Overview
- This weekend many regions reported triple‑digit highs, designated Impact Days, Heat Advisories and some Extreme Heat Warnings that pushed heat‑index values above 100 degrees and kept overnight lows unusually high.
- Monsoonal moisture returning to the interior West has raised afternoon shower and isolated thunderstorm chances in the Sierra and Southwest with lightning that can start fires in dry fuels.
- The Storm Prediction Center has outlooked pockets of the Midwest and Great Lakes in Marginal to Slight risk for isolated strong storms early next week that could produce damaging winds, hail and heavy rain.
- The National Hurricane Center is monitoring two tropical waves in the Atlantic with short‑range development odds near 20% and 40% but neither poses an immediate threat to U.S. coasts.
- Forecast models show the ridge shifting east next week which should allow onshore flow or frontal passages to lower temperatures and humidity for many areas by mid to late week, easing stress on public health, power systems and wildfire danger.