The National Weather Service in Sacramento has forecasted a reprieve from the recent sweltering temperatures seen across Northern California. With a shift of high pressure eastward and a weak trough developing along the coast, Californians are expected to see "less hot weather" through the middle of this upcoming week. Highs in the Central Valley are predicted to hover into the mid-90s to low 100s, offering a minor to moderate HeatRisk—a welcome change from the blistering heat that held the region firm in its grip.
On the horizon, however, is a potential weather disturbance. Elevated monsoonal moisture is currently streaming over the state, increasing the likelihood of thunderstorm activity, particularly along the Sierra Crest. Due to dried fuels from the previous heatwave, there is an elevated risk for lightning-induced fires. Consequently, the National Weather Service has decided to simultaneously actively monitor and issue a Red Flag Warning for Sierra Fire Zones 221 and 269 above 6000 feet, as well as for the Coastal Range Fire Zones 213, 263, 279, effective through this evening.
While the weekend may bring isolated mountain showers, the start of the week looks to bring some stability, with thunderstorm chances reducing to 10-20% along the Sierra crest south of I-80. The Delta area can expect to feel the effects of an enhanced breeze ushered in by the increased onshore flow, which should aid in the cooling effort with gusts reaching 20-30 mph at times in the afternoon and evening hours.
Looking towards the later part of the week, interior Northern California is bracing to once again be caught between a weather system tug-of-war. The area is forecasted to be sandwiched between upper troughing to the northwest and an upper high over the Desert Southwest. As a result, temperatures are expected to climb, with the possibility of triple-digit heat becoming more widespread over the Central Valley by the weekend. "Widespread moderate with areas of major heat risk expected," warns the National Weather Service. Aviation conditions meanwhile are predicted to remain VFR with some possibility of isolated mountain thunderstorms continuing tomorrow.
