For residents recovering from a record heat wave in a season typically marked by grueling wildfires and prolonged drought, the rain brought surprise and relief, along with a fair share of panic. In downtown San Francisco, the showers came in a flurry, breaking out around 9:45am. and they sprayed hard enough, within minutes, to rattle the tin chimney caps of apartment buildings. By 10 a.m. the rain had washed leaves into the drains and was threatening to clog them and begin to form ponds at intersections. A storm that produced weeks of tantalizing predictions had finally arrived. Then, by 10:15 a.m., it was over, another illustration of California’s extreme weather vicissitudes, where atmospheric rivers follow long periods of drought. At 11am the wind started howling and the rain started again. Organizers have canceled the annual LeatherWalk in SoMa, the Stern Grove Festival and Sunday Streets in the Western Addition. Bad weather delayed Flower Piano, a popular performance festival in Golden Gate Park, by an hour, though the evening continued at 11 a.m. with stages covering all twelve pianos. “The crowd is smaller than it would be on a sunny day, but there is an amazingly dedicated group of pianists and listeners who are here wearing their best raincoats, rain boots and umbrellas,” said Brendan Lange, spokesman for Flower Piano. Yasmin Bahl started her regular run on the steps of Lyon Street in torrential rain on Green Street. By the time he reached the top of Broadway, the rain had cleared enough to see a lone sailboat in the gray slate bay. “We closed our eyes. It’s over,” he said of the storm, before launching into the second of 10 sets on the steps. Light showers that drenched the pavement around 8 a.m. in the East Bay turned heavy in the afternoon when the rain came down in sheets. By then the storm had engulfed much of the North Bay, where forecasters predicted the mountains could see up to 3.5 inches of rain. Strong winds blowing south along the coast prompted the National Weather Service to issue an advisory for Sunday and warn of possible outages. “We certainly see this as a welcome rain event that will bring moisture to some of our dry fuels,” said Brooke Bingaman, a meteorologist with the National Weather Service. Although the storm’s behavior may appear erratic, Bingaman and other weather scientists expect it to produce unusually high levels of precipitation. Southerly winds gather over the Bay Area Saturday night, with rain forecast for the entire area Sunday night into Monday morning. National Weather Service Bay Area In downtown San Francisco, residents should expect about an inch, about four times more than the city collects in mid-September, Bingaman said. Amounts so far vary from a few hundred to 0.13″ Sonoma and Marin counties. A few raindrops already in San Francisco in the last hour, more arriving from the southwest. Surface to upper low still rotating (strengthening) ~ 200 miles west of Point Reyes. #CAwx pic.twitter.com/8VM6V9tr06 — NWS Bay Area (@NWSBayArea) September 18, 2022 Oakland should expect between half an inch and 0.75 inches of rain, possibly double the September rain average, he added. Forecasters expect similar totals in the San Jose area, which may also double the September average. “But it’s another case where North Bay is the winner for the rain,” Bingaman said. Sonoma and Napa counties will get 1 to 2 inches of widespread rain that began hitting the North Bay valleys Saturday night, hitting Mount Tamalpais and Mill Valley, the National Weather Service said, as winds picked up in the East Hills. Bay and the Santa Cruz Mountains. Commuters should expect a messy drive Monday morning, Bingaman said, as the first rain of the year mixes with oil slicks on Bay Area roads, creating dangerous conditions, along with strong winds blowing debris onto roads. Winds could also blow tree limbs onto power lines, causing outages. In addition, the first rains can turn accumulated dirt on power lines into mud, which carries electricity and can damage the system and cause outages. Fortunately, Bingaman said, the burn scars in the bay area are older, so she doesn’t expect mudslides in the area. In the Lake Tahoe area, light snow is possible at higher elevations, National Weather Service meteorologist Zach Tolby said. But the biggest impact should be cooler temperatures, windier conditions and about an inch of rain across the region. Tolby said residents are finally getting a reprieve from the smoke. “The mosquito fire has gone up in smoke,” he said. “Well, we’re all very excited to see some wind, rain and clouds.” Matthias Gafni and Rachel Swan are San Francisco Chronicle staff writers. Email: [email protected], [email protected] Twitter: @mgafni @rachelswan
