Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 500 AM EDT Thu Jul 31 2014 Valid 12Z Thu Jul 31 2014 - 12Z Sat Aug 02 2014 ...Heavy rain and thunderstorms will move eastward into the Lower Mississippi Valley on Thursday... ...Conditions will become increasingly wet over the Southeast and Mid-Atlantic states... ...Heavy rains and flash flooding possible over the Southern Rockies... An organized area of heavy rains and thunderstorms will continue to develop to the northeast of a surface low slowly sinking through East Texas on Thursday. Locations surrounding the Ark-La-Tex region should see the highest rainfall totals and greatest chance for any flash flooding. The organized area of rain and thunderstorms will slide farther southeast through the Lower Mississippi Valley on Friday...but the threat for heavy downpours and flash flooding should diminish as the wave weakens while dropping towards the Louisiana coast. A frontal boundary initially shoved well off the Atlantic coast will gradually edge back westward the next few days. The increase in moisture with the approaching front...combined with weak energy aloft...should fuel and trigger showers and thunderstorms across the Southeast on Thursday. Moist upslope flow into the terrain should lead to especially heavy amounts along the Southern Appalachians. Rain and thunderstorms should spread north on Friday...impacting much of the Mid-Atlantic states. Anomalous moisture in place should continue to fuel widespread shower and thunderstorm activity across much of the terrain of the Western U.S. Thursday and Friday. The greatest chance for organized and heavy precipitation will be along the Southern Rockies...and locations across New Mexico and into south central Colorado could see localized areas of flash flooding. Summer heat will continue across portions of the northern Rockies and Intermountain west late this week. Daytime temperatures could approach or reach triple digits beneath a persistent upper ridge amplified over the region. Weak energy rotating around an upper vortex spinning over eastern Canada should trigger scattered showers and thunderstorms across the Great Lakes and Northeast. Gerhardt Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php