Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 411 PM EDT Mon Aug 18 2014 Valid 00Z Tue Aug 19 2014 - 00Z Thu Aug 21 2014 ...Slight risk of severe thunderstorms over parts of the Upper Mississippi Valley... ...Heavy rain possible over parts of the Southwest... Severe weather is possible along a cold front as it moves across the Upper Mississippi Valley today. The associated upper level energy will slide toward the Great Lakes with warm advection precipitation expected ahead of the surface low. The cold front will drop southeastward toward the Mid Mississippi and Ohio Valleys with showers and thunderstorms expected ahead of the front. While much of Mid Mississippi Valley and Central Plains will be capped in one way or another, the Ohio Valley could see more organized thunderstorms tomorrow afternoon. Steep low level lapse rates will yield modest energy for strong to severe storms to develop in the afternoon. In the Southwest, the monsoon will be in full swing over the next few days. An upper level low digging off the California coast will draw tropical moisture northward from the Eastern Pacific. Showers and thunderstorms will break out in the afternoon today and tomorrow across much of the Southwest and Intermountain West. A strengthening jet aloft along with the approaching mid level energy will provide plenty of ascent to get convection going even in the low CAPE, low shear environment. While thunderstorms will not be organized, the coverage will be sufficient enough to warrant flash flooding concern with anomalous moisture in place. Krekeler Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php