Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 459 PM EDT Wed Jul 30 2014 Valid 00Z Thu Jul 31 2014 - 00Z Sat Aug 02 2014 ...Heavy rains are expected to move eastward into the Mid-Mississippi Valley during the next couple of days... ...Pleasantly cool weather is expected to continue across the eastern half of the Nation for the next couple of days... An upper-level impulse that moved off the central Rockies has been a triggering mechanism for heavy rains and thunderstorms across Oklahoma today. This area of heavy rain is expected to move steadily to the east-southeast ahead of a surface frontal low pressure system. The rain can be heavy enough to cause areas of flash flooding tonight into tomorrow in the south-central Plains. By Friday morning, as the system reaches the lower Mississippi Valley, the intensity of the rain is expected to diminish somewhat. An anomalous deep trough continues to dominate the weather over the eastern half of the Nation, providing unusually cool temperatures over a large portion of the country east of the Continental Divide for the middle of summer. The Great Lakes will again see low temperatures as cold as the mid-40's in the middle of summer along with scattered showers and thunderstorms, some of which can be lake-enhanced! Typical summer heat and humidity will be confined to the Texas Gulf Coast and southern and eastern Florida. Meanwhile, heat is expected to persist from the Intermountain West eastward into Montana under an upper-level ridge. Farther south...monsoonal moisture will continue to fuel scattered showers and thunderstorms over the Great Basin and into central and southern Rockies. Typical summer heat will continue across the Desert Southwest. Kong Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php