Pattern Update for Sept 20-27 2009

I have come to the conclusion that instead of covering the weather pattern for two weeks at a time that I would cover the weather pattern 1 week at a time much like I am doing for the southeast. 

The next 24-48 hours are going to be controlled by an area of high pressure off the east coast which will be responsible for building a ridge over the area. This high pressure & subsequent ridging will be responsible for a southerly flow and a temporary moderation in temperatures where we could be looking at potentially above seasonal levels. However..do not get use to it. A cold front will approach the area from the west on thursday into friday. 

Meanwhile over the southeast they too will be under the influence of the upper level ridge as the closed ULL over the west retrogrades into the rockies from the plains. 

By about 96 hours out or friday, with the cold front advancing, a trough over southeast Canada will amplify into the northeast and this will send temperatures once again back to seasonal to slightly below seasonal levels.

By about 120 hours out the closed ULL over the west is going to start to make inroads into the east.  

By about 144 hours out this trough will essentially be over the Great Lakes and the east coast. 

As far as precipitation is concerned. Generally any rainfall over the next couple days in association with the cold front approaching will be generally light between a T and approximately .50 on the eastern side of the region to approximately an inch on the western side of the region. Ohio though can see more rainfall with over an inch possible.

There after with the trough moving into place...an area of low pressure could develop over the southeast and move up the east coast bringing a soaking rain to parts of the region. As the time comes closer to this will consider issuing a map for the rainfall that may fall across the area.

Temperatures across the region as stated will be seasonal to slightly above seasonal over the next couple days as the ridge is in control. With the passage of the cold front thursday into friday temperatures will drop back down to seasonal to slightly below seasonal depending on where you reside. With the trough moving into place over the weekend from about sunday on temperatures are expected to be below normal across vast majority of the region!