Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 328 AM EDT Wed Jul 08 2015 Valid 12Z Wed Jul 08 2015 - 12Z Fri Jul 10 2015 ...Flash flooding possible from portions of the southern plains to the Ohio Valley... ...Showers and thunderstorms expected for portions of the Intermountain West... ...Above average temperatures for the Pacific Northwest and below average temperatures for the central US... A slow moving frontal system stretched from the lower Great Lakes to the southern Plains will continue to produce a widespread area of showers and thunderstorms from the Mid-Atlantic to the southern Plains the next several days. Heavy rainfall ahead of the boundary should continue today from parts of the southern Plains to the Ohio Valley as a wave of low pressure develops along the boundary and tracks northeastward into the Ohio Valley by Thursday morning. Given the very moist airmass in place and the already wet soils from recent heavy rains, flash flooding is expected to be a threat on Wednesday across these areas. The western edge of this boundary is forecast to lift north as a warm front prompting another round of heavy rainfall across parts of the central Plains, where WPC is highlighting a slight risk for flash flooding on both Wednesday and Thursday. In the wake of this system, temperatures across much of the central U.S. could be 10 to 20 degrees below normal the next few days. A second cold front will move across the northern Plains Wednesday, but is expected to weaken and dissipate by Thursday morning. Showers and thunderstorms in this region this morning should continue into this afternoon. Out west, an upper-level low off the California coast will move inland by this afternoon. This system, combined with monsoonal moisture, will allow for the development of showers and thunderstorms across the intermountain West as well as the central and southern Rockies through the forecast period. For the most part, these showers should be most widespread in the afternoon hours coinciding with peak daytime heating. As has been the story for a while now, high pressure in the mid to upper levels remains parked over the Pacific Northwest allowing for the hot and dry weather to continue with temperatures as much as 10 to 15 degrees above normal. Santorelli Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php