Monday, December 31, 2012

After one month of winter ...

The first month of meteorological winter is nearly at an end, and if one trend has developed, it's been the lack of truly cold air in the Southeast.

Most meteorologists point to persistent low pressure over the Pacific Ocean, off the western coast of the United States, as the dominant player in our weather for December.  The counter-clockwise flow around the low has blocked the intrusion of polar air into the Southeast.

First, let's get the whole winter definition thing straight.  Meteorologists define winter as being from Dec. 1 through Feb. 28 -- or about three weeks ahead of the traditional definition of the season.

December 2012 will be among the 15 warmest in the 137 years of record-keeping in Charlotte. The average temperature will be about 6.7 degrees above the norm. There were nine days when the high was 65 degrees or warmer.

The final part of the month was cooler, but the chilly weather recently came far short of negating what happened earlier in the month.

For those hoping a winter storm would arrive in Charlotte, December has been a bust.

The month started dry, continuing a trend that began in September and created severe drought conditions in most of the Charlotte region. But over the last half of the month, the storm track has been pushed to the south, and a steady stream of low pressure systems has crossed the Carolinas.

For the first time since September, we're experiencing above-average rainfall for the month.

What's ahead?

Most of the long-range meteorologists I've read are predicting mild weather through the first two-thirds of January.  It's possible a renegade winter system could develop, possibly in a cold-air damming situation, but if the experts are to be believed, it will be at least the 20th of the month before cold air arrives in the Carolinas. And there's really no guarantee it'll come then.

One warning ... long-range forecasts come with plenty of shortcomings. After all, we heard predictions of polar outbreaks in the Charlotte region in early December and again around Christmas.  It didn't happen.

Meteorologists say the forecasts of five to seven days are a lot more reliable.  For now, we're looking at a continuation of the recent trend -- temperatures at, or slightly below, seasonal averages; and precipitation every three days or so.

Monday, December 24, 2012

Big storm looms for Christmas night, Dec. 26

A major storm system appears likely to bring a wide variety of bad weather to the central and eastern United States on Christmas night and Wednesday.

The Carolinas might escape the worst of the system, instead getting what we need most -- lots of rain.

But strong winds behind the storm system could be a problem, and we're still not clear from the threat of severe weather Wednesday.

The storm is expected to bring heavy snow and blizzard conditions to parts of the Midwest and Great Lakes, and an outbreak of severe thunderstorms and tornadoes is possible in the Deep South.

This is not what holiday travelers need, and it might be best for anyone planning to hit the road to consider waiting a day -- or leaving a day earlier.

In an effort to make some sense from this storm, I'll break this into three categories -- winter weather, severe weather, and the Carolinas.

WINTER WEATHER -- Areas north and northwest of the low pressure's center will get the heavy snow and blizzard conditions.

As of now, meteorologists expect the storm to cross the Rockies, move over the Midwest (somewhere near St. Louis), then push eastward along the Ohio River before making a rather northeast turn over Indiana and central Ohio.

Snow likely will hit the Rockies late Christmas Eve and early Christmas Day, and it will reach the Mississippi River area later Christmas Day. Snowfall will come Wednesday over southern Illinois, central Indiana and Ohio.

As of now (and this is subject to change), cities that stand a chance of getting heavy snow include St. Louis, Indianapolis, Detroit and Cleveland.  People in places on the edge of the heavy snow band -- Chicago, Milwaukee, Cincinnati, Louisville and Pittsburgh -- show pay close attention to forecasts over the next 36 hours.

SEVERE WEATHER -- We could be looking at a tornado outbreak on Christmas Day. The Storm Prediction Center in Norman, Okla., has issued a "moderate" risk of severe storms and tornadoes on Christmas from central and northern Louisiana eastward across central Mississippi and Alabama.

On Wednesday, the threat moves eastward into the Carolinas and northern Florida. The area from Charlotte eastward is included in the risk of severe thunderstorms.

CAROLINAS WEATHER -- Rain likely will spread into the Charlotte region by Christmas evening or night. Then forecasters expect milder air to blow into the area overnight. That will make the atmosphere unstable, and when a cold front being dragged by the big storm system moves across the Carolinas during the day Wednesday, severe weather is possible.

Rainfall could total 1 to 2 inches across the region.

The other threat will be post-frontal wind. A strong circulation around the low pressure system will bring gusty northwest winds into the Charlotte region Wednesday night and early Thursday. That, combined with all the rain, could topple trees and cause power outages.

After weeks, even months, of calm weather, we're about to get a stormy 36-hour period across the region.

Friday, December 21, 2012

Snow ... it was a long time coming

Heavy snow was falling Friday afternoon in the typical lake-effect areas, where northwest and west winds were delivering a steady flow of cold, unstable air.

That included North Carolina's mountains, where Beech Mountain picked up 3 to 5 inches since around daybreak. At midday, there were numerous reports of 1 to 3 inches on the ground in the high country, and that's certainly good news to the ski resort operators.

It's also enough to bring a smile to those who were looking for a White Christmas in the mountains.

It also was snowing hard in the places where northwest flow typically does its thing -- near Buffalo; east of Cleveland, on the Michigan side of Lake Michigan; in the Pennsylvania and West Virginia mountains; and, of course, in upstate New York south of Lake Ontario.

That comes on the heels of the heavy snow that fell late Wednesday and Thursday across Iowa, Wisconsin and parts of northwest Illinois.

I saw some amazing numbers, that tell a lot more about last winter than this season.

Last winter, of course, was among the mildest on record in much of the eastern United States. Charlotte's total snowfall was a trace, and it all fell in a one-hour period -- in the form of sleet -- on a Sunday evening in February.

It was the same story in the Great Lakes, the Midwest, and on the East Coast.  And the early part of this year has continued the trend.  It was colder than average in November, but little or no snow fell.

So when snow finally came down Thursday in Chicago, it marked the time in 290 days that the white stuff fell in the Windy City. Cleveland got snow Friday -- also the first time in 290 days.

Those are among the longest periods in history without snow.

Long-range trends point toward colder-than-average temperatures in January, so I think we can expect that snowfall will come with much more frequency now.

Tuesday, December 18, 2012

Weather Service eyes change in warnings

The National Weather Service is launching a three-month test on changes in the wording of its winter weather advisories and warnings.

The test is the result of a study showing that some people are confused by exactly what is meant by a Winter Weather Advisory, Winter Storm Watch, and Winter Storm Warning.

The goal is to make the headlines a bit clearer, so people get an idea of what type of winter weather threat is possible, and when it might happen.

Basically, a Winter Weather Advisory is issued when relatively minor amounts of snow, ice or sleet are expected. In an advisory situation, we're told that the wintry precipitation will be a nuisance, but not enough to cause a major problem.

The Winter Storm Watch is much like a Tornado Watch or a Hurricane Watch.  It's notification that a potentially significant winter storm is possible, although meteorologists aren't certain enough to issue a warning.

And the Winter Storm Warning is used when a significant amount of snow, sleet and/or freezing rain is expected in an area soon.

Here are some examples of how it would change.

For advisories ...

Current: "The National Weather Service has issued a Winter Weather Advisory for snow."

Change: "The National Weather Service advises caution for light snow."

For watches ...

Current: The National Weather Service has issued a Winter Storm Watch."

Change: The National Weather Service forecasts the potential for heavy snow."

For warnings ...

Current: The National Weather Service has issued a Winter Storm Warning."

Change: The National Weather Service has issued a warning for a dangerous snow and sleet storm."

The experiment will take place until March 31 at 26 National Weather Service offices across the country. The Charlotte region is served by four offices.  Greer (S.C.) oversees Charlotte and most other area counties. Raleigh oversees Anson, Richmond, Stanly and Montgomery counties in the Charlotte region. Columbia handles Lancaster and Chesterfield counties in our area. And the Blacksburg (Va.) office oversees Watauga, Ashe and Wilkes counties in the Charlotte region.

Blacksburg is the only Charlotte-area office asked to participate in the experiment this winter.

But if the Weather Service likes what it sees, we all could be getting our winter weather advisories, watches and warnings a new way next year.

Monday, December 17, 2012

Between now and the Belk Bowl ...

We're in for a little of everything over the next 10 days, but the overall trend will be from mild to chilly, and there's even some wintry precipitation in the forecast for some of us, probably.

Many people will be traveling this weekend, in advance of the Christmas holiday, and there'll be additional activities next week, including the Belk Bowl football game Dec. 27 in Charlotte.

It looks as if we'll see three rain episodes -- today, Thursday, and Dec. 26 or 27 (that might be more than rain ... we'll deal with that later).  Temperatures will be above average the next four days, then dip gradually and finish below-average by Christmas week.

Let's break it into five parts:

TODAY ... We got some much-needed rainfall Sunday evening and overnight, with many areas receiving a half-inch or more.  There was .58 of an inch in my rain gauge, as of daybreak Monday. Another area of rain will move into the area around midday and continue into this evening.  Overall precipitation totals could be an inch for many people in the Charlotte region.

Temperatures will probably remain in the upper 50s for the rest of the afternoon.

TUESDAY-WEDNESDAY ... This will be one of the quiet periods. Mild Pacific high pressure will dominate the region, with sunny to partly cloudy skies much of the time. Temperatures will be well above average (53 is the average high), climbing into the low 60s Tuesday and the mid 60s Wednesday.

THURSDAY ... A strong cold front will advance on the region. It'll cloud up Thursday, with showers arriving by afternoon. Temperatures will reach about 60 degrees, but it'll be the last mild day for a stretch.

FRIDAY-CHRISTMAS ... Colder air will filter into the Carolinas on Friday. There's a good chance for a northwest-flow snow event in the mountains Friday, with a fetch of cold, unstable air being carried to the Tennessee-North Carolina border from the Great Lakes. That could produce a couple inches of snow in the mountains -- just in time for Christmas.

Down here in the lower elevations, high temperatures will only reach 50 degrees Friday (a gusty breeze will make it seem colder), and then the lower 50s Saturday and Sunday. But it'll be sunny, and those temperatures are average for this time of year.

Incidentally, that cold front will bring strong winds and some heavy snow to parts of the Midwest and Great Lakes. If you're planning travel in that direction late this week, you could have problems.

Gradually cooler air will push into our region Christmas Eve and Christmas Day, but a continuation of dry weather is expected. As of now, look for highs in in the upper 40s for Christmas Eve and the low to mid 40s on Christmas Day. It'll be a chilly Christmas.

DEC. 26-27 ... This is where it gets tricky.  The consensus is that a storm system will cross the central and eastern United States.  But the details are unclear.

Certainly, cold air will be in place across the East, and precipitation will be snow somewhere in the Midwest and Great Lakes.  The best bet for the Carolinas, at least in the lower elevations, is for a chilly rain event.

But if cold air damming were to establish itself -- which would happen if strong high pressure were parked in New England on Dec. 26 -- then freezing rain would be a possibility in parts of the Carolinas.

For now, the computer models seem to be indicating temperatures will be in the 40s in the Charlotte region during the precipitation. But we'll be watching this.

Friday, December 14, 2012

Much colder ... in time for Christmas

We've been talking for so long about a possible change to more wintry conditions in the Carolinas, and it looks more than ever as if a big cool down is coming in time for Christmas.

The computer models are in agreement that a shot of arctic air will push into the eastern United States next weekend and hang around through Christmas.

For now, it looks like dry cold -- i.e., no snow or ice.  But with temperatures that cold, even a minor disturbance zipping across the Carolinas could bring a little holiday excitement.

The National Weather Service office in Greer, S.C., is hinting at the change in its latest forecast, predicting a high in the upper 40s next Friday. Its forecast range is seven days, so it'll be interesting to see what the prediction for next Saturday (Dec. 22) is.

If some of the forecasts verify, we could be in for a few days when high temperatures struggle to hit 40 degrees and morning lows are in the teens. That would be around Christmas.

Before all that happens, we're finally looking at a chance of measurable rain on Sunday and Monday. The heaviest precipitation is expected across Georgia and western South Carolina, but the computer models paint a swath of a half-inch to three-quarters of an inch in much of the Charlotte region.

We'll update this Christmas forecast over the weekend.  With many people hitting the road for holiday visits, the weather will be a big issue.

Thursday, December 13, 2012

Something to watch tonight: Meteor shower

We've been talking for days about possible storms and possible outbreaks of polar air.

Today let's talk about something that's certain to happen -- a meteor shower.

It's the Geminid meteor shower, an annual December event, and astronomers say the peak viewing will be tonight. This year's shower could be better than usual.

That's because the moon is in a new phase, which means there won't be any moonlight to distract from the sight of meteors zipping into the Earth's atmosphere.

The meteors are fragments of an asteroid, and astronomers say there could be 50 to 100 per hour at times overnight.

You'll be able to see them from about 9 p.m. until dawn. They'll be soaring across the sky, but they seem to originate from the constellation Gemini the Twins. That is above and a bit to the left of Sirius, one of the brightest lights in the nighttime sky.

At 9 p.m., Gemini will be rather low in the east-northeast sky. By 2 a.m., when the meteor shower will be at its peak, Gemini will be almost overhead.  It should be quite a show.

One warning ... dress for the weather.  Tonight will be the coldest night in Charlotte for about two weeks, with lows in the upper 20s by Friday morning.

You also might want to check out a Web chat sponsored tonight by scientists at NASA's Marshall Space Center. You can find it at

Wednesday, December 12, 2012

Storms, and rumors of storms

We've been waiting for weeks to see a change in the weather pattern across the United States, especially the Southeast.

For several weeks, the weather generally has been warm and dry, with only a few exceptions. The storm track, for the most part, has been to our north, which means we've missed out on the significant rainfall. And when it does rain, as is happening today, the precipitation is much lighter than what we need, to put a dent in our big rainfall deficit.

(By the way ... at 2:15 p.m., there seem to be some radar returns that indicate a few sleet pellets might mix with the rain. But any sleet will be transitory. Today's system is a rain-maker.)

What is expected, at some point, is for the storm track to be pushed farther south, so that low pressure systems cross some part of the Southeast; and for polar air to break free in Alaska and move southward into the continental United States.

There's no definitive sign from the computer models of a major cool down in the Southeast anytime soon, although it appears as if our above-average temperatures will fall back to average levels -- and maybe a few degrees below average -- by the middle of next week.

The storm track also is a question mark.

One major system is expected to sweep across the country this weekend, but that storm is expected to run across the Great Lakes.  The next low pressure system is expected around the middle of next week. Some computer models show that storm crossing the Southeast and bringing the potential of heavy precipitation, but the recent runs have been trending farther north -- once again, keeping the much-needed rain away from us.

Now the talk is about a system that could develop in the Dec. 22-24 time frame, with a storm coming off the Pacific Ocean, sweeping across the Southwest, and then moving across the country -- just in time to make a mess of holiday travel.

Once again, the big question for us in the Carolinas is what path the storm will follow after it exits the Southwest. Will it move into the Gulf of Mexico and then come across the Southeast?  Or will it curve northeast, and move up the Ohio Valley or across the Great Lakes?

Either way, it seems as if we're moving into a stormier pattern, much as had been expected for the second half of December.

Friday, December 7, 2012

The real story -- drought

If this were June, we'd be in a state of panic across the Carolinas.

We'd be complaining about brown, dried-out lawns, and crops withering in the fields. We'd worry about lake water levels plummeting in the midst of summer heat.

Fortunately, our current drought has arrived in late autumn and early winter, so it's not quite the story it might be in summer.

But make no mistake about it. We're in a drought.

State officials said Thursday that Mecklenburg and surrounding counties are in a Moderate Drought, the lowest level of drought. In all, 65 counties have drought conditions, which is up from 54 a week ago. We're coming off one of our driest Novembers ever, and October also was bone-dry.

December has started the same way.

"Although we still haven't had any reports of public water supplies being affected, we are seeing impacts to streams, groundwater levels, and inflows to reservoirs," Tom Reeder, director of the N.C. Division of Water Resources, said Thursday.

Autumn typically is a very dry time of year in the Carolinas, but this fall has been extraordinarily dry. The storm track has been pushed well to the north of the region, and when a storm system moved up the East Coast, it was too far east to bring rain to the Charlotte region.

When will things change?  Who knows?

Meteorologists initially predicted El Nino conditions this winter. That would have increased the rainfall chances for the Southeast.  But now the El Nino forecast has disappeared, and we'll have what's called a "neutral" winter.

The computer models offer little or no help.  In late November, some of the models predicted a change to cold and stormy conditions in early December.  Instead, it was unseasonably warm and dry.

I wrote two days ago about the latest predictions, of a change to wet and much colder weather after the middle of the month.  But in the world of weather, the saying is, "The trend is your friend." It's been dry, so until we see a change, we can expect more of the same.

A cold front will bring us a chance of showers and thunderstorms later Monday, but that won't cure our ills. Rainfall in Charlotte this year is more than 9 inches below seasonal averages. One cold front won't make up for that.

Wednesday, December 5, 2012

Big change coming for mid/late December?

Weather bulletin boards have been abuzz for several days with discussions about a major change in the weather pattern coming later this month for the central and eastern United States, including the Southeast.

This could have major ramifications on a lot of people's travel plans over the Christmas and New Years holidays.

The consensus seems to be that two changes are headed our way:

-- Wetter conditions, which seems rather likely.

-- Colder weather, which is not quite a certain bet.

The computer models, for the most part, show a shift in the pattern at higher latitudes (i.e., Alaska, Canada, Greenland, northern Europe) that would allow much colder air to slide southward into the United States. Some of the models have been inconsistent on the details, but it seems likely that the colder air will at least reach the northern half of the country.

That, in turn, will push the storm track -- which has been north of the Carolinas -- a lot farther south. We could see a hint of that next week, with wetter conditions in parts of the Southeast.

Eventually, the thinking goes (at least for some meteorologists), colder air will seep even farther south. Add that to a much wetter pattern, and you have the chance of cold rain or frozen precipitation in parts of the south.

When will this happen?  The consensus seems to be somewhere around Dec. 20, just before Christmas.

My brother Michael, who I've written about before, has been harping about this to me for several days. He's much better at interpreting the models, and Michael insists a colder and stormy pattern will descend into the central and eastern part of the country as December progresses.  I'll take his word.  He correctly predicted the major pattern shift in mid-February 2011, when the Southeast turned balmy after 2 1/2 frigid months, and last winter's very mild conditions.

Some signs point to the eventual arrival of cold air in the Southeast. There's a negative North Atlantic Oscillation and Arctic Oscillation, and the computer models show signs of high pressure building in Alaska. Those are conditions that mean cold in the eastern United States.

But there also is a persistent trough in the Pacific, which has blocked the southward movement of cold air. 

I suspect this is a topic we'll be following closely over the next 10 to 14 days.

Tuesday, December 4, 2012

10 years ago ... coated in ice

Ten years ago today, the Charlotte region awoke to the sounds of cracks and crashes.

It was a symphony of tree limbs and trees crashing onto roofs, cars and the ice-covered ground, in the wake of the worst ice storm in decades.

The ice storm of Dec. 4-5, 2002, left millions of Carolinas residents without power, some of them for many days in winter cold. It caused at least three deaths, changed the region's tree scape permanently in places, and served as a reminder that ice -- not snow -- is the big winter danger in the region.

A cold front ushered in arctic air a few days before the storm, bringing unseasonably cold temperatures into the Carolinas. Then a low pressure system formed over the lower Mississippi Valley and moved eastward.

The area from York County northeast to Raleigh was locked in a cold air wedge. Chilly air was funneled into the Piedmont from a high pressure system parked over New England. Precipitation from the low pressure system moved into that pocket of cold air.

Farther to the north, in Virginia, the temperatures in the atmosphere -- from higher levels to the ground -- were below freezing. So the precipitation fell as all snow, dumping 1 to 2 feet along the Interstate 81 corridor.

But in the Piedmont, a pocket of above-freezing temperatures a short distance above the ground melted the snow as it fell, turning it to rain. Temperatures at the surface were below freezing, however. So when the rain hit the ground, it froze.

Freezing rain is not uncommon in the Piedmont, but the amount of rain that fell in the December 2002 storm was heavy enough to cause buildups of 1 inch of ice in many places.  Meteorologists say that accumulations of a half-inch or more are enough to cause trouble.

The December 2002 storm caused plenty of trouble.

The storm broke a record for Duke Energy power outages in the Carolinas -- 1.375 million customers left without electricity. Other companies across the Piedmont were similarly hit.

In comparison, about 700,000 outages were reported in a December 2005 ice storm that hit the western Carolinas and northeast Georgia. Hurricane Hugo caused 696,000 power outages.

Across the Charlotte region on the morning of Dec. 5, 2002, trees and tree limbs fell.

Road conditions weren't bad.  For the most part, the streets were wet. But power was out almost everywhere.

A number of people made the mistake of trying to heat their homes with charcoal grills. More than 250 carbon monoxide cases were reported across the region on the first day of the storm.

Don McSween, Charlotte's city arborist, said 30 percent of the oak trees were damaged.

Charlotte-Mecklenburg police reported burglaries increased 54 percent during the five days after the storm, as crooks took advantage of homes where residents had left, seeking shelter in hotels or with friends fortunate enough to have electricity and heat.

Duke Energy paid $87 million to repair the damage, including $56.5 million to pay for outside labor -- repair crews who came from across the eastern United States to help restore power.

The Rev. Brad Busiek, pastor at Newell Presbyterian Church, had arrived from Texas a few months before the ice storm. On the Sunday after the storm (Dec. 8), Busiek began his homily with a variation of a familiar poem: "Twas the ice before Christmas, when all through the house, everyone was shivering, especially my spouse."

At St. John Neumann Catholic Church in east Charlotte on that Sunday morning, there was a moment that almost seemed miraculous. In the middle of Mass, being celebrated in candlelight, the power came back on.

What would be different if such a storm hit today?

Duke Energy, which received generally good grades from the N.C. Utilities Commission in a post-storm study, has changed some its policies. One of those includes a beefed-up database for keeping track of power outages. That system has been helpful in storms since 2002, company officials say.

Duke's staff of meteorologists also earned praise, for correctly predicting that significant ice damage was likely in the Piedmont. That allowed the company to position its repair crews properly. In the wake of Hurricane Hugo, Duke Energy restored power to an average of 38,667 customers a day. After the ice storm, that daily average was 152,777.

The arrival of smart phones and other hand-held devices would create a different scenario today, especially in distributing information. In 2002, if the power was out, so were people's computers, for the most part. Today, residents could get news from their phones and other "smart" devices, without the need for electricity.

As was the case with Hurricane Hugo, we can hope that the December 2002 ice storm was a once-in-a-lifetime event.

Photo: Dec. 4, 2002 in Winston-Salem.  From left, Darren Richards, Trayshawn Davis and Jasmine Carter, play in the snow. Winston-Salem Journal, David Sandler