Overview
- A broad area of high pressure is keeping the Northeast, Mid‑Atlantic and parts of the Midwest cool and dry through the weekend with daytime highs mostly in the 70s to low 80s and crisp nights in the 50s.
- Forecast guidance shows humidity and heat building back early next week, with the Storm Prediction Center already flagging Monday for a possible severe‑weather threat across the Great Lakes and Chicagoland area.
- A strong ridge over the Intermountain West is driving a separate, prolonged heat wave in south‑central and southeast Montana with upper‑90s to low‑100s temperatures and Fire Weather Watches in effect.
- South Florida will shift toward a wetter, tropical‑moisture pattern this weekend with frequent afternoon and evening storms capable of torrential downpours, gusty winds, frequent lightning and localized street flooding.
- Near‑term local hazards include a High Surf Advisory for parts of coastal Maine, lingering smoke that may affect air quality, and broader risks from returning heat such as stressed cooling systems, higher heat‑illness chances and elevated fire starts in dry western zones.