Overview
- Extreme Heat Warnings and advisories remain in effect through Friday for pockets of Northeast Florida, Southeast Georgia and the Las Vegas area with heat‑index values often above 105°F and overnight lows in the upper 70s that limit cooling.
- A frontal passage around Wednesday will push drier air into many northern and inland regions, lowering humidity and bringing a few days of more comfortable temperatures.
- Scattered, hit‑or‑miss afternoon and evening showers and storms are expected today and tonight across much of the country, with a marginal severe‑storm risk for parts of the Midwest including the Chicago area where the Storm Prediction Center notes threats of heavy downpours and damaging gusts.
- Forecast guidance converges on a stronger cold front that will slow or stall Thursday into Saturday and produce multiple rounds of showers and thunderstorms with locally heavy totals of 1–3+ inches and an elevated risk of localized flash flooding.
- The pattern—an upper‑level heat ridge feeding hot nights and Gulf/monsoonal moisture—means stressed health and power systems in heat pockets, so officials urge hydration, reduced outdoor exertion, and close attention to local watches and flood alerts while the tropics remain under routine monitoring.