Warmth to return; could stay for Thanksgiving

Those of you who wish for snow and ice during the winter would love having the current weather pattern in January or February.

We've swung into a Negative NAO (North Atlantic Oscillation), which, for lack of a better description, is like an atmospheric roller-coaster. We in the Carolinas are near the bottom.

Air masses tumble southward out of Canada, curve eastward at the bottom of the roller-coaster, and then swing back to the north again, as if they're headed back up a hill. That pattern tends to bring not only cold air into the Southeast, but it also can produce a nor'easter or winter storm if low pressure gets into the atmospheric steering current.

Such a nor'easter is moving up the East Coast on Wednesday, threatening areas that were hit by Hurricane Sandy with more high water.

Temperatures in the Carolinas have been well below average recently, but the NAO is going positive soon, according to meteorologists -- before possibly going negative again after Thanksgiving.

The NAO was positive much of last winter, and the result was mild weather. Another string of mild days is likely to begin later this weekend or early next week, and it could last to Thanksgiving. Such a pattern likely would produce temperatures during Thanksgiving that are near or above-average -- similar to last year.

We might have reached the bottom of the barrel -- at least, in the current cold snap -- on Wednesday morning. The temperature fell to 29 degrees at Charlotte-Douglas International Airport, and that's the coldest since a 24-degree low March 6. If you're keeping count, that's eight months ago.

There was frost and even a freeze, which brought the growing season to an end for most people in the region.

A couple more cold nights are in store for Charlotte, with lows of 32 to 35 degrees Thursday and Friday mornings.

But then a warming trend will start. We'll see highs climb a few degrees each day, until they're near 70 degrees Sunday and Monday.

The GFS computer weather model is hinting at the development of a storm system around the middle of next week -- a warm-air system that could produce severe weather across the South.

After that, if the NAO really goes positive as it's expected to, we could continue with the mild weather for another 7-10 days, into Thanksgiving.

And then we could go back into the freezer again, if the NAO goes negative.

By the way ... some meteorologists believe we'll see plenty of NAO-negative time in the eastern United States this winter, especially after mid-January.