Chilly morning with a chance of ghosts and goblins tonight

October 31, 2019 – Dry weather through the extended period. Daytime temperatures a few to several degrees above normal with warmest temperatures early next week. Overnight lows slightly below normal.

Discussion

Under lighter wind conditions, early morning temperatures are several degrees cooler than 24 hours ago most locations. Some valley locations were already seeing temperatures in the 30s during the early morning hours. A large upper level high pressure ridge over the eastern Pacific and west coast will dominate the Norcal weather pattern through the short term forecast and beyond. The next several days will see fair skies and above normal daytime temperatures with clear skies bringing a little below normal low temperatures over nights. Daytime highs will run just above normal today with a slow warming over the next few days climbing to around 5 to 8 degrees above normal season values by Sunday. The warm temperatures and dry airmass will keep daytime humidity low with only poor to moderate overnight humidity recovery expected. Therefore, fire weather conditions will remain elevated going in to the weekend.

Final Note…This will be my last Area Forecast Discussion as I am retiring after a 33 year career with the National Weather Service, mostly working the night shift. Thanks for reading. -Mike Smith <— Thank you Mike!

Extended Discussion (Monday through Thursday)

Dry conditions and seasonably warm temperatures are expected for interior NorCal throughout the extended forecast period. Upper level ridging will remain situated over the eastern Pacific, allowing daytime temperatures to rise above normal. The dry airmass along with subsidence under the ridge will keep daytime relative humidity levels very low as well as poor overnight recoveries. Fuels have dried significantly over the past two weeks due to the multiple dry northerly wind events. The low humidities and dry fuels will keep fire weather conditions slightly elevated through next week. Clear skies over the area will allow overnight temperatures to fall to near or slightly below normal. Ensemble models continue to hint at an upper level low developing off the Southern California coast, but current model runs keep the low well south of the forecast area. Impacts are expected to be minimal at this time, with conditions remaining dry and winds becoming slightly breezier.