Warm and dry conditions with periods of breezy winds. Gusty north winds late this week will bring elevated fire weather concerns. Above normal temperatures into the weekend with Valley highs in the 90s.
Discussion
Clear skies cover interior NorCal early this morning as the area of high clouds associated with Sunday’s short-wave has pushed east of the area. Surface pressure gradients remain mostly onshore, and a moderate Delta Breeze continues with gusts around 20 mph at Travis AFB (and locally up to 15 mph elsewhere across the southern 2/3rds of the Sacramento Valley).
Warm and dry conditions will continue this week under high pressure. Temperatures will cool a bit today compared to the weekend, but will still be around 5 degrees above average. Warming returns Tuesday and Wednesday as highs return to around 10-15 degrees above normal.
The main forecast concern centers on the trough moving through the PacNW later this week. Ensembles and clusters indicate the tail end of the trough will dig into the Great Basin with tightening north and east surface gradient over NorCal in its wake resulting in breezy north to east winds and low RH leading to elevated fire weather conditions.
Extended Discussion (Friday through Monday)
Trough building south into the Great Basin will keep north winds elevated Friday. The ECMWF EFI still shows anomalous winds occurring over the Valley during this timeframe, bringing the potential for increased fire weather concerns. Latest guidance indicates wind gusts ranging from 20 to 35 mph with the strongest winds peaking Thursday night through Friday morning.
Ensembles and clusters show the trough exiting into the Plains Saturday with gradients and winds diminishing. Then, a ridge rebuilds over NorCal with dry weather and a warming trend. Daytime temperatures are expected to be 10-15 degrees above normal.