Expect the Heat to Return to the Bay Area Monday and Tuesday

"San Francisco's first significant bout of "real summer" or "September summer" looks to be headed here on Monday, with the possibility of those unsettling offshore winds that leave the city feeling hot hot hot. You've got today's persistent marine layer to endure, and another weekend of morning drear and only slightly warmer afternoon temperatures possibly. But just in time for the workweek to begin, a heatwave is going to land in the Bay Area and last a couple of days,"

"Offshore winds, for those not in the know, are the opposite of what SF experiences 350-some-odd days of the year, and they happen when the wind begins flowing out of the East Bay and out to the ocean something that often results in SF's hottest days of the year, with our natural air conditioner, the ocean breeze, suddenly absent."

"Downtown SF and Oakland are expected to see a high in the 80s on Monday, but as the Chroncile notes, "If offshore flow dominates, both cities could make a run at 90 degrees Tuesday." The meteorologists note that a very similar pattern took hold on September 13, 2019, and Oakland and SF saw temps in the 90s that day. Other forecasts indicate that the sun and warm days will extend further into the week, and when these offshore wind patterns take hold"

A heatwave will arrive in the Bay Area starting Monday and will last a couple of days, with San Francisco included. Weather models predict an alignment that suppresses the daily sea breeze, compresses the marine layer and can flip winds offshore at low levels. Offshore flow pushes air from the East Bay toward the ocean, eliminating the usual ocean breeze and producing some of the hottest local days. Downtown San Francisco and Oakland could reach highs in the 80s on Monday and potentially near 90 degrees on Tuesday if offshore flow dominates. Similar conditions produced 90s on September 13, 2019.

Read at sfist.com