Sunday, July 13, 2014

Polar vortex this week ... in July?


Monday morning update: Well, common sense has taken over. The latest computer models show high temperatures for the middle and end of the week, after the cold front passage, in the mid 80s. This is certainly cooler than average, but it's also not anything in the "remarkable" category.

It'll be a break from the recent 90s, but it will still feel like summer. After all, this is July and we're in the Carolinas.

Earlier post: There has been a lot of conversation in weather circles about a rather unusual meteorological event that is likely to take place this week in the eastern United States.

Some are calling it the return of last winter's "polar vortex" -- a deep low pressure system over eastern Canada that drags cool air into the eastern part of the United States. Back during the winter, especially in January, when Charlotte averaged nearly 5 degrees below seasonal norms, the polar vortex was blamed for the extremely cold weather that settled into the East.

It was responsible for temperatures that plummeted far below zero in the Great Lakes and Northeast. The Carolinas weren't immune either.  My birthday, Jan. 7, featured a morning low of 6 degrees that ruptured a lot of water pipes.

If you look at the weather map, this week's forecast conditions bear some resemblance to last winter. Once again, a deep low pressure system will move across Canada and take up residence in the eastern part of the country. The Washington Post's weather crew, the Capital Weather Gang, examines the situation in this article.

The National Weather Service office in Greer, S.C., began discussing the situation late last week, when it appeared as if the Eastern Canadian low would drive a strong cold front through the Carolinas and off the coast.  In that situation, Charlotte could experience high temperatures at mid and late week in the upper 70s and lower 80s.

But now the computer models suggest the cold front won't make much progress south of the Charlotte region and eventually will stall just to the south. That seems more logical, given the time of year and our location in the South.

Still, it appears as if we're looking for unusually cool weather this week for the middle of July. And to the north, farther away from the stalled cold front, this week's temperatures will be unusually chilly. Some of the Great Lakes cities like Cleveland, Detroit and Chicago might struggle to get into the low 70s at midweek.

It's not really a "polar vortex," because the source of the system will be Alaska, not the polar regions. But this week apparently will give Charlotte-area residents a definite break from the type of mid-July heat we're accustomed to.

4 comments:

Anonymous said...

This time of the year, you take whatever relief comes your way.

Mark Caplan said...

As of Sunday evening, AccuWeather is predicting temperatures 3 degrees below normal for midweek.

Anonymous said...

How dare you let facts get in the way of media hyperbole?

freezin in the Carolina's said...

Anon: Your reference to 'relief at this time of year' as if a cool down into the 80's is a good thing simply does not compute with me. Especially after the incredibly cold winter and the equally disappointing cool summer of last year in which it seemed like there were less than 7 days/nights that truly qualified as worthy of summer; i.e., Highs 90-100+ and Lows of something north of at least 72 with abundant humidity throughout. The hotter the better and if these Polar Vortex start becoming a trend, then it's time to pack up and move to Key West.