Smoke Call Status:

Everyday due to ARA dispatch

Issued:

12:30 PM   Wednesday, September 17, 2025

Discussion - Thursday & Friday

Dynamic transition to the weather pattern will occur on Thu & Fri due to remnant tropical moisture flowing northward and interacting with a Low-Pressure system. Both mixing heights and transport winds will be variable due to the pattern change. Mixing heights have the potential of lowering a fair bit on Fri depending on where the rainfall occurs. Thu is more of the transition day with areas of steady to stronger transport winds with difference directions but primarily of the onshore variety. Ventilation is likely to be higher on Thu compared to Fri but not really seeing a strong stagnation signal since precipitation will be involved.

(mph)

(ft AGL)

Thursday Afternoon

Thursday Afternoon

Thursday Night

Thursday Night

Click on images to enlarge

Friday Afternoon

Friday Afternoon

Extended Outlook:

Saturday - Monday

Some initial Low-Pressure influences and remaining convection is expected on Sat before some sort of Ridging impacts the area Sun into possibly Mon. Overnight inversions should increase in strength while afternoon mixing increases overall. Transport winds will be a bit more variable and generally from a southerly or westerly direction. Stagnation is not likely although lesser ventilation should be found within the Sac Vly on Sun and possibly Mon.

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