Overview
- Multiple official alerts are in effect: Heat Advisories for Columbus, Mississippi and Coastal Georgia, an Extreme Heat Warning for the San Diego deserts through Friday, and Red Flag Warnings for parts of central and eastern Washington.
- Forecasters say the Storm Prediction Center has placed Columbus, Mississippi in a marginal severe risk and Mid‑Atlantic agencies have flagged Thursday for possible strong to severe storms with damaging winds and heavy downpours.
- Monsoon and tropical moisture creeping inland is boosting humidity in Southern California and the Interior West and raising the chance of afternoon and evening mountain and desert storms that may produce heavy rain, strong winds, lightning, small hail and localized flooding.
- Inland and northern areas from Montana to Maine and Metro Detroit face rising shower and thunderstorm chances late this week into the weekend with cooler, drier air expected to follow behind passing fronts for short‑lived relief.
- The heat pattern grew from a multi‑week upper‑level ridge that trapped warm air and moisture, and the recent westward shift in that ridge is now increasing storm and forecast uncertainty while keeping heat, overnight humidity, power strain and localized wildfire risk high.