Valley highs will warm to the upper 80s in Butte County today and closer to the mid 90s for the northern tip of the valley floor. The chance for isolated mountain thunderstorms will be very small today.
The Northstate will continue to sit in northwesterly flow aloft through the rest of the week. The only notable system will be a trough diving into the Great Basin Friday night into Saturday. The "vorticity maximum" on the western side of the trough will clip the northeastern part of the Northstate. This is our typical "Inside slider" that we usually see in the spring and fall. The surface gradient will not be all that strong so northerly winds will have to be advected, mixed to the surface, which will limit hihg fire danger.
A ridge of high pressure will begin to build in by Sunday into next week. Parts of the valley floor will be back into the triple digits as early as Monday but likely closer to Tuesday or Wednesday.