San Franciscans should fetch their umbrellas and brace for a damp weekend as forecasters from the National Weather Service in San Francisco, predict rain to return starting Friday night and into Saturday. "Wet, unsettled conditions returning Friday night and Saturday," the service notes, cautioning a much cooler weekend, especially inland, with daytime highs nosediving between 10 to 18 degrees Fahrenheit compared to Friday's temps, as detailed in the area's latest forecast discussion, which was published early Wednesday morning.
The weather shift comes courtesy of a cold front that's due to swipe through the region, "light to moderate rain on Saturday" is expected, the NWS website reported. While most of the Bay Area could see a quarter inch of rain, the coastal ranges might catch up to half an inch. Residents by the bay experienced similar conditions on Tuesday, dry with gradual warming, only to see a shift as nature scripted its capricious play, a hallmark of Bay weather, bringing in the rains and cutting short the stint of sunshine and moderate temperatures that had been slowly climbing during the earlier part of the week.
The transition will be marked by an incursion of a cold core low-pressure system from the Bering Sea and the Aleutian Islands, arriving in Northern California on Friday night. While traversing cooler than normal sea surface temperatures, this system is predicted to maintain its strength, aided by encountering a long wave trough on the West Coast. It is also set to brush past and draw higher levels of water vapor from north of Hawaii, "the low is forecast to move through our forecast area retaining a strong mid-latitude influence," per communications from the National Weather Service.
While weekend warriors on the bay might be looking at a soggy schedule, aviators and mariners have their concerns with which to reckon, "Breezy and gusty winds continue through Friday," says the National Weather Service's marine forecast, "with gale force gusts of 40 to 45 knots possible in the outer waters through much of the week," promising rough seas and high waves. A calmer sequence is predicted post-squall, with conditions expected to settle into next week, but this weekend, it’s the wind and rain that take the weather stage in the San Francisco Bay area, leaving its tranquil guise behind.
