August 31, 2020 – Smoke and haze from wildfires will continue to impact air quality and temperatures for the next several days. Dry weather expected with much above average temps. Local north wind early this week.


Clear skies cover the region early this morning other than the widespread smoke that continues. North/northeast surface pressure gradients are gradually tightening and we’re beginning to see a few northerly gusts in the teens across the foothills and mountains surrounding the northern Sacramento Valley. The marine layer is holding steady around 1500 ft and a relatively light Delta Breeze continues at Travis AFB.

High clouds out ahead of the short-wave dropping down from BC are beginning to move into far northern California, but are thinning as they do. Moderate north winds will develop in the northern Sacramento Valley today as the short-wave drops south through the northern Rockies. The Delta Breeze will be strong enough to continue lighter flow from the coast into the southern portion of the forecast area. The north valley will likely see triple digit heat again today as the north winds shift deeper smoke to the south allowing for greater insolation. Further south, thicker smoke will likely inhibit greater warming across the southern Sacramento Valley and northern San Joaquin Valley.

Ridging from the eastern Pacific builds into NorCal on Tuesday with breezy northerly winds continuing in the Sacramento Valley. Triple digit heat is expected across the northern half of the Sacramento Valley. Ridge moves overhead Wednesday and Thursday with stronger inversions expected to result in greater smoke accumulation through the Central Valley which may help to moderate temperatures slightly, though triple digit heat is expected to continue for the north end of the Sacramento Valley.

Extended Discussion (Friday through Monday)

596 DM upper high over the Great Basin Friday continues to build through the weekend, then move over NorCal Monday. This will result in a warming trend through the extended with record breaking heat possible Sun/Mon as 850 mb temps rise into the lower 30s deg C. Dry weather expected through the extended forecast period.