Unusually dry air is forecast to reach the Bay Area this week, bringing warmer weather and increased fire danger in some areas. The Northern California Geographic Area Coordination Center described the incoming air mass as unusually dry.

Northeast winds higher in the atmosphere are expected to draw continental air over Northern California. As winds descend from the Sierra Nevada, the air will warm, with temperatures forecast to rise from the 70s on Tuesday into the 80s and 90s by Thursday. Parts of the Bay Area and the Sacramento Valley could reach the 90s.

Away from the coast, relative humidity is forecast to fall below 20% on Wednesday afternoon, with Thursday expected to be hotter and drier. Weaker Diablo winds are expected in the Bay Area through the end of the week; morning gusts in the Oakland and Berkeley hills could exceed 25 mph.