Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 454 AM EDT Thu Jun 19 2014 Valid 12Z Thu Jun 19 2014 - 12Z Sat Jun 21 2014 ...Active weather continues across the central Plains and Mississippi Valley... ...Stormy weather will be expected for the Ohio Valley and Mid-Atlantic... The anomalously strong upper level low is slowly moving across the High Plains and into central Canada. By Thursday afternoon, much of the precipitation across the northern Rockies will continue to taper off as the upper low moves into Canada while the surface front pushes slowly into the Mississippi Valley/Upper Midwest. This will bring both threats of strong to severe thunderstorms and possibility of flash flooding to these two regions. Meanwhile, a slow moving warm front remains draped across the Mississippi Valley to the Mid-Atlantic. Waves along this stationary front will provide focal points for clusters of convection. These waves will progress eastward along the warm front and by Friday and into Saturday, most of the convective activity will be in the Ohio Valley/Mid-Atlantic. However, scattered showers and thunderstorms will still linger across the Mississippi Valley and Upper Midwest. Another upper level low will swing toward the Pacific Northwest/British Columbia coast by Thursday. At the surface, a frontal boundary will begin to move onshore by Thursday evening and an increased coverage of showers will occur through Friday morning. Once the frontal boundary moves across the Rockies and Intermountain West, scattered showers will remain and any of the heavier precipitation will remain along the coastline of British Columbia. This front does not have the impressive upper level support as the previous system did. Consequently, the precipitation will have much less coverage along the Rockies and High Plains. Diurnally driven thunderstorms along the sea breeze will continue across Florida. Most of the activity will be confined to the south and central regions of the state. West Texas will also scattered thunderstorms firing off throughout the short term period. Fanning Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php