Off-shore winds and generally dry, drought-y conditions mean heightened wildfire danger this weekend, and the National Weather Service (NWS) has issued the first Red Flag Warning of the new fire season.
The warning begins tonight, Friday, at 11 p.m. and extends until Monday at 6 a.m. The NWS is calling this a "moderate" offshore flow combined with low humidity, and while this could make for a couple of good beach days in San Francisco, it means wildfire danger for much of the Bay Area. The Red Flag warning has been issued for the North and East Bay hills, as we well as the inland valleys of the East Bay.
"The initial burst of dry offshore winds will reach the Napa county hills around 11 p.m. Friday night and then spread across the East Bay overnight into early Saturday," says the NWS. "These winds will usher in much drier air along with wind gusts in excess of 50 mph above 2000 feet."
Saturday will bring breezy conditions, and temperatures should be in the mid- to high 80s inland, both in the North Bay and East Bay.
"This pattern will help to rapidly dry out the fine fuels through the weekend," says the NWS. "There may be some moderate humidity recovery Saturday night but warm and dry weather persists Sunday with continued dry northerly winds and warm temperatures that will allow for rapid fire spread on any new ignitions, especially in the grass and dry brush."
Everyone is being advised not to light matches or cigarettes near dry fuels, and to be extra careful with barbecue grills and any outdoor flames. Also, wildfires in recent years have been sparked by things as simple as hammering spikes, dragging tow chains, and chainsaws striking rocks. All of that should be avoided.
A warming & drying trend will return this weekend with the development of offshore flow across the interior. This dry, breezy offshore flow will result in near critical fire weather conditions across portions of the Bay Area. https://t.co/yEnrNE8qjk #CAwx #BayAreaWX #OneLessSpark pic.twitter.com/9aodTe5Uk0— NWS Bay Area (@NWSBayArea) May 7, 2021
There's no word yet on whether this wind event will prompt PG&E to do any power shutoffs.
Photo: David Clode