Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 359 PM EDT Wed Sep 19 2018 Valid 00Z Thu Sep 20 2018 - 00Z Sat Sep 22 2018 ...Severe thunderstorms and flash flooding are forecast for the Upper Midwest... ...Moisture from newly formed Tropical Depression Nineteen-E will cause heavy rain in the Southwest and Southern Plains... ...Much above normal temperatures for the Middle Mississippi Valley eastward... An upper-level trough is forecast to move through the northern U.S. through the end of the workweek. At the surface, a front stretched across the Intermountain West, Central Plains, and Middle Mississippi to Ohio Valley will move minimally through Thursday, but finally move more on Friday as a surface low strengthens and moves through the Central Plains, Upper Midwest, and into Ontario, Canada. The upper-level trough to the west and the front will both support rain and storms forming across the Northern Great Basin to the Northern and Central Plains and into the Upper Midwest. The heaviest rain will be across parts of the Northern Plains to Upper Midwest. Through tonight, there is a Moderate Risk of excessive rainfall/flash flooding in those areas, with a Slight Risk for parts of the Upper Midwest tomorrow. Flash Flood Watches are in effect. Additionally, the Storm Prediction Center has outlooked an Enhanced Risk of severe weather for portions of the Upper Midwest tomorrow. Tropical Depression Nineteen-E has formed in the Gulf of California, and expected to move into northwestern Mexico Wednesday evening. The moisture plume from this system will lead to heavy rain across the Southwest, particularly through Wednesday night but into Thursday as well. A Moderate Risk of excessive rainfall is in place through Wednesday night, and Flash Flood Watches are in effect. A cold front developing from the strengthening low across the Plains, plus the very moist air continuing to stream in, will lead to rain and thunderstorms for the Southern Plains by Thursday night. Temperature-wise, the aforementioned front will delineate where above and below average temperatures will occur. The Middle Mississippi to Ohio Valleys and southward will see high temperatures in the 90s on Thursday, around 10 to 15 degrees above normal for this time of year. Warm temperatures are expected to spread into the eastern U.S. on Friday. On the other side of the front, temperatures are forecast to be 10 to 20 degrees colder than normal across the Northern High Plains on Thursday. These colder temperatures will even support some snow falling in the higher elevations of the Rockies. Tate Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php