Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 355 PM EDT Fri Sep 22 2017 Valid 00Z Sat Sep 23 2017 - 00Z Mon Sep 25 2017 ...Below average temperatures in the western half of the U.S. with above average temperatures in the eastern half... ...Heavy rain and thunderstorms in the central U.S. along a slow-moving cold front... A deep upper-level trough is in place across the western U.S., while an upper-level ridge is present over the northeastern U.S. At the surface, a cold front is located on the eastern edge of the trough, stretching from the Northern Plains into the Southwest. This setup is leading to a strong temperature contrast across the U.S. The West is expected to be much colder than average over the weekend, with temperatures forecast to be up to 30 degrees below average in Wyoming in particular. On the other hand, the eastern U.S. will have widespread high temperatures in the upper 80s and lower 90s. This is 20-30 degrees above average in the Upper Midwest and the Northeast. The trough will shift gradually eastward over the next couple of days, allowing the cold front to move slowly with it, stalling by Sunday. Along the front, rain and thunderstorms are likely for the Plains and into the Upper Midwest through the weekend. Some storms are forecast to contain heavy rainfall, leading to a slight chance of flash flooding. Today and tonight there is a slight risk of severe weather for portions of the Upper Midwest as well. Behind the front in the cold air, snow is expected to continue for the Northern and Central Rockies and in the Central Great Basin. Post-Tropical Cyclone Jose will continue to weaken off the coast of the Northeast, and light rain and wind gusts occurring in New England will subside as it weakens. High surf along the East Coast and hazardous marine conditions could continue through the weekend, however. See the National Hurricane Center's website for more information on Jose. Elsewhere, warm temperatures and plenty of moisture will help form scattered thunderstorms along the Gulf Coast and in the Southeast through the weekend. Tate Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php