Toasty forecast for early December

I know people who want cold temperatures during the weeks leading up to Christmas. They say it gets them in the holiday spirit.

I also know people who have been shivering this month and are not happy about November's cold weather.

Here is some pleasant news for the latter group:  The first part of December will be warmer, according to just about every long-range forecast.

The change to milder weather is likely to start at the end of this weekend and early next week, when the overall atmospheric pattern across the United States changes to a zonal flow.  Instead of the huge kink in the jet stream that sent arctic air cruising southward into the United States in recent weeks, we'll be looking at more of a west-to-east flow of weather systems.

That means warmer temperatures.

The polar vortex will intensify at the North Pole, which will bring the frigid air back to the far north. And that will allow milder air from the Pacific Ocean to dominate weather across the United States.

The best guess from meteorologists is that temperatures will run somewhere in the ballpark of 4 to 6 degrees above average for the first two weeks of December. Normal highs and lows in Charlotte at that time of year are around 55 and 34 degrees.

This month is likely to finish among the 10 coldest Novembers on record in Charlotte. As of Sunday, the average temperature in the city was 5.3 degrees below seasonal norms.  That deficit decreased with Monday's mild weather, but it will build again with chillier conditions returning for the rest of the week.

That means your heating bills will be a lot higher than usual for November.

How long will the mild trend last?

The long-range forecasts for December show question marks after the first two weeks of the month. Meteorologists who specialize in seasonal forecasts have said that December and early January are likely to be changeable, before a cold snap arrives in the latter half of January and into February.

Problems ahead for big Thanksgiving travel day?

A few days ago, we were giving Thanksgiving travelers the all-clear signal for Tuesday and Wednesday. Now that outlook isn't so rosy.

Both the Europeans and Global computer models are predicting the development of a low pressure system along the Carolinas coast Wednesday, and that spells possible trouble for travelers.

"There definitely will be a coastal low," National Weather Service meteorologist Scott Krentz said Saturday evening. "The big question is how close to the coast it will be."

The closer to the coast, the farther inland for precipitation.

Wednesday is the biggest travel day of the year, and rain will make a mess of things for those flying or driving somewhere for Thanksgiving. Right now, it appears as if the biggest problems will be for anyone headed toward eastern North Carolina, including the Raleigh area, or up into central and eastern Virginia.

I must point out that temperatures will be chilly Wednesday, and although the precipitation almost certainly will fall as rain, some of the information being churned out by the computers says "snow," especially for northeastern North Carolina and farther to the west in the N.C. mountains.

I've traveled on a rainy Wednesday before Thanksgiving, and it was miserable.  A steady rain turned a trip up I-85 to Richmond into an ordeal.

We should have a better idea on the makeup of the storm, including its path, by later Sunday or early Monday.

But it's definitely a new -- and unwanted -- wrinkle in the Thanksgiving travel picture.

Good news for Thanksgiving?

It looks as if weather patterns across the eastern United States are shaping up nicely for Carolinas residents during the Thanksgiving holiday week.

Translated ... travelers apparently won't have to deal with big storms, and those who enjoy a winter-like feel to the air will get their wish on Thanksgiving Day.

If your preference is for shorts and T-shirts on Thanksgiving, sorry!

Thanksgiving week will be ushered in with a fairly significant storm system across the eastern United States. Low pressure will move up the Ohio Valley late Saturday and Sunday. A weak cold air damming event could develop in the Carolinas Piedmont and Foothills on Sunday, but it probably won't last long -- especially in the Piedmont.

That will set the stage for a rainy Sunday, with temperatures in the 60s.

By the way, the atmosphere will have one element needed for severe weather Sunday -- wind shear. But instability will be lacking, so we're probably looking at showery weather.

The showers will taper off Monday, and we'll be in a warm sector for the day before another cold front arrives. That means highs in the upper 60s and lower 70s.

The next cold front arrives Monday night, and it will be followed by another front later in the week. By Thanksgiving, we're probably looking at high temperatures in the low to mid 40s for Charlotte, with sub-freezing morning lows. But there are no signs of major storm systems, even for the weekend after Thanksgiving.

Incidentally, our warm-up Sunday and Monday will sweep into the North. Highs in the 60s are possible for New York and Philadelphia.  Places along the Great Lakes that were hit with heavy snow this week will see a rapid melt-off Sunday and Monday.

For Thanksgiving holiday travelers, the advance outlook is good.

"I don't see anything that will be a problem in the Southeast for travelers on Tuesday and Wednesday," said Chris Horne, of the National Weather Service office in Greer, S.C.

Cold? Absolutely! Record-breaking? No!

A lot is being made by weather watchers -- including me -- of the cold wave arriving in the Carolinas later Wednesday.

For several nights, we've watched national newscasts showing heavy snow and bitter cold in the Rockies and Midwest. Even Texas has gotten into the act, with temperatures taking a 40-degree nose dive.

Terms like "polar vortex" and "arctic blast" are being thrown around, and you'd almost think we were in the thick of winter.  That's not the case.

First, here are a couple things that the cold wave will do:

1. Last a while.  This pattern change will last at least two weeks, until around Thanksgiving. A couple reinforcing surges of cold air will push into the United States and reach the Southeast next week and early the following week.

2. Drop temperatures considerably.  We've been in the 70s for several days, and that will end after today.  Thursday will be a cross-over day, with highs in the 50s as colder air filters in. A secondary cold front will arrive later Thursday, dropping Friday's highs to the 40s.  That's a lot colder than anything we've had for a while, and it's well below the seasonal average high in Charlotte for this time of year -- 63 degrees.

3. Bring snow -- to parts of the North.  The traditional "lake-effect" snow areas around the Great Lakes will get a lot of snow from these various surges of cold air. We're talking about upstate New York (from Lake Ontario); the area from Cleveland's eastern suburbs to Buffalo (Lake Erie); Michigan's Upper Peninsula (Lake Superior); and the corridor from South Bend, Ind., up along western Michigan's shore (Lake Michigan).

But here are some things the cold wave is not:

1. A record-breaker.  A few records might be broken, but here's something to think about. The coldest morning low temperature in the first surge of cold air this weekend in Charlotte will be 24 or 25 degrees Saturday. The record low for Saturday is 20, set in 1969.

2. Unusual.  "The upcoming pattern will feature a trough in the eastern United States, and that's typical in winter," said John Tomko, of the Weather Service's Greer, S.C., office. "It's just a few weeks earlier than usual. But it's the kind of pattern we always see."

3. Aiming at the Southeast.  Tomko said the trough will be strong but broad, rather than deep. What does that mean?  Instead of the coldest of the air surging all the way into the Deep South, it will run out of steam to our north -- over Kentucky, West Virginia and Virginia. "Certainly, colder air will reach our area," Tomko said. "But the coldest air will be held to our north."

As advertised, the cold air is coming

The weather pattern change that we started talking about early last week is unfolding Monday across the northern part of the United States.

A very strong storm system that battered western Alaska last Friday helped create a kink in the jet stream, and that is allowing an outbreak of arctic air to blast into much of the United States.

The cold air will reach the Charlotte region Thursday, but the heart of the arctic outbreak appears to be aimed at the central third of the United States. Places like Des Moines, Iowa, are not forecast to climb above freezing for much of the week. In Dallas, where the front is expected to arrive Tuesday, post-frontal high temperatures will only reach the 40s.

The cold air will trigger an outbreak of heavy lake-effect snow squalls in the Great Lakes.

And forecasters said long-range guidance from the computer models points to a second surge of cold air about a week from now. The coldest of that air might be aimed farther eastward, toward the eastern Great Lakes, the Northeast, and the Southeast.

This change in the pattern will last a while -- probably two weeks and maybe a bit more. That will take us into the beginning of Thanksgiving week.

So far, there are no strong indications that storm systems will form in the Southeast while the heart of the cold is around. And that will prevent an early-season snow or ice event, although there is a chance that a low pressure system expected to form in the Gulf of Mexico on Friday could bring snow to the North Carolina mountains Sunday.

We said good-bye to the 80s with the arrival of a strong cold front a few days before Halloween. Now it looks as if the next outbreak of very chilly air will mark an end to the 70s, at least for a while.

Still looking cold for later next week

Computer guidance still indicates an outbreak of unseasonably cold air will push into the Carolinas next week, although it now appears as if the really chilly conditions might not arrive until Wednesday or even Thursday.

But everything basically looks the same as it did 24 hours ago.

A huge storm system is forecast to develop in the Aleutians on Friday, bringing winds of 75 mph and 45-foot waves into the Bering Sea. That system then will contribute to a kink in the jet stream, allowing polar air to dive southward into the continental United States.

This is a big change in our pattern, and computer models tend to have problems locking onto a solution. That means you might see a lot of changes in advanced forecasts over the next few days.

But barring something unexpected, it appears likely that we'll see temperatures later next week that are more like January than November.

There also are some hints of a storm system developing along the polar front later next week, but let's not get excited about that yet.

Alaska super storm could mean cold November for us

The remnants of a strong typhoon are expected to develop into a super storm off southwest Alaska and then could help bring the Carolinas some of its coldest November weather in years, starting next week.

That is the scenario gaining favor among meteorologists and computer models this week,

Some guidance from the trusted Global and European computer models paint a picture of daytime highs in the 30s and morning lows around 20 degrees in the Charlotte area by the middle of next week, in fact.

How will all this happen?

It starts with Typhoon Nuri, which was a Category 5 storm with 180 mph winds before weakening northeast of Japan during the past day. Nuri is forecast to swing northeast, into the north Pacific, and head toward the Bering Sea as it morphs into a very powerful non-tropical system.

In its morning summary, the National Weather Service office in Anchorage said the Aleutians storm could set a record for lowest barometric pressure Friday. Winds in the western Aleutians are forecast to be at hurricane force, with waves of 43 feet or more.

This is where the forecast moves into the "theory" category.

Meteorologists have noticed in recent years that strong storm systems near Alaska can ripple the jet stream, causing a big dip from Alaska across western Canada and into the eastern United States. That is the recipe for blasts of cold air to push into areas east of the Mississippi River.

You can find a write-up of this situation here and there's another one here.

The computer models are picking up on this situation and are predicting a surge of cold air into the United States around Tuesday or Wednesday of next week. Typically, a pattern shift like this doesn't go away quickly, and this could persist through the month of November.

Last weekend's snowfall in the Carolinas, interestingly, was the work of the remnants of another former tropical system, Hurricane Ana, which had threatened Hawaii earlier.

We'll be watching this situation over the next week.