Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 400 PM EDT Tue Sep 03 2024 Valid 00Z Wed Sep 04 2024 - 00Z Fri Sep 06 2024 ...Heavy rain and flash flood potential to spread east from south-central Texas to the Gulf states the next couple of days... ...Heat wave builds over the Southwest and parts of the West Coast this week... Much of our unsettled weather will focus over portions of south-central Texas and the Gulf Coast states this week as a stationary front and coastal low drive multiple days of widespread showers and thunderstorms across the region. In the short term, scattered flash flooding could continue across south-central Texas into the overnight hours as slow moving thunderstorms persist, with several Flash Flood Warnings noted over the Edwards Plateau. South-central Texas should dry out tomorrow morning as a passing disturbance and associated inverted trough shift the main axis of rainfall eastward toward southeast Texas and the central Gulf Coast. Owing to a steady supply of Gulf of Mexico moisture flowing into the front and surface trough, the current forecast calls for rainfall amounts of 2-5" (locally higher) along and near the central Gulf Coast through Thursday, which could lead to locally impactful flash flooding where higher rainfall totals materialize. Storms will also increase along the southeastern Atlantic Coast by tomorrow, and daily thunderstorm chances will continue for the Florida Peninsula. Further north, an upper-level trough and associated surface cold front will bring showers and thunderstorms to the northern Rockies today. Some locally heavy downpours will be possible with an isolated threat of flash flooding over central Idaho and southwestern Montana. Ahead of this system, an upper-level ridge over the northern/central High Plains will lead to another day of well above average, hot late-Summer temperatures, particularly over the northern High Plains. Forecast highs are into the 90s, with some upper 90s possible for the western Dakotas. The approaching system from the west will help to bring temperatures back down to average tomorrow, with highs in the low to mid-80s. Showers and storms are expected with the passage of the system, particularly over the central High Plains. Storms chances will also spread into the Upper Midwest as the system continues east Wednesday night. Out attention turns to a building heatwave over the West by tomorrow. On Wednesday, temperatures will soar into the low 100s over interior California and into the 90s in the Pacific Northwest. While not as hot, much above average temperatures are expected for coastal areas too, with highs into the low 80s for some locations. Heat-related warnings and advisories have been issued for the Desert Southwest and central/southern California outside of the immediate coast given a heightened risk for heat-related illness, especially for those without access to effective air conditioning. Elsewhere, most of the eastern U.S. outside of the the South will be dry with generally mild temperatures. Early Fall-like highs in the 70s are expected throughout New England, the Mid-Atlantic, and Carolinas through Thursday. Asherman/Putnam Graphics available at https://www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php