Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 400 AM EDT Wed Mar 18 2020 Valid 12Z Wed Mar 18 2020 - 12Z Fri Mar 20 2020 ...Snow expected for higher elevations of the Four Corners, spreading into the Plains and Upper Midwest... ...Severe weather and flash flooding for the Southern Plains and Mississippi Valley through Thursday... ...Much below average temperatures in the West and much above average temperatures in the East... An anomalously strong upper-level low is forecast to sit over California through midweek, while upper-level disturbances moves eastward over the Four Corners into the Plains by Thursday. This will generate precipitation across the Intermountain West through Thursday, and with snow levels dropping, snow totals of generally 6 to 12 inches are forecast across the Mogollon Rim, Wasatch, and Central Rockies, with locally higher amounts in the highest elevations. Snow is expected to spread into the Central Plains by Thursday, with a swath of 4 to 6 inches of snow. Blizzard Warnings have been issued for western Nebraska and southeastern Wyoming on Thursday because of a developing low pressure system to the south and strong Canadian high pressure to the north generating strong northeasterly winds. This should lead to drifting snow and whiteout conditions in these areas. Light snow is forecast for the Northern Plains and Upper Midwest as well. Farther east, rain and thunderstorms are expected as a warm front lifts north through the Plains, Mississippi Valley, and Ohio Valley today. There is an Enhanced Risk of severe thunderstorms in place as well as a Slight Risk of excessive rainfall/flash flooding for the Southern Plains today, where the best combination of moisture, lift, and instability will be. Then on Thursday into Friday, a cold front pushes eastward across the Central U.S., and rain and thunderstorms should focus ahead of it. Thus the severe weather and flash flooding threats will shift eastward into the Mississippi Valley and Ohio Valley. Temperatures are expected to be colder than average over California and the Southwest due to the upper-level low, while the Northern Plains will see high temperatures below normal by more than 20 degrees on Thursday as a cold high pressure system builds in. Meanwhile, temperatures in the eastern U.S. are forecast to be more like May temperatures. Today high temperatures should reach into the 70s as far north as the Central Plains and Tennessee Valley, spreading into the Ohio Valley and Mid-Atlantic on Thursday. Tate Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php