Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 400 PM EDT Thu May 26 2016 Valid 00Z Fri May 27 2016 - 00Z Sun May 29 2016 ...Showers and thunderstorms with possible severe weather will continue across much of the Plains and into the Midwest... ...Tropical downpours are forecast to spread into the coastal sections of the southeastern U.S. during the weekend... An upper-level shortwave trough is moving across the southwestern part of the U.S. Instability associated with this cold core upper trough is expected to trigger showers and thunderstorms from the Sierra Nevada eastward across the Great Basin into the central and southern Rockies. Some of the highest elevations are cold enough to see snow to fall. These showers will be most active from the late afternoon into the evening hours, and should gradually taper off overnight. The same shortwave trough will move out into the central Plains on Friday, and will act to invigorate more showers and thunderstorms with possible severe weather from the central and southern Plains Friday afternoon into the evening. As the main energy slides off towards the Great Lakes and weakens on Saturday, the severe weather threat should gradually diminish across the Plains during the weekend. Colder air dipping down from western Canada associated with an upper-level low is expected to bring some higher elevation snow across the northern Rockies on Saturday. Elsewhere, summer-like heat with increasing humidity will prevail along much of the eastern Seaboard. Farther off the southeast coast of the U.S., the National Hurricane Center has been monitoring an area of disturbed weather off the Bahamas for potential tropical cyclone formation. Computer models generally agree that a low pressure center will approach the southeastern U.S. coast on Saturday. It appears that tropical downpours ahead of this system are expected to reach the coastal sections of the southeastern U.S. by Saturday. Kong Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php