Monday, January 18, 2010

Thunder Still Possible

Thunderstorms are still possible for the weekend.

Forecast models have been advertising warmer air moving up the Mississippi River Valley later this week ahead of an area of low pressure moving across the country. As previously mentioned, with the warm, moist air in place interacting with a cold front passing through early Sunday morning there will be a chance of thunderstorms.

Looking at the jet stream in the atmosphere (30,000'-35,000') shows energy coming out of the south-central United States.

Here is a look at the GFS model's depiction of the 300mb level at 6pm CT Saturday.

The nose of the jet streak comes around the upper-level low across the central Plains. The nose of the jet streak is shown moving up in to southern Missouri. If this holds true, strong thunderstorms (perhaps severe) will develop across eastern Arkansas, northern Mississippi, and extreme western Tennessee.

The Storm Prediction Center has taken notice of the possibility of severe weather. They have highlighted areas of Arkansas (and south) for the potential for strong storms.

The question would be how far north could the strong storms develop?

A local study by the National Weather Service shows that "cool season" severe thunderstorms do not need a lot of instability to thrive. They just need marginal moisture amounts (dew points), a decent cold front, and wind aloft.

Stay tuned...

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