Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 344 AM EDT Thu Sep 19 2019 Valid 12Z Thu Sep 19 2019 - 12Z Sat Sep 21 2019 ...Tropical Depression Imelda producing extreme rainfall for parts of Texas... ...Above average temperatures over the Plains and Midwest and cool for the West... The overall weather pattern across the continental U.S. will be rather amplified aloft through the end of the week with an upper level ridge encompassing the eastern half of the nation, a closed low off the East Coast, and a big upper level trough over the western U.S., along with a strong cold front crossing the Intermountain West. The upper level ridge is expected to result in temperatures on the order of 10 to 20 degrees above average from the western High Plains to the Great Lakes region. The western U.S. trough should keep below average temperatures in place from the West Coast to the Rockies, with snow likely for portions of the northern Rockies as the upper level trough axis moves across that region. For the Mid-Atlantic and Northeast, a high quality airmass is anchored in over the region as a strong surface high from Canada governs the overall weather pattern, making it feel more like autumn compared to last week with lower dewpoints and cooler temperatures. Tropical Depression Imelda continues to make weather headlines across eastern Texas. Extremely persistent thunderstorms on the southern flank of the system are producing prolific rainfall and dangerous flash flooding across portions of southeast Texas Thursday morning. A High Risk for excessive rainfall and flash flooding is in effect for parts of these areas on Thursday, with the potential for an additional 6 to 12 inches of rain with isolated higher amounts possible. Storm total rainfall could be in excess of two feet for some areas before the weather finally begins to improve! D. Hamrick Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php