Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 355 PM EDT Thu Jun 23 2016 Valid 00Z Fri Jun 24 2016 - 00Z Sun Jun 26 2016 ...Severe weather and flash flooding will be a threat from the Ohio Valley to the Carolinas... ...Showers to move onshore over the Pacific Northwest through Friday... ...Active weather pattern expected across the Plains and Mississippi Valley... Heavy rain with embedded thunderstorms will continue to move across the Ohio Valley eastward into the Mid-Atlantic and the Carolinas tonight and into Friday morning. A front draped across these regions will act as the trigger for these thunderstorms--along with plenty of moisture on tap. Both severe weather and flash flooding will be threats through Thursday night, mostly across the Ohio/Tennessee Valley and southern Mid-Atlantic. As the front pushes farther south on Friday, the heaviest rainfall will concentrate along the Carolina coastline. The threat of severe weather also shifts south and east across Carolinas and the southern Appalachians. The intensity of these thunderstorms will wane by Friday night and into Saturday; however, with the front still lingering, light to moderate showers are still possible on Saturday. Light to moderate showers will move onshore across the Pacific Northwest through Friday as a closed upper level low moves over the region. This upper level low will move into the Intermountain West by Friday afternoon. Most of the rainfall across the Pacific Northwest will taper off by late Friday night as a result. Meanwhile, convection is expected to break out across the central Plains throughout Thursday evening and into Friday. A frontal boundary currently stretched across the Intermountain West and lifting north across the Plains and Mississippi Valley will fire off convection beginning today. The bulk of thunderstorms will move across the central Plains and into the middle/lower Mississippi Valley on Thursday night and into Friday. As the upper level low causing the showers across the Pacific Northwest traverses over the Intermountain West, it will drive the front east and north--with showers and thunderstorms breaking out across the northern and central Plains and into the Upper Midwest. Severe weather is possible along and ahead of the front on Friday across the northern Plains, and the threat shifts to the Upper Midwest by Saturday. Check the Storm Prediction Center for more information on the specific severe weather impacts. Fanning Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php