"This storm’s record-breaking sea-level pressure readings and ferocity will be studied in academic and operational spaces across the weather industry," writes the Chronicle's meteorologist Gerry Diaz. "While it’s not unheard of to have storms like this one rapidly intensify, it is unusual to see it occur just a few miles off the shoreline."
Yes, Tuesday's bizarre, hurricane-like windstorm took everyone, include those whose job it is to predict the weather, by surprise. SFist noted the eye of the cyclonic storm heading directly for San Francisco Tuesday afternoon, and it turns out this was one of two swirling eyes which spun off from each other over Monterey Bay — one made landfall here and on the Peninsula, the other hit the Santa Cruz coast.
"Meteorologists watched on radar as two areas of circulation formed just off the Monterey Peninsula," Diaz writes. "The Fujiwhara effect — when two circulations spin around each other — was in full effect by midmorning over Monterey Bay."
ABC 7 meteorologist Drew Tuma called the storm's behavior "unprecedented," noting that the barometric pressure dropped to 984.4mb, beating the monthly record, which was 990.2mb. "We've never experienced a March storm as strong as the one we just went through," Tuma said on Twitter.
And the San Diego-based Center for Western Weather and Water Extremes said that a double-eyewalled storm like this "likely won't ever happen again in our lifetimes over coastal CA."
Extraordinary radar imagery of yesterday's coastal storm w/ two centers of rotation combining at landfall over San Fran to produce banded rainfall and strong winds. While likely not w/o precedent globally, this likely won't ever happen again in our lifetimes over coastal CA. https://t.co/KKzojswC6v— CW3E Scripps (@CW3E_Scripps) March 22, 2023
Some 700 trees came down in San Francisco alone, and the storm resulted in at least five deaths locally, all from falling trees.
Meteorologists say that Fujiwhara effect storms like this occur globally, but they are rare and beyond rare for our coast. "In most instances, the centers of winter storms either stay out at sea or make landfall in remote stretches of the Oregon and Washington coast, keeping the strongest winds away from populated areas," the Chronicle's Diaz writes.
Also, while we may not see something quite so intense, we should all brace for more wet and windy weather early next week. Per Diaz, "The unusual weather may persist for another week or two, as the European and American models once again suggest that a couple of low-pressure systems off the coast of Hawaii tracking east toward California."
Top image: A tree down outside 1030 Post Street, where one person was killed on Tuesday. Photo by SFFD PIO