wake of the worst arctic outbreak in the eastern United States in decades.  That was the outbreak that produced a low temperature of minus-5 degrees in Charlotte.  It was 7 degrees at noon that day in Washington, with wind chills of 20 to 25 degrees below zero.

Check out the Weather Service's article here http://www.erh.noaa.gov/lwx/Historic_Events/Inauguration/Inauguration.html


Friday, January 18, 2013

That was one crazy weather week!

The week has not ended, but it appears as if our wild weather has, fortunately.

We've gone from late spring, to fall, to winter -- all in a span of five days. We've tied or broken records for warm temperatures and rainfall. We've had thundersnow, regular snow, and flooding.

A blast of cold air -- the coldest we've seen in probably two years -- is coming early next week. But we'll have time to discuss that later.

In the meantime, let's take a look at some of the amazing weather of our past week in the Charlotte region and the rest of the Carolinas, in no particular order:

-- Charlotte's high temperature last Sunday was 75 degrees, which tied a record for the date and was about 25 degrees above the average high for that time of year. That came a day after we had a 73-degree high.

-- The weather turned cooler in Charlotte late in the week, but not to the south of us. On Thursday, while Charlotte dealt with a cold rain and temperatures in the upper 40s, it was nearly 80 degrees as close as Columbia and Florence (about 90 to 100 miles away).  Get in the car, drive 90 minutes, and switch from overcoat to shorts and T-shirts.

-- The warm front that divided winter and late spring on Thursday pushed south late in the afternoon. Temperatures fell from 78 degrees in Columbia to 50 degrees in three hours.

-- Mountain rainfall was excessive, and it certainly put a dent in drought conditions. Some totals I saw this morning included (for the past seven days): 12.18 inches at Wallace Gap, in Macon County in the western mountains; 9.33 inches at Highlands; 8.57 inches at Sylva; 7.39 inches at Elkville, in Wilkes County; 6.49 inches at Ararat, in Surry County; 4.99 inches at Healing Springs, in Davidson County; and 4.81 inches at Jacobs Fork, in Burke County.

-- Rainfall on Thursday from the strong low pressure system was 2.38 inches at Charlotte's airport. That set a record for the date.

-- Thursday's rain in Charlotte was the most since May 8 (2.41 inches). And Thursday's rain was 3 1/2 times the total for the entire month of November.

-- Shelby recorded 3.1 inches of rain Thursday. That was the most for the day anywhere in the United States.

-- There were numerous reports Thursday night in the area of thundersnow.  WCNC's Brad Panovich did a nice job in an Observer chat Thursday of explaining the phenomena. You need about 60 degrees' difference from ground temperature to the top of the cloud for a thunderstorm to form. That's not hard to find in summer. It is in winter. But on Thursday night, with air temperatures around 35 degrees, the extremely cold tops of clouds in the strong low pressure system were around minus-30 degrees.

What will next week bring?

Thursday, January 17, 2013

Thundersnow from a potent little storm

The low pressure system that will be responsible for heavy rain and snow today and tonight across the Charlotte region is not your typical winter storm.

This is an unusual system that has fascinated weather fanatics and meteorologists -- the kind of storm we don't see very often.

It is expected to produce thundersnow, and precipitation falling at extremely heavy rates.

Any other winter system that crossed our region with snow, ground temperatures around 50 degrees, and air temperatures around freezing wouldn't be a threat to drop accumulating snow. It would melt on its way to the ground, or quickly when it touched ground.

But this storm is different.

It is very strong, not very big, and will be moving quickly.  It is strong enough to create its old cold weather, actually.

As I've written before, this column is not aimed at meteorologists, but at people who are fascinated by weather. So I won't go into deep detail. But suffice to say there will be a lot of vertical lift in the clouds.

As WCNC-TV meteorologist Brad Panovich noted earlier today, it takes a difference of about 60 degrees between ground and upper level of clouds for a thunderstorm. That's not hard to get in summer, but it's unusual in winter. Ground temperatures will be near 35 degrees, but the very cold air aloft in this strong system will have readings about 20 to 30 degrees below zero.

When that happens, precipitation falls at very rapid rates.

Heavy rain is likely this afternoon and early this evening across the area. And as the center of the system crosses the area, temperatures will tumble, and the very cold air at the top of the cloud columns will be sent to the ground. That will help saturate the air with cold temperatures, enabling snow to reach the ground.

If the snow falls heavily enough, it will overcome the relatively warm ground temperatures and accumulate. Obviously, the process will be helped in places where ground temperatures are cooler (such as the mountains). But if it snows really hard in the Piedmont, those places could get a quick 2, 3 or even 4 inches of snow.

A similar storm hit the area March 1-2, 2009. Heavy rain fell that Sunday afternoon in Charlotte, and the rain changed to snow about 7 p.m. that day. Between 1 and 2 inches accumulated.

But a deformation zone -- one of those areas of heaviest precipitation -- formed in a corridor from Gaffney, S.C., to west of Gastonia. Strangely, that zone was right along Interstate 85. Snow fell at a rate of 2 to 3 inches an hour, and between 8 and 12 inches accumulated. Cars and trucks were stranded on the interstate highway overnight.

Will that happen again tonight?  Possibly, somewhere.

Either way, this is an interesting storm to watch.

Something I forgot ... There are some absolutely amazing temperature contrasts today in the Carolinas.  While we're talking about a snowstorm in North Carolina, on the other side of a warm front stretched across South Carolina, it's like April.

Can you believe that the 3 p.m. temperature in Columbia, just 90 minutes away, is 78 degrees! And it's 81 degrees in Kingstree, S.C., about halfway between Columbia and the coast. Or try 78 degrees in Florence.

Wednesday, January 16, 2013

Waiting for cold air? It's coming next week

The mountains are likely to get a full dose of wintry weather Thursday afternoon and evening, with heavy snow expected to fall for several hours.

That's great news for the ski resort operators and their customers, as the 3 to 6 inches of snow will set the stage for a fun weekend. It's certainly welcome news to those folks, especially after last weekend's spring-like conditions.

Lower elevations, such as Charlotte, will get rain from Thursday's storm, although we'll be seeing a brief shot of winter-like weather next week.

After the storm passes Thursday, it looks like we'll have generally dry and seasonal conditions Friday through Sunday, with highs in the upper 40s Friday and the mid 50s Saturday and Sunday. But a pair of cold fronts will cross the region late Sunday and Monday, and when all that has been completed, an arctic air mass will be the controlling factor in our weather.

Despite full sunshine, we'll be lucky to reach 40 degrees Tuesday afternoon in Charlotte. Morning lows Tuesday might be in the teens.

It'll be cold (mid 40s) again Wednesday, but it appears as if the cold air will be a short-lived event.  High temperatures are forecast to be back in the mid 50s Thursday and Friday.

Meteorologists have been talking for weeks about sudden stratospheric warming at the north polar region, and the eventual displacement of bitterly cold air into Canada and the United States. Some of that very cold air has arrived in the United States, but it's been bottled in the northern part of the country.

When the cold air has tried to poke into the Southeast, it's been short-lived.  Looking ahead into early February, it looks like that pattern will continue.  That doesn't mean we can't get snow, sleet or freezing rain. The storm responsible for mountain snow Thursday will be working with only marginally cold air. But the short-lived cold air intrusions are good news to those who don't like winter.

Tuesday, January 15, 2013

Fog, crazy temperatures, talk of snow ...

Sorry for being away a few days.  A little virus caught me last weekend and sent me to the hospital briefly, but it's time to get caught up here.

There is a lot of weather news out there, and I'll try to address it all briefly:

"SNOW" TALK ... A storm system is expected to cross the Southeast on Thursday and Thursday night, with temperatures marginally close to the snow level in parts of the Carolinas, Tennessee and Georgia.

Most of the computer models show this as a rain event for Charlotte, and the National Weather Service and most meteorologists are buying that solution. There'll be plenty of precipitation -- around 1 to 2 inches in parts of the Piedmont and foothills -- but temperatures simply aren't cold enough for snow.

Those who are wish-casting for snow say the low pressure system could strengthen enough to cool the atmosphere in the areas of heaviest precipitation, and that's certainly not out of the realm of possibility. But the computers simply don't show the system getting strong enough to do that.

Having said all that, stay tuned to the forecast.  And snow certainly is likely in the mountains, especially above 3,000 feet.  Finally, the exact track of the system will play a role in where the heaviest precipitation falls.

THE FOG ... It's dense again this evening, and that's a sign of a stalled front nearby. Remember those 70-degree temperatures we had over the weekend?  If you live 40 to 50 miles south of Charlotte, you're still enjoying the warmth. A cold air wedge became established during the daytime hours Tuesday, stretching generally east-west across South Carolina.

At 9 p.m., it was 48 degrees in Charlotte but 61 in Camden, S.C. -- and even warmer, 70 degrees, in Columbia.

It's a safe bet that the fog will continue throughout the night in the immediate Charlotte area, but it's not so clear what happens Wednesday. The forecast is for the cold air wedge to break down, and temperatures to climb into the mid 60s in Charlotte.  But these wedge conditions almost always are much, much more stubborn than expected.  Don't be surprised if we remain in the low to mid 50s much of the day, with low clouds.

TEMPERATURE PLUNGE ... The much-ballyhooed (by the computer models, for weeks) arrival of polar air now seems to be more likely, early next week.  A pair of cold fronts are predicted to cross the Charlotte region Sunday and Monday, and high temperatures Tuesday might struggle to climb much above 40 degrees, despite plenty of sunshine.

Will it be a transient (i.e., short-lived) shot of cold air, or will the polar outbreak last a while?  That's still an open question, but it looks like the end of January and beginning of February will be quite a bit chillier than the past several days, at least.

Friday, January 11, 2013

No winter here ... but look elsewhere

While we in the Charlotte region prepare for a weekend of 70-degree-plus temperatures and wonder whether the really cold air poised to drop southward will ever reach the Southeast, there is no lack of winter in other places.

A blizzard is taking aim at the Rockies and upper Midwest, and the northwest flow behind that storm will bring the coldest air in two years to California and Arizona this weekend.

Meanwhile, a blizzard is paralyzing Newfoundland, with some amazing snowfall totals and winds that are knocking out power to thousands of customers.

COLD AIR MOVING SOUTH ... Meteorologists have been watching the big mass of cold air for days, and now it appears to be moving toward the lower 48 United States.  We've written earlier this week about Sudden Stratospheric Warming, and how that condition will dislodge polar air southward (except we're not exactly sure how much of it is pushed onto our side of the globe).

By early next week, temperatures are expected to tumble about 40 degrees in the Rockies, Midwest and northern Great Lakes.

BLIZZARD ... The storm began taking shape Friday morning, dumping heavy snow in much of Idaho and in places like Salt Lake City. Winds gusted to near 80 mph in parts of Colorado. That storm is predicted to produce blizzard conditions this weekend as it treks on a northeast course out of the Rockies. Montana, the Dakota and northwest parts of Nebraska and Minnesota will get heavy snow and strong winds before the storm moves into Canada.

WEST COAST COLD ... Behind the storm system, very cold air will funnel into Oregon, California, Nevada and Arizona. Los Angeles will get lows in the mid 30s the next three nights, and it will be in the lower 30s near San Francisco. Light frost is predicted for the desert areas around Palm Springs, and there could be frost in the interior valleys.  It is not expected to be bad enough to damage crops.

Want some more cold.  How about upper 20s and a hard freeze in Phoenix on Saturday night?  And temperatures will reach the upper teens on the Arizona-Mexico border at night this weekend.

NEWFOUNDLAND STORM ... Much farther to the northeast, a separate storm system is crossing to the south of Canada's eastern-most province Friday.  That puts most of Newfoundland on the north (cold) side of the storm, and the precipitation is falling as snow.  Up to 30 inches of snow is possible in places, and winds are gusting above 60 mph.  Power is out across the province.

You can get some interesting Twitter accounts (including photos) of the storm https://twitter.com/search?q=%23snowmageddon.

Thursday, January 10, 2013

Our area -- surrounded by weather news

It looks as if the Charlotte region will be surrounded by big weather news over the next several days, while the computer models struggle to figure out how far south the arctic air will descend next week and beyond.

In the immediate future, we're in for some very warm weather -- except for Friday.

Temperatures are soaring well into the 60s today, but they'll be limited to the upper 50s by clouds and showers Friday, as a warm front slides northward across the region. But remember -- even the upper 50s are a lot milder than the average high of 50 degrees in Charlotte at this time of the year.

The three days after that, Saturday through Monday, will be downright silly with the mild weather. High temperatures will push into the lower 70s each day, and there'll be some sunshine accompanying the warmth Saturday and Sunday.

While all this is happening to us, areas near the Charlotte region will be dealing with big weather news.

Severe thunderstorms and tornadoes are threatening parts of the deep South today, and while the severe weather probably will weaken by Friday, there will still be a chance of flooding rains to our west. The heavy rain is expected to fall in Tennessee, Arkansas, Alabama, Mississippi, Louisiana, and maybe southern Kentucky.

A few showers are likely in our region, but what we get will pale in comparison with what falls to our west.

Meanwhile, to the northwest, bitter cold will be the story.

An outbreak of arctic air is forecast to plunge into the Rockies and upper Midwest by early in the weekend, and some of the temperature contrasts will be ridiculous. Fargo, N.D., is expected to have a high of 40 degrees today. That's downright tropical in January for North Dakota. But by Monday, the afternoon high is forecast to be 2 degrees.

Eventually, the cold air will reach the Carolinas. The best guess is that it arrives next Friday, but it's hard to tell how much cold air will actually move into the Southeast.

The computer models seem to hint at the coldest air being held north of the Carolinas. But I've seen posts on weather bulletin boards, noting that cold air -- which is heavy, dense -- sometimes spreads a lot farther south and east than the computers predict.  Given that a storm system could be moving across the Southeast late next week, we'll need to watch the temperature forecast closely.

Beyond that, who knows?

Consensus earlier this week was that a prolonged period of cold weather was headed for our region. Now a lot of the computer models are hedging on that, showing only a couple of short-lived cold snaps -- and nothing more than slightly-below-average temperatures (i.e., highs in the upper 40s) for late in the month.

Meteorologists have done a good job of determining the various players in our forecast, but the science of figuring out how those players interact is the tough part.

Tuesday, January 8, 2013

How warm will the Carolinas get?

Once a warm front pushes north of the Charlotte region sometime early Friday, we're in for several days of temperatures that are far above seasonal averages.

In fact, we could make a run at record highs this weekend, when temperatures are expected to climb above the 70-degree mark.

The warm front will spread plenty of clouds and some rain into the region from late Wednesday until early Friday, as it slowly moves northward across the Southeast. After that, we'll be under the influence of high pressure off the Southeast coast.

If skies were reasonably clear, it's possible temperatures Saturday through Monday could push well into the 70s. The all-time records are 75 degrees Saturday (set in 1890) and Sunday (1960), and 77 degrees Monday (1907).

But it looks as if there'll be considerable cloudiness those days, and possibly even a few showers. That could serve to put a lid on temperatures, holding them in the upper 60s.  Either way, it's a far cry from our average high of 51 degrees at this time of year.

The big difference will be at night.  As the National Weather Service office in Greer, S.C., noted, Tuesday morning probably will be the last time for a week -- at least -- that temperatures fall below freezing in Charlotte. Our morning lows this weekend might not drop below the 50-degree mark.  That certainly will help keep the heating bills in check.

It continues to look as if some really cold air will spill into the Southeast toward the end of next week, but the jury remains out, in terms of how long the cold will hang around. Any outbreaks of cold air will be doing battle with a stubborn high pressure ridge off the Southeast coast.

Monday, January 7, 2013

You like warm winters? Enjoy next 10-14 days

Those of you dreaming of arctic air and snow ... don't read this.

Today's entry is for those who moved to the Carolinas to escape 15-degree mornings, icy roads, and snow on the ground.  A warming trend is headed for the Southeast -- and, for that matter, for much of the eastern United States.

We could be looking at temperatures near 70 degrees by the end of the weekend.

We'll get there gradually. High temperatures today will only reach 50 degrees, but we'll have sunny skies, and that will make it seem nicer.  The sunshine continues Tuesday, with highs reaching 55 degrees.

By Wednesday, a warm front is expected to develop along the Gulf Coast and trudge northward. That will mean cloudy skies both Wednesday and Thursday. Highs on Wednesday could be near 60 degrees, but as the warm front moves through the area Thursday, daytime temperatures might be held back a bit by clouds, showers, and a northeast flow just to the north of the front -- in our area.

Then the milder air takes control Friday.  A ridge of high pressure is expected to set up shop in the Southeast, and it will serve to block the advance of any cold air for a while.

Forecast highs are low 60s Friday, then mid to upper 60s Saturday and Sunday.

Just for reference sake ... Charlotte's average high temperature at this time of year is around 50 degrees.

A cold front is expected to approach by late in the weekend, but the Southeast high pressure ridge will serve to weaken the front. That means a likely continuation of mild weather for much or maybe all of next week.

The long-range forecasts continue to point toward a much colder solution for the final 10 to 12 days of January.  A combination of conditions is forecast to push arctic air into the Rockies initially (by the weekend) and then gradually nudge the much colder temperatures farther to the south and east over a period of a week or so.

If all this verifies, we'll have colder conditions by around the 20th of January, and that could set the stage for a period of chilly weather.

How chilly?  It's too early to tell.  Between now and then, if you're a warm weather fan, just enjoy.

Friday, January 4, 2013

Mild next week, then winter returns

It looks as if we're in store for mild weather next week, but don't get too accustomed to it. Winter appears to be planning a return visit later in the month.

The computer models point to above-average temperatures across all but the Northeast next week, and that will translate into afternoon high temperatures well into the upper 50s and possibly the lower 60s by later in the week for the Charlotte region.

The warm-up will begin after a weak storm system crosses the area late Saturday and early Sunday. It dropped to 22 degrees at Charlotte-Douglas International Airport on Friday morning, and temperatures probably will be in the mid 20s again Saturday at daybreak.

Then comes a change to warmer conditions for all of next week.

After that, there are a bunch of signs pointing to some pretty cold weather returning to the United States and eventually making its way into the Southeast. The best guess among meteorologists is that the Southeast will see the cold weather arrive somewhere around the 16th to the 20th of the month.

A couple issues are at work here.  A number of meteorologists are pointing to sudden stratospheric warming in the arctic. That is a buildup of relatively warm air between 25,000 and 100,000 feet above the ground in the far north. Accu-Weather mentions this in a story today (http://www.accuweather.com/en/weather-news/nasty-cold-waves-could-be-in-t/3586088).

This condition tends to send cold air near the surface southward. About the same time, the North Atlantic Oscillation and Arctic Oscillation are forecast to be in a negative phase. That means the atmospheric pattern would steer weather systems into the central and eastern United States.

One possible fly in the ointment -- the persistent low pressure in the eastern Pacific. The atmospheric flow in the eastern Pacific has tended to block the southward movement of cold air so far this winter. If the Pacific Oscillation is negative, that could stop any arctic outbreaks from pushing very far south of the Midwest and Great Lakes.

The long-range computer models think the cold air will win out. Accu-Weather meteorologists predict the arctic air will move into the upper Midwest and Rockies initially, then keep pushing a little farther south and east. For a while, the Southeast will remain in the mild air, they predict.  Eventually, they say, arctic air will dominate.

WCNC's chief meteorologist, Brad Panovich, posted a GFS model forecast on his Facebook page yesterday that shows some really brutal cold in the Southeast later this month.

Some of you are saying, "We've heard this before," and you're right. Some meteorologists have been predicting a turn to much colder conditions since late November, and it hasn't happened.

In the meantime, enjoy the milder conditions next week. That seems almost certain to happen.

We'll have to wait and see what happens beyond that.

Thursday, January 3, 2013

2012 -- a year of no-shows

Want to know what kind of weather year 2012 was for the Charlotte region?

Two of the biggest stories of the year were things that did not happen.

Sure, there were a couple major events in the area, including a tornado inside the Charlotte city limits and a record-setting heat wave.

But for the most part, 2012 lacked major stories -- at least in the immediate region. Nationally, it was the year of a devastating drought in the central United States and a devastating hurricane/superstorm on the East Coast.

Among the biggest stories for Charlotte-area weather in the recently-ended year, though, were the Winter That Wasn't, and the Thunderstorm That Never Arrived.

Here's a look at the big regional stories -- including two national stories that had a local impact:

MARCH TORNADO ... This was a freak, of sorts.  A major outbreak of tornadoes occurred March 2 and 3, but a stationary front had been draped across the Carolinas border for much of March 2. Areas to the north of that front were in cooler, more stable air.  The National Weather Service had issued a tornado watch for areas south of the front.

But in the early-morning hours of March 3, a Saturday, a strong thunderstorm along or just north of the stationary front caused a tornado to form east of the city. The twister touched down near Reedy Creek Elementary School and carved a path into Cabarrus County. Although some meteorologists think the twister might have reached EF3 strength, the National Weather Service classified it as an EF2, with top sustained winds of 130 mph.

JANUARY TORNADO ... This one was really a freak storm. Tornadoes in mid-winter are a rarity, even in the South, although with last winter's mild temperatures, maybe it shouldn't have been surprising. Three tornadoes struck in Rutherford, Burke and Catawba counties, causing about 20 injuries and damaging or destroying about 100 residences.

THE WINTER THAT WASN'T ... It was one of the mildest winters in history, and if not for a brief period of sleet on the evening of Feb. 19, Charlotte might have gone without even a trace of frozen precipitation for the first time since records starting being kept in 1878.

Various atmospheric patterns collaborated to keep temperatures mild in the east. In January, Charlotte's highs reached 60 degrees or warmer on 12 days.  There were four 70-degree-plus days in February. Spring started the same way, as March (the first month of meteorological spring) had 10 days in the 70s and 10 more in the 80s. In fact, it was the second-warmest March in Charlotte history.

STORMY AND STEAMY ... May, July and August were hot, humid, and stormy.  Charlotte recorded nearly 6 inches of rain in May, and there were much-higher totals in some parts of the area -- thanks to numerous thunderstorms. At Charlotte-Douglas International Airport, there were storms on nine days in May; 16 in July; and nine in August.  June was a dry month.

Some parts of the Charlotte region recorded nearly 20 inches of rain from early May to early September. It was welcome, especially considering how dry the last few months of the year turned out.

JULY 4 HEAT WAVE ... For three straight days -- June 29, June 30 and July 1 -- the official high in Charlotte was 104 degrees. That equaled the city's record high temperature, and there were readings of 106 and 107 degrees in the region. The high also reached 100 degrees on July 5 and 8. Air conditioning technicians were working around the clock to keep up with the demand for repairs.

The heat finally broke on July 9. It turned out to be the fifth-hottest July in Charlotte history.

WESTERN WILDFIRES ... While this did not directly affect Charlotte, there was an indirect connection. A C-130 plane from a Charlotte-based Air National Guard unit crashed July 1 while fighting a wildfire in South Dakota's Black Hills. Four of the six crew members were killed. An investigation later determined that the plane encountered severe turbulence and was caught in a downdraft.

THE THUNDERSTORM THAT NEVER ARRIVED ... Never has a busted local forecast had such a big impact nationally. The stormy pattern that had been persistent in Charlotte during the summer continued into late August, for the start of the Democratic National Convention in the city.

Strong storms hit on the Saturday, Monday and Tuesday of the DNC (Sept. 1, 3 and 4), with more than 2 inches of rain falling. Some flooding was reported in the Saturday storm.

President Obama was scheduled to deliver his acceptance speech outdoors on Sept. 6 at Bank of America Stadium, and many of those who had volunteered their time to help with the convention were promised a ticket at the event. Unfortunately, meteorologists predicted another day of stormy weather on the 6th, with a cold front forecast to move through the region.

On the 5th, Democratic Party officials scrubbed plans for an outdoor speech and moved the event indoors to Time-Warner Cable Arena.  Naturally, most of Sept. 6 was dry and sunny.

SANDY ... The Charlotte area escaped any direct impact from the hurricane-turned-superstorm. But North Carolina took a shot from Sandy in two different ways. As the hurricane chugged up the coast, closer to shore than originally expected, strong winds and high waves tore up roadways and houses along the Outer Banks. And once the storm moved inland, its back-side precipitation brought heavy snow to the North Carolina mountains. Ski resorts were able to open at the beginning of November.