Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 400 PM EDT Wed Aug 03 2016 Valid 00Z Thu Aug 04 2016 - 00Z Sat Aug 06 2016 ...Cooler air will move across much of the northern U.S. while summer heat continues for the rest of the country... ...Heavy rain and flash flooding possible for the southern Rockies... A vigorous upper-level disturbance moving eastward across the northern Rockies has triggered the formation of a low pressure system in the northern Plains. As temperatures soar into the 90's this afternoon across the northern Plains, showers and thunderstorms are expected to form ahead of a strong cold front. Some of these thunderstorms could become severe. The cold front will move steadily eastward across the Midwest on Thursday and into the Great Lakes on Friday with showers and thunderstorms extending farther southwestward into across the central Plains. Behind the cold front, pleasantly cool temperatures from the Pacific Northwest is expected to spread into the northern U.S. through the end of the week. Meanwhile, heat and humidity will be unabated across much of the central and southern U.S. Heat advisories are in effect from eastern Texas to Mississippi where heat indices will soar into the 100 to 110 degree range. By contrast, below normal temperatures are expected along the East Coast down into the Southeast as a ridge of high pressure brings cooler air from New England. Much of the Southeast will continue to see showers and thunderstorms near a stalled front. The area of the country with the greatest potential for heavy rain and flash flooding will be from the Desert Southwest into the southern Rockies, especially in the higher terrain of Arizona, northern New Mexico, and southwestern Colorado. An enhanced monsoonal flow from the south will result in the development of numerous showers and thunderstorms each afternoon and evening. Some locations may receive in excess of 3 inches of rain over the next couple of days in southwestern Colorado. Kong Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php