503 FXUS01 KWBC 260618 PMDSPD Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 217 AM EDT Sun Jul 26 2026 Valid 12Z Sun Jul 26 2026 - 12Z Tue Jul 28 2026 ...Hazardous heat continues over parts of central and southern U.S. into next week... ...Risk for severe thunderstorms and flash flooding across the Upper Midwest/Great Lakes, Ohio Valley, and portions of the Northeast... ...Risk of severe thunderstorms and flash flooding across Southeast near a stalled frontal boundary... ...Active monsoonal moisture fuels thunderstorms over the Southwest and into portions of the central Plains... A persistent upper-level ridge centered across central and southern U.S. will continue to bring hazardous heat over the next few days. Afternoon highs are expected to reach upper 90s to lower 100s for central and southern U.S., while isolated areas in the Desert Southwest may see up to 115-120 degrees. With hot temperatures and high humidity, heat indices may exceed 105-115 degrees. This will result in widespread Major HeatRisk with isolated Extreme HeatRisk across the Plains, Mississippi Valley/Midwest, parts of the Rockies, and portions of southern U.S. through Monday. With the repeated days of dangerous to extreme heat and warm overnight lows, anyone without adequate cooling or hydration may experience health related health concerns. Across eastern U.S. a progressive northern-stream trough traverses southern Canada into the Great Lakes and Northeast. Embedded shortwave impulses rounding the northern periphery of the ridge will interact with frontal boundaries that will promote organized convection along the front. The quasi-stationary front extending from the Northern Plains into the Upper Midwest will slowly progress southeastward into the Mid-Mississippi Valley, Ohio Valley, and Northeast through Sunday. The combination of strong mid-level flow, instability, and low-level moisture pooling along the boundary will help support severe thunderstorm development and excessive rainfall/flash flooding risk across parts of the Upper Midwest/Great Lakes into Ohio Valley. These storms may also produce large hail and damaging winds across the the Mid-Missouri Valley into the Upper Mississippi Valley and Great Lakes. On Monday, as the frontal boundary slowly pushes further east into the Northeast, the surface low will strengthen, reinforcing the severe thunderstorm and flash flooding threat across the Great Lakes, Ohio Valley, and portions of the Northeast. Over into the Southwest, the deep monsoonal moisture along the southern flank of the ridge will continue to bring unsettled weather. Daytime heating, instability, and sufficient moisture will promote isolated to scattered thunderstorms through Monday. Heavy rainfall rates may lead to localized flash flooding across the Four Corners and central Plains, especially over burn scars and slot canyons where rapid runoff and flash flooding may occur. WPC continues to highlight a Marginal Risk (level 1/4) of excessive rainfall across the Four Corners region through Monday. Across portions of the Southeast, the stationary front and surface trough will support rounds of showers and thunderstorms. With southerly flow maintaining a warm moist environment along the boundary, slow storm motions, and instability, severe thunderstorms and isolated flash flooding may be possible on Sunday. A Slight Risk (level 2/4) of excessive rainfall and flash flooding have been placed for the eastern portions of the Southeast for Sunday. Oudit Graphics available at https://www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php $$