A swath of dangerous heat and severe-weather threats is expected to stretch from the Midwest to the Mid-Atlantic on Tuesday, July 8, according to the National Weather Service. Forecasters say the combination of oppressive humidity and an advancing cold front will fuel repeated rounds of thunderstorms, some of which could turn severe and trigger flash flooding. In the Washington, D.C. region, a heat advisory will be in effect from 1 p.m. to 7 p.m. as heat-index readings peak near 105 to 107 °F. A flood watch follows from 2 p.m. until midnight, with the Storm Prediction Center assigning the area a level-2-of-5 risk for severe storms capable of producing wind gusts above 60 mph and torrents of rain. Farther north, Philadelphia faces a similar one-two punch. A heat advisory runs from 10 a.m. to 8 p.m., with feels-like temperatures projected between 101 and 104 °F. Forecasters expect evening storms to deliver heavy downpours, damaging wind and localized flooding before weakening overnight. In the Midwest, a line of storms is forecast to sweep across northern Illinois on Monday evening, reaching the I-39 corridor by about 6:30 p.m. Gusts could top 40 mph, and rainfall rates may be intense before quieter, slightly cooler weather moves in for Tuesday. The Twin Cities area is also bracing for scattered storms late Monday and again Tuesday; the strongest cells could unleash damaging wind and hail, with a broader swath of rain likely Thursday into Friday. Meteorologists warn that daily thunderstorm chances are likely to persist through at least the end of the week from the Carolinas into portions of the Plains. Widespread rainfall of 1–3 inches is possible, with higher local totals where slow-moving storms stall. Residents across the affected regions are urged to limit outdoor exposure during peak heat, secure loose objects ahead of high winds and remain alert for rapidly changing weather conditions.