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Smoke Call Status:   Mon thru Fri excluding holidays
Issued: 12:30 PM   Tuesday, October 21, 2025
Discussion - Wednesday & Thursday
Weak Cut Off Low will brush southern portions of the region on Wed with Ridging influences elsewhere and regaining control over all of N. CA on Thu. Mixing heights will generally be higher on Wed compared to Thu but near to a little above seasonal levels are anticipated. Transport winds will be more variable with a slight increase anticipated on Wed, especially across the Greater Bay Area with lesser lighter speeds on Thu. Afternoon ventilation will be variable with generally poor to moderate levels and some locally good readings. Overnight inversions will be fairly strong. Some light showers could impact mainly the N. Sierra on Wed. 
Transport winds
Mixing Heights
(mph) (ft AGL)
Wednesday Afternoon Wednesday Afternoon
Wednesday Night Wednesday Night
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Transport winds
Mixing Heights
Thursday Afternoon Thursday Afternoon
Extended Outlook:  Friday - Sunday
Ridge break-down expected Fri thru Sun due to an active Jet Stream pattern. Transport winds will noticeably increase from a southerly and westerly direction during this period but especially favoring Fri & Sat. Outside of the heavier precipitation which is expected in areas, mixing should be above seasonal levels. A clean-out event is likely during this period with weaker overnight inversions. 
Helpful Resources:
Air Resources Board
San Joaquin Air Quality
AirNow Fire and Smoke Map
North Zone Predictive Services Weather Page
South Zone Predictive Services Weather Page
NWS California Fire Weather Page
NWS Spot Forecast Request
This Product was developed by the Predictive Services group, located at the North Zone Coordination Center in Redding, California