October 30, 2019 – Fire weather concerns today with breezy and dry conditions. Dry weather for at least the next week with temperatures warming to a little above average by the end of the week.
Discussion
Clear skies cover the region early this morning. Breezy northerly winds continue along the western edge of the Sacramento Valley with local gusts of 30-40 mph along the foothills. Across the northern Sierra, gusts of 25-45 mph continue with local gusts above 60 mph being reported near the mouth of the Feather River Canyon. Surface pressure gradients remain rather tight (KMFR-KSAC around 6 mbs while the KRNO-KSAC is 10 mbs), but have eased slightly compared to Tuesday evening.
Current temperatures are considerably milder across the windier portions of the area with lower to mid 50s being reported along the west side and north end of the Sacramento Valley. Wind sheltered mountain valleys are frigid with current readings in the teens. Some patches of frost will be possible along the eastern edge of the Central Valley to the southeast of Sacramento around sunrise where winds are light and enough moisture lingers.
Winds will gradually decrease today, but the extremely dry air mass will remain and red flag conditions are likely to persist into the afternoon. Much lighter winds Thursday and Friday, but still very low humidity values. High temperatures will warm each day with Valley readings reaching the low to mid 70`s by Friday. Some patchy frost will be possible in the valley tonight before temperatures gradually moderate later in the week.
Extended Discussion (Sunday through Wednesday)
A broad upper ridge sitting over the eastern Pacific and west coast will dominate the weather pattern through the middle of next week. While this supports continued dry weather, weaker pressure gradients will keep winds on the lighter side. Due to subsidence under the ridge and dry airmass, relative humidity values will remain quite low both day and night and this will keep at least some elevated fire danger in the forecast through this extended forecast period. Daytime highs will remain a few to several days above normal under the warm airmass and fair skies. These fair skies will allow overnight lows to drop to a bit below normal. Models are indicating the development of an upper low off the Socal coast towards the end of next week but at this time impacts on the CWA are expected to be minimal.