August 14, 2019 – Dry weather will prevail through the week. A warming trend builds through Thursday with valley highs reaching triple digits. Cooler weather returns for the weekend. Excessive Heat Warning from 11 AM this morning to 10 PM Friday.
Discussion
Clear skies cover the region early this morning. Current temperatures range from the mid to upper 40s in the colder mountain valleys, to the upper 60s to around 80 across the Central Valley.
Strong high pressure will build across the region today and Thursday resulting in sunny skies and hot weather. The marine layer will continue to be suppressed with little or no relief from the Delta Breeze expected. Thursday will likely be the hottest day of this heat episode with highs in the valley forecast to range from 105-110, and some daily records may possibly fall. Overnight lows in the valley will also be mild with readings in the mid 60s to mid 70s.
High pressure will weaken slightly heading into the weekend which will allow a cooling trend to develop as onshore flow strengthens. It will still be hot on Friday with widespread triple digits through the Central Valley, but more substantial cooling is expected over the weekend.
Extended Discussion (Sunday through Wednesday)
Cooling trend continues into Sunday, with daytime highs in the upper 80s to low 90s across the Valley, and upper 60s to low 80s over the mountains. Then, a gradual warming trend is expected across interior NorCal early next week into midweek as upper ridging over the Desert Southwest builds westward. Forecast highs are expected to be near or within a few degrees of normal, with mostly mid to upper 90s in the Valley by midweek.