Tuesday, November 16, 2010

Atmosphere primed for trouble today

It won't take much to set off severe weather later Tuesday afternoon and early evening across the Charlotte region.

A low pressure system is moving northeast, on a track just west of the Appalachians. As the system moved into eastern Tennessee and Kentucky, it dragged a warm front northward across North Carolina. That put the Charlotte area in an area known as the "warm sector."

Being in the "warm sector" can mean trouble.

In today's case, it means strong winds are blowing from different directions at different levels of the atmosphere. That is known to meteorologists as shear. High levels of shear often are associated with severe thunderstorms and tornadoes.

"Shear is through the roof today," National Weather Service meteorologist Neil Dixon said early Tuesday afternoon.

But it takes another factor -- instability -- to combine with high levels of shear and create severe weather.

In the summer, daytime heating often causes air currents to rise in the atmosphere. There's your instability.

But there's not much daytime heating at this time of year, so the instability has to come from another source.

That source might be a cold front crossing the Southeast today. That front is expected to move across the Charlotte area early this evening and might produce small lines of showers and thunderstorms. If storms develop, they could become tornadic.

Severe storms and tornadoes at this time of year are especially dangerous because they can arrive with little warning.

"In this type of situation, it's possible to get a tornado without any lightning," Dixon said.

By later this evening, the cold front should have passed east of the Charlotte area. That will put an end to the severe weather threat.

My guess is the most likely place for severe weather will be in eastern North Carolina, where the instability levels probably will be higher than in the Charlotte area. But this is a situation worth watching today.


Anonymous said...

Will you stop predicting rain for Charlotte. That is what keeps it from raining here. If you keep up the rain predictions, we will have another extreme drought.

Anonymous said...

Why do the people predicting the weather pray upon people's fears?

Anonymous said...

No disrespect Steve....but are you a meteorologist or just a weather fan? Not sure how growing up in Ohio qualifies one to be a weather "expert". I grew up in Texas....does that mean I get an article in the Observer to talk about the heat?

Anonymous said...

It's simple Mr. Anonmyous-I Grew Up In Texas, if you don't like the blog, go somewhere else.

Anonymous said...

I don't think asking the credentials of someone who has a public forum under the guise of "The Weather Guy" is unreasonable.

I do question someone whose only qualification stated on his bio is that he grew up in Ohio.

Besides, Texas weather has much more in common with the Carolinas than Ohio.

Looks like I may be just as qualified.

NoWhinersNeedApply said...

As usual, those who comment on Observer stories can't be bothered to actually read to get their answers, they just whine.

Anonymous, the first blog explained that he is not a meteorologist but a weather reporter who has spent 10-15 years (per that blog entry) researching and reporting on the weather. This is a blog from one "weather geek" for other "weather geeks". It's a discussion. If you don't like it and want a dry meteorologist's prediction, there are plenty out there. Some of us like the more personal tone of this blog and if you think you're more qualified then start a blog of your own.

Anonymous said...

Apparently there is some sensitivity here. I'm sorry that you consider asking a simple question on one's background as whining.

I have nothing against Steve or this blog, just asked for clarification.

I'll leave the blog to the "weather geeks"