Overview
- National Weather Service heat advisories and Extreme Heat Warnings remain in force on Saturday across large parts of the central and eastern U.S., with highs in the upper 90s and heat‑index values commonly in the triple digits.
- The Storm Prediction Center and local NWS offices have placed some metro areas under enhanced or marginal severe risk for afternoon and evening thunderstorms that can produce damaging wind gusts, frequent lightning and heavy downpours.
- Coverage will be highly localized so many communities may stay dry, but timing uncertainty means storms could force people to quickly leave parades, parks and fireworks sites where they develop.
- Forecasters expect a frontal passage late Sunday into early next week that should bring noticeably cooler, drier air and drop highs into the 70s–80s by Monday and Tuesday.
- Cities and utilities have opened cooling centers and urged conservation to reduce heat‑related health and grid strain, and officials warn people to stay hydrated, check on vulnerable neighbors and monitor weather alerts for sudden storms.