Weather forecast for northern California

Smoke will be another issue this morning, limiting the daytime heating and surface winds during the afternoon hours. However, later this evening and tonight winds will pick up across the far Northern Sacramento Valley and adjacent foothills. These winds will be from the N to NE at 10-20 mph across many exposed areas, along with poor nighttime humidity recovery.

Some areas in the Feather Drainages could see gusts over 35 mph late tonight thru Friday morning. Afterwards, by Friday afternoon all eyes will be on the next thunderstorm outbreak, moving in from the Sierra and shifting NW into much of Northern California through the weekend. Many of these storms could be dry.

(the above, and some of the information below, is from North Ops Predictive Services, 1900, June 25)

What this means for fire behavior-
Since Sunday June 22 the stable atmosphere has not only produced inversions that trapped smoke, but it also slowed down fire behavior due to the resistance to vertical motion and shading from the smoke. When this begins to change Thursday afternoon and Friday there could be a gradual change in venting, and an increase in fire behavior. But in some situations, a major change in rates of spread could occur in as little as 1-2 hours.

What this means for firefighters-
Smoke will lift earlier in the day allowing more options for air operations, and surface winds could become stronger. EXPECT changes in fire behavior. Have lookouts observe changes winds, visibility, and smoke behavior, such as gentle lifting changing to more rapid rising of smoke and faster growing columns.