645 FXUS01 KWBC 290632 PMDSPD Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 231 AM EDT Wed Jul 29 2026 Valid 12Z Wed Jul 29 2026 - 12Z Fri Jul 31 2026 ...Severe thunderstorm and flash flooding risk across the Southeast and northern/central Plains into upper Midwest; Flash flooding concerns across portions Northeast through Thursday... ...Monsoonal moisture continues to foster numerous thunderstorms and the risk of flash flooding over the Four Corners, Rockies, and High Plains the next several days... ...Dangerous heat wave expands from the southern U.S. into the Southwest and Intermountain West this week... An amplified upper trough centered over the Great Lakes and Northeast will gradually lift northeastward, while maintaining cyclonic flow across much of eastern U.S. At the surface, a cold front extending from New England southwestward into portions of the Mid-Atlantic will continue to move northeastward through Wednesday. Frontal convergence and anomalous moisture will support another round of repeated rainfall across portions of New England. Potential training may lead to high rainfall totals and rain rates, which can produce flash flooding, especially over urban corridors and areas where soil remains saturated. Therefore, a Moderate Risk (level 3/4) of excessive rainfall has been issued for portion of the Northeast for Wednesday. By Thursday, much of the northern portion of the front will move offshore, but lingering showers may persist across portions of New England, which will continue a risk for isolated flash flooding. Farther south, the tail end of the frontal boundary over the Northeast will drape across the southern/central Plains into the Southeast/Gulf Coast states. This will bring scattered showers and thunderstorms through Thursday as boundary stalls. With the combination of slow moving storms, warm moisture, and instability, heavy downpours will be possible within the organized cells. Therefore, there is a Marginal Risk (level 1/4) of excessive rainfall with a chance for isolated flash flooding for parts of the Gulf Coast and Southeast through Thursday, as repeated rainfall and high rainfall rates are expected. Additionally, Storm Prediction Center (SPC) has highlighted a Slight Risk (level 2/5) for severe thunderstorms across portions of the Southeast for Wednesday. These storms may also be capable of producing severe wind gust over areas with the strongest instability. Across the Southwest, the active monsoonal pattern will continue to bring afternoon and evening thunderstorms across the Four Corners, Rockies, and High Plains through Thursday. Slow storm motions and warm moisture will continue to support localized flash flooding, especially over burn scars, slot canyons, and vulnerable terrain. Therefore, a Marginal Risk (level 1/4) of excessive rainfall continues to remain in place for portions of the Four Corners into the central/northern Plains, while a Slight Risk (level 2/4) is in place over portions of Colorado for Wednesday. Conditions will improve on Thursday as the upper ridge expands, but sufficient monsoon moisture will bring another day of flash flooding risk over the Four Corners. Across the northern tier, a frontal boundary will transverse into the northern Rockies/Plains on Wednesday, while a surface trough will extend across the Plains, bringing chances for showers and thunderstorms along the boundary. With strengthening instability, moist air, and increasing shear, organized convection capable of producing severe thunderstorms and flash flooding may develop. There is a Slight Risk (level 2/5) for severe thunderstorms for portions of the northern High Plains for Wednesday. On Thursday, the frontal boundary will slowly move east-southeastward toward the Upper Midwest, while the frontal boundary over the southern Plains lifts further north. The boundary will interact with increasing moisture and unstable airmass, increasing the risk for flash flooding to a Slight Risk (level 2/4) of excessive rainfall across parts of the northern/central Plains into the Mid/Upper Mississippi Valley. SPC also has a broad Marginal Risk (level 1/5) of severe thunderstorms, damaging winds, and hail for Northern High Plains into Upper Mississippi Valley and Central Plains, with a Slight Risk (level 1/5) over parts of Dakota into Nebraska. Dangerous heat continues across the southern U.S. as the upper ridging remains in place, bringing above normal temperatures through the remainder of the week. Afternoon highs are expected to reach mid to upper 90s, with localized areas seeing up to low 100s across Texas and Oklahoma. Heat indices will reach 105 to 115 degrees with the combination of high temperatures and high humidity, leading to widespread Major to Extreme HeatRisk levels, which will be hazardous to those without adequate cooling or hydration. The heat will begin to expand into the Southwest and portions of the Intermountain West by Thursday. Oudit Graphics available at https://www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php $$