September 4, 2018 – Warm and dry weather continues this week. Areas of smoke and haze from wildfires will persist.
Discussion
Clear skies across the region early this morning. Current temperatures vary from the 40s in the mountain valleys to the upper 50s to lower 70s across the Central Valley and Sierra thermal belts. Weak upper trough will linger today with temperatures expected to be similar to those of Labor Day. Isolated late-day thunderstorms will be possible in the Sierra south of Lake Tahoe. Warm and dry conditions will prevail across interior NorCal the second half of the week. Highs will be around 5-10 degrees above average. Areas of haze and smoke will continue to affect the region, especially near wildfires.
Extended Discussion (Saturday through Tuesday)
Upper trough moves through PacNW Saturday, suppressing EPAC upper ridge and providing minor synoptic cooling over Interior NorCal. Models continue to show differing solutions Sunday into early next week. GFS rebuilds upper ridge, while EC brings additional Pacific short wave troughs inland. Forecast attm leans towards GFS with temperatures trending up Sunday into Tuesday.