Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 410 AM EDT Thu Apr 13 2017 Valid 12Z Thu Apr 13 2017 - 12Z Sat Apr 15 2017 ...Conditions will be cool and wet over the northwestern U.S. Thursday into Friday... ...Heavy rain and thunderstorms will be possible from the Southern Plains to the Upper Midwest and Upper Great Lakes... ...Above normal temperatures are expected for locations from the Great Plains to the Eastern Seaboard... Conditions will be cool and wet over the northwestern quarter of the Nation Thursday into Friday as a deep upper level trough edges inland over the western U.S.. Broad cyclonic flow will foster widespread shower activity across the region...especially over the favored terrain...and lowering temperatures behind the leading cold front should allow for snow across the higher elevations. Precipitation will come to end Friday into Saturday while surface high pressure off the California coast spreads northeastward into the Pacific Northwest and northern Rockies. East of the trough entering the Western U.S....the combination of moist southerly flow out of the Gulf of Mexico and shortwave energy aloft should help fuel and trigger heavy rain and thunderstorms across the southern to central Plains on Thursday. The best chance for showers and thunderstorms containing heavy rain should shift into the Upper Midwest and Upper Great Lakes on Friday as the shortwave energy lifts northeastward and a warm front surges through the region. Also east of the trough entering the Western U.S....broad upper ridging will keep temperatures above normal from Great Plains to the Eastern Seaboard late this week. Downsloping "Chinook" winds will especially enhance warming east of the northern Rockies on Thursday...where daytime temperatures could approach record highs...but then cooler conditions will fill in behind a cold front clearing the region Thursday night. Gerhardt Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php