Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 335 PM EDT Mon Jul 21 2014 Valid 00Z Tue Jul 22 2014 - 00Z Thu Jul 24 2014 ...July heat has returned to the Rockies and Central Plains although temperatures are again expected to cool later this week... ...Another cool Canadian high pressure system is expected to move across the Dakotas on Tuesday and cover much of the Midwest by Thursday. A strong surge of cool air will also move across the Pacific Northwest by Wednesday and Thursday... ...Some severe weather is expected tonight across the Dakotas into Minnesota while scattered thunderstorms will be common across the Gulf Coast into the Southeast and out ahead of the cold front advancing over the Midwest... Hot temperatures are occurring across the Rockies into the Plains states with temperatures in the 90s and approaching 100 degrees. However...another significant cold front is expected to drop southward across the Northern Plains on Tuesday...with a large relatively cool high pressure system covering the Northern Plains and Midwest by Wednesday. The front and cooler temperatures should move into the Northeast on Thursday. Scattered showers and storms will preceded this front from the Midwest to the East Coast. This evening...heavy and possibly severe thunderstorms are expected to develop across North Dakota...northern Minnesota and head into northern Wisconsin and Upper Michigan on Tuesday. Hail and even the possibility of a few tornadoes may occur with this series of storms. While the return of cooler weather across the eastern portion of the nation indicates that the mean upper trough that had dominated the weather over the Eastern US for much of the year...will be coming back by the middle and end of the week...continuing to spare much of the Eastern US the blistering heat that can be common in other years. However...as the trough builds in the East...an upper ridge will build in the West at the same time...allowing heat to persist and return across the portions of the Western into Central United States later in the week. Meanwhile...another powerful cold front is expected to cross the Pacific Northwest on Wednesday into Thursday...bringing showery...breezy and cool conditions from Washington and Oregon into Idaho. Kocin Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php