Overview
- Heat advisories and Extreme Heat Warnings remain in effect in many western and desert areas with several cities forecast to reach or near 100°F on Sunday.
- The Storm Prediction Center places parts of the Midwest and Great Lakes in Marginal-to-Slight risk for Monday–Tuesday with damaging winds, large hail and heavy rain the primary threats.
- Monsoonal moisture is producing daily afternoon thunderstorms over the Sierra and Southwest through early week, creating a heightened lightning-driven fire-start risk in dry fuels.
- Models and local forecasts show a trough and frontal passage by mid‑to‑late week that should widen storm coverage, raise the chance of training slow-moving storms and cause isolated flash flooding while temperatures ease.
- Active wildfires in the Northwest continue to send smoke that degrades air quality downstream and the National Hurricane Center is tracking two Atlantic tropical waves with roughly 20–40% short‑term development chances.