Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 338 PM EDT Tue Apr 18 2017 Valid 00Z Wed Apr 19 2017 - 00Z Fri Apr 21 2017 ...Heavy rainfall will be possible along a frontal boundary as it progresses from the Central U.S. into the Northeast Wednesday and Thursday... ...Strong to severe thunderstorms are possible on Wednesday for portions of the central Plains and middle to upper Mississippi Valley... ...Rain and mountain snow returns Wednesday and Thursday for the Northwest... Rain and thunderstorms will spread eastward from the Intermountain West and the Rockies into the northern Plains this evening along a frontal boundary pushing through the region. By Wednesday and Thursday, heavy to excessive rainfall will continue to develop along the boundary as it drops through the Central Plains and progresses eastward into the Ohio Valley and the Northeast. Strong to severe thunderstorms are also possible along the boundary on Wednesday and the Storm Prediction Center is highlighting a slight risk area from central Kansas to southern Iowa and far northwest Illinois. Wintry weather may also possible on Thursday across portions of the Upper Great Lakes, as well as far northern Maine. Elsewhere, conditions should dry out briefly tonight across the Northwest U.S. but rain and higher elevation snow will return Wednesday as an upper level system pushes towards the coast. As the system moves inland on Thursday, expect precipitation to move eastward into the Intermountain West and the Rockies. Showers and thunderstorms may also be possible across the Southeast and southern Mid-Atlantic states on Wednesday near a frontal boundary lingering across the region. Santorelli Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php