July 19, 2017 – Warm and dry through the week. Locally breezy winds possible the next several days. Hot temperatures return for the weekend.
Skies remain clear across interior NorCal early this morning. Smoke moving north from the Detwiler Fire is moving across the far southeast portion of the forecast area. Current temperatures range from the 40s to lower 50s in the mountain valleys to the mid 50s to around 70 elsewhere.
Very little change expected across the region today and Thursday as dry southwest flow continues. Highs may bump up a few degrees in the Delta Breeze influenced areas as the marine layer fluctuates, but areas further inland won’t see much change the next couple of days.
The southwest ridge is forecast to extend westward again Friday into Saturday which will lead to another warm-up.
Extended discussion (Sunday through Wednesday)
Temperatures trend upward for the weekend, with widespread triple digit highs in the Valley and lower foothills. Record highs are not expected at this point, though, and the heatup will be brief. Temperatures peak Saturday, then trend downward to more average levels early next week as broad troughing moves in.
Models are showing a shortwave passing through Norcal this weekend into Monday. This varies from previous runs of the GFS which had a stronger closed low, further to the south, which would have brought the potential for elevated thunderstorms over the Sierra. The forecast for interior Northern California now looks generally dry, except for far northwest Shasta County Monday afternoon, where a few showers or thunderstorms are possible.