September 3, 2018 – Warm and dry weather continues this week. Areas of smoke and haze from wildfires will continue.
Discussion
Clear skies across interior NorCal early this morning other than a few high clouds across the far northern portion of the state and some stratus extending locally inland from the coast. Current temperatures range from the 40s in the mountain valleys to the upper 50s to around 70 across the Central Valley and Sierra thermal belts. Little change expected the next several days with warm and dry conditions continuing with temperatures around 5-10 degrees above average. The marine layer has deepened slightly to around 2k feet, and onshore gradients have tightened a bit, so highs may be down a bit today in the Delta and locally across the Sacramento region. Potential for convection exists in the Sierra south of Tahoe into mid-week, but will likely be quite isolated and limited to the late-day hours.
Extended Discussion (Friday through Monday)
Upper low approaches the PacNW Friday, weakens and moves inland Saturday. This will suppress EPAC upper ridging and provide synoptic cooling with increased onshore flow. Models differ Sunday into Monday with GFS rebuilding upper ridge, while EC brings another system through the PacNW. Forecast attm trends towards GFS with temperatures trending up Sunday to slightly above normal Monday.