Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 359 AM EDT Tue Mar 17 2020 Valid 12Z Tue Mar 17 2020 - 12Z Thu Mar 19 2020 ...Snow spreads from the Intermountain West across the north-central U.S. over the next couple of days... ...Severe weather and flash flooding forecast for the Southern Plains through Wednesday... An anomalously strong upper-level low is forecast to sit over California through midweek, while upper-level energy moves eastward over the Four Corners by Wednesday night. This will cause precipitation over the Intermountain West over the next couple of days. Higher elevations of northern California and northwestern Nevada could see an additional foot of snow through tonight. Snow levels should lower across the Southwest after cold frontal passages, bringing snow to the Mogollon Rim as well as to the Wasatch and Central Rockies through Wednesday night. Light to moderate snow (totals under 6 inches for the most part) is expected for the north-central U.S. tonight into Wednesday, with some snow spreading into parts of the Northeast Wednesday night. This is before the potential for a swath of heavier snow for portions of the Northern/Central Plains on Thursday. Ahead of the upper-level energy, moisture is expected to flow in from the Gulf of Mexico and interact with a front that is forecast to meander across the Southern Plains to Southeast again today and finally lift northward Wednesday. Scattered showers and thunderstorms are possible all around these areas, but the area with the greatest threats from the storms will be the Southern Plains. Slight to Enhanced Risks of severe thunderstorms are in place along with Slight Risks for excessive rainfall/flash flooding for much of the Southern Plains today and Wednesday. By Wednesday, rainfall amounts over an inch in the Ohio Valley could lead to flash flooding as well. Additionally, the upper low will help cause temperatures that are below normal by 10 to 20 degrees across California into the Central Great Basin and Southwest. Meanwhile, the Gulf Coast states can expect above normal temperatures south of the warm front. The Central Plains should see a large temperature swing over the next couple of days, with highs today in the 40s and 50s but exceeding 70 degrees tomorrow. Warmth on Wednesday will spread into the Ohio and Tennessee Valleys as well. Tate Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php