Overview
- A strong upper-level ridge is keeping much of the interior West dry and unseasonably warm this week, with heat advisories and extreme-heat warnings in parts of Northern and Southern California through midweek and the potential for midweek record highs.
- Cold air and a brisk frontal passage have dropped overnight temperatures in the Northeast and Upper Midwest, producing widespread frost advisories and isolated freeze warnings that threaten sensitive late-season crops and gardens.
- Most of the country will remain sunny and dry through midweek because of the ridge, reducing near-term rain chances but increasing wildfire and outdoor heat exposure concerns in hot areas of California.
- Forecast uncertainty rises late in the week as a developing disturbance in the southwestern Gulf has a medium 7-day chance of tropical development and a Pacific trough or low may either deliver soaking rain to California or a sharp cooldown with early Sierra and northern Rockies snow.
- Local National Weather Service offices urge people to follow updates for heat safety, protect vulnerable crops from frost, and watch weekend forecasts closely because small shifts in storm tracks will determine whether moisture, coastal impacts, or an abrupt cooldown materialize.