Overview
- Widespread dangerous heat continues across much of the central and eastern U.S. with heat‑index values commonly at or above 100°F and official Extreme Heat Warnings or Heat Advisories in effect in some counties.
- Meteorologists expect scattered afternoon and evening thunderstorms Friday and Saturday that will be very localized and model‑sensitive so some communities may stay dry while nearby areas see lightning, torrential downpours, gusty winds and brief flooding.
- Forecasters warn that storm timing is uncertain and may disrupt daytime parades or evening fireworks, so people with outdoor plans are being urged to monitor local radar, apps and National Weather Service alerts for last‑minute changes.
- Regional contrasts matter for planning: much of the high desert West will stay dry and warm with a local heat risk, while the humid Midwest, Great Lakes and East Coast face the greatest storm and lightning hazards.
- Relief is expected as a frontal trough moves in Sunday into early next week bringing modest cooling, lower humidity and a reduced risk of triple‑digit heat but a continued chance of showers as the pattern changes.