Dry and breezy at times with seasonal temperatures. Fire weather concerns today, decreasing by this weekend. Hazy and locally smoky skies are likely due to area wildfires. Red Flag Warning in effect through Thursday evening 8:00 pm.
Critical fire weather conditions are impacting the region early this morning. As of 3:30 this morning, gusts of 20 to 30 mph are being reported in the Northern Sacramento Valley. Gusts to 40 mph have also been observed along the western side of the Sacramento Valley. Very dry conditions are also widespread across the Northern and western Sacramento Valley region with relative humidity values of 13% to 29%. Current surface pressure gradient from MFR to SAC is 10.9 mb.
Winds are forecast to increase across much of interior Northern California today, accompanied by very dry conditions. However, areas near the wind sheltered foothills and San Joaquin Valley could see less wind. Smoke will likely be transported by the wind from area wildfires and blanket much of Northern California through the day. High temperatures will likely be reduced by the smoke cover with some valley locations possibly only getting into the 80s. The low pressure system responsible for the increased winds will slowly shift eastward and as it does we will see the areas impacted by the strongest winds shift as well. The SAC to RNO gradient is forecast to reach about 8.5 mb overnight tonight leading to some increased winds over the Sierra as gusts in the valley start to decrease. We will see lingering breezy conditions Thursday with fire weather concerns continuing to decrease into this weekend as the low continues to head east.
Ensemble guidance is in good agreement we will likely be under continued troughing over the West coast and see increasing onshore flow this weekend. Humidity values will increase as well as the wind shifting to westerly/northwesterly aloft. This pattern will keep the region dry with periodically breezy winds. We will likely see a delta breeze as well as improved smoke conditions.
Extended Discussion (Sunday through Wednesday)
We are going to see quiet weather for the extended period as troughing remains in place over the west. This will keep seasonal temperatures in place with locally breezy onshore winds. Troughing slowly progress north into the middle part of next week with the upper level ridge starting to build back in. This will bring a warming trend the area.