Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 457 AM EDT Sun Jun 15 2014 Valid 12Z Sun Jun 15 2014 - 12Z Tue Jun 17 2014 ...Possibility of flash flooding for portions of the Mississippi Valley/Upper Midwest... ...Strong to severe storms will impact the southern Plains through the Upper Midwest... ...Unsettled weather expected for the Pacific Northwest and northern Rockies... A deep upper level trough is beginning to dig over the central U.S. and is the driving force for convective weather for the Plains and Upper Midwest. These strong to severe thunderstorms will stay ahead of the frontal boundary as it pushes eastward through the short term. By midday Sunday, the convection will spread into the Mississippi Valley and Upper Midwest. With high amounts of moisture and instability in place, there is the chance of flash flooding, along with severe weather, for portions of the these regions especially in the early half of Sunday. The convection will be progressively moving east from the Upper Midwest across the Great Lakes but will be a bit slower for the Mississippi Valley. Monday morning will still be quite stormy for Missouri and portions of Illinois and Indiana as the cold front begins to stall. By Tuesday morning, the cold front finally pushes east of the Mississippi Valley, but the chance for scattered showers and thunderstorms remain but will not be as organized. The active period continues for the Pacific Northwest as an upper level low deepens as it moves southward along the coastline of British Columbia. Showers and thunderstorms will fire off across the Pacific Northwest and the northern Rockies as this upper low dips down toward the Pacific Northwest. By Monday evening, this upper low is expected to deepen significantly. This will assist in producing moderate showers and thunderstorms along and east of the northern Rockies. As for the northern Plains, a warm front associated with the front driven by this upper level low will lift north over the region on Monday afternoon and into Monday night. This will be bring yet another round of showers and thunderstorms to the region. Fanning Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php