Monday, April 20, 2009

A transitional weather pattern


The Mid-South will be transitioning between weather pattern in the upper levels this week that will definitely be noticed down here on the ground as well! Coming out of a stormy pattern over the weekend, when nearly 2" of rain was recorded at WXLIVE!, the next 36 hours will be dominated by an upper level trough (or low pressure) leading to some clouds and cooler temps. In fact, an impulse in this trough will swing through this evening bringing with it an isolated shower or two, more likely northeast of the metro region. Any passing shower will be brief. Tomorrow will see highs in the 60s area-wide with a gusty northwest wind and partly cloudy skies.

As we head into the middle of the week, the upper level trough will be replaced by building high pressure (the pattern shift). This will manifest itself as warming temperatures (quite warm by the weekend in fact) and fair weather with some afternoon puffy cumulus clouds as moisture and humidity increase later in the week into the weekend. Look for temperatures to be much warmer - 80s for highs beginning Thursday and lasting through the weekend. No major storm systems look to affect our weather through early next week. The movie loop above shows this transition, as the brighter colors (impulses in the upper atmosphere) move out and then stay north of us, and we're left with the ridge of high pressure dominating the south-central and southeast U.S.

Last week's blog poll asked readers when they expect Memphis to reach a high of 85 degrees the first time? Half of the votes came in "between April 26-May 5" and half were after May 5. Given the current regime, I'd say there's a decent chance the earlier votes could be correct!

The forecast will keep you updated on how the pattern shift will affect you this week.

No comments: