Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 500 PM EDT Tue Jul 29 2014 Valid 00Z Wed Jul 30 2014 - 00Z Fri Aug 01 2014 ...Heavy showers and thunderstorms expected to spread from the central Rockies eastward into Oklahoma and Texas Panhandle... ...Unusually cool weather continues to dominate much of the eastern half of the Nation... During the short-term forecast period, an unusually broad and deep upper-level trough will continue to dominate the weather across much of the eastern half of the Country. Temperatures underneath this upper trough will remain unusually cool for mid-summer. Conditions will be very pleasant across a wide area from the Mississippi Valley eastward through much of the East Coast. Typical summer heat and humidity, along with a chance of showers and thunderstorms, will be confined well to the south along the Gulf Coast and into Florida. Over the Great Lakes, where it is closest to the upper-level low center in southern Canada, instabilities will lead to scattered showers and thunderstorms with very cool temperatures. The below normal temperatures will extend westward into a good portion of the Rockies where monsoonal type showers and thunderstorms will be the rule over the next few days. An upper-level impulse is forecast to move across Colorado tonight. This feature will generate its own pool of cool air and will promote additional showers and thunderstorms to spread eastward into the central Plains, especially Oklahoma and Texas Panhandle. Some of the rains can become heavy and could lead to flash flooding in some areas. The clouds and rains will lead to even cooler temperatures of more than 20 degrees below normal in eastern Colorado on Wednesday. The cool pool of air will then spread south across much of Texas on Thursday. The only area where temperatures are expected to be significantly above normal will be in the Pacific Northwest into the northern Rockies where little or no precipitation is expected. Kong Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php