October Chill Targets the East, Summer Returns in the West

Just in time for the first weekend in October, a plunge of chilly air is driving south and providing a crisp taste of fall in the Midwest and East. Meanwhile, the West coast has heated back up.

 Changes, however, are in the wind, and they will continue through the weekend. An upper-atmospheric trough is carving southward into the East and Midwest, while a corresponding upper-atmospheric ridge builds into the West (previously, we had had a ridge in the East and a trough in the West).

This pattern change has brought temperatures that are 20-30 degrees colder for some locations in the northern Plains. Temperatures will also be cooler in parts of the Midwest and Northeast, where highs are going from the 70s and 80s last weekend to the 50s and 60s, with a few locations in the Midwest even staying in the 40s, this weekend.

 Fall is definitely a season of change and this will be apparent to many as we head through early October.

http://www.wunderground.com/news/pattern-change-ahead-20140927