Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 350 PM EDT Sun May 08 2016 Valid 00Z Mon May 09 2016 - 00Z Wed May 11 2016 ...Strong to severe thunderstorms possible from the Southern and Central Great Plains to the lower and mid Mississippi Valley... ...Heavy rainfall accumulations possible for portions of the Midwest... ...Locally heavy snows possible for portions of the northern Rockies late Monday into Tuesday... A broad upper low currently centered over the Four Corners region is expected to slowly lift northeastward through midweek. A slow-moving cold front will cross the northern/central Rockies into the Great Plains- the northern flank will become quasi-stationary in across eastern Montana and southern Saskatchewan while the southern flank pushes into the Central/Southern Plains trailing in the Great Basin. Scattered showers and thunderstorms will continue for areas east of the Sierras and along the Rockies. Locally heavy snow will be possible across the highest elevations of the Northern Rockies through Wednesday. Cooler than seasonal average temperatures will persist across the northern Rockies and high plains on Monday and Tuesday. Strong to severe thunderstorms may develop across the Southern/Central Plains as moist, unstable air draws into the system from the Gulf of Mexico. The Storm Prediction Center has highlighted much of the Southern and Central and into the Lower and Middle Mississippi Valley with a slight risk for severe storms through Monday morning- with an enhanced threat for Oklahoma and Kansas. The favorable area for an enhanced threat will shift further east for Monday afternoon through Tuesday morning, encompassing the portions of Northeast Texas, extreme northwest Louisiana, Arkansas, eastern Oklahoma, southeast Kansas and southwest Missouri. The greatest potential for heavy rainfall accumulations is expected to center across the Lower Missouri and Middle Mississippi Valleys. Moisture advecting from the south is forecast to focus along a slow moving frontal boundary, supporting heavy rains across the region. An excessive rainfall outlook has been issued for this region. Scattered showers and thunderstorms are forecast to initiate today in the Northeast and Mid-Atlantic region as a frontal boundary drops southward. Meanwhile, high pressure and dry conditions are likely to prevail across the Southeast. Campbell Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php