A rapidly intensifying cyclone brought high winds to the region. A High Wind Warning was issued for the San Mateo Peninsula Coast, the Santa Cruz Mountains, and the Central Coast.
Every event with a place to put it; 22 filed by county or forecast zone are drawn at its center, in a lighter ring. Tap one for its entry below.
Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
The episode as NWS MTR wrote it up.
A rapidly intensifying cyclone brought high winds to the region. A High Wind Warning was issued for the San Mateo Peninsula Coast, the Santa Cruz Mountains, and the Central Coast. In addition, a couple of Severe Thunderstorm Warnings were issued in light of the expected extreme winds for the Monterey and Santa Cruz areas. Over 110,000 customers lost power throughout the Bay Area and Santa Cruz County as a result of the cyclone.
The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS San Francisco Bay Area, CA wrote its last area forecast discussion before the first event at Mar 21, 3:24 AM PST, 3 hours 16 minutes earlier.
Area Forecast Discussion
National Weather Service San Francisco Bay Area
424 AM PDT Tue Mar 21 2023
.SYNOPSIS...A strong Pacific storm system will move into the
central California coast on Tuesday. High winds and widespread
rainfall are expected, along with possible thunderstorms from
around the Monterey Bay region southward. High Wind Warnings have
been issued for all of Monterey and San Benito counties and now
also northward along the coastal strips of Santa Cruz and San
Mateo counties as well as over the Santa Cruz Mountains. San
Francisco and all of the East and South Bay are under Wind
Advisories. Showers look to continue Tuesday night along with the
continuing possibility of a thunderstorm, then taper off from the
north Wednesday afternoon and evening. Cool and mostly dry
conditions then appear on tap for the latter part of the week and
into the weekend.
&&
...Very strong Pacific storm system to bring wind and rain impacts
Tuesday...
.DISCUSSION...as of 03:00 AM PDT Tuesday...Latest model guidance
is in very good agreement on rapid cyclogenesis underway off our
coast. Really wish there was something by way of surface obs out
there, but presently/recently no ship of opportunity reports (and
likely for good reason given the developing weather conditions).
High-resolution consensus has now shifted southward a bit with
the track of the surface low, bringing it into the coast in the
vicinity of Pigeon Pt late Tuesday afternoon rather than up near
the San Francisco Peninsula. The projected central pressure has
also moderated just a tad, but still way down in the 985-990 mb
range and if bears out would be among the lowest ever here for the
month of March.
It appears two bands of especially strong winds, extending out
like the arms of a pinwheel, will rapidly move through from off
the Big Sur coast: the first (essentially the warm front) Tuesday
morning and the second (the cold front) Tuesday afternoon.
Highest wind speeds in both cases look to be focused over the
southern half of our district, with highest gusts in windiest
locations potentially reaching up into the 65-75 mph range.
Impacts could be substantial, with yet a lot more downed trees,
power outages and blocked roads.
Accompanying rain looks to be heavy at times, especially over the
Santa Lucia Mountains and Santa Cruz Mountains where maximum
rainfall totals by 12Z Wednesday are forecast to get up to around
6-7 inches and 4-5 inches, respectively. Corresponding lower
elevation rainfall totals look to be in the 0.5-1.0 inches range
in the North Bay, 0.75-1.25 inches heart of the San Francisco Bay
Area, and 1.0-2.0 inches in the Monterey Bay region. Do not
presently expect any rivers or streams to reach flood stage, but
can't entirely rule out the possibility of flash flooding and or
mudslides/debris flows, with primary concern over the coastal
slopes of Big Sur which WPC has placed in the Slight Risk category
in its latest Excessive Rainfall Forecast for 12Z Tues - 12Z Wed.
Will also note that USGS research instrumentation indicates that
across the CWA shallow soils on steep hillsides are approaching
saturation -- and therefore the possibility of shallow landslides
exists if and where rainfall rates and intensities become
sufficiently large.
Also want to note that thunderstorm chances develop Tuesday
afternoon and evening, primarily from the Monterey Bay region
southward. With 500 mb temps then projected to lower to around 30
deg C, surface based CAPES look to locally get up into the
500-700 J/kg range. Given the projected accompanying strong lower
tropospheric vertical wind shear, can't rule out the possibility
of a waterspout, or local spinup over land, and will need to
carefully monitor the radar. Small hail could also well occur.
Showers look to taper off from the north Wednesday afternoon and
evening with mostly dry conditions prevailing districtwide by
Thursday morning. Cool and mostly dry weather then looks to
prevail through the end of the week and into the weekend, though
can't entirely rule out the possibility of a few showers at times
as large-scale flow remains moist and out of the northwest.
Friday night and then Saturday night especially, overnight
minimum temperatures are forecast to get unseasonably chilly. This
is of particular concern in the Wine Country of the North Bay
where "bud break" has now begun in the vineyards and lows look to
then potentially reach to freezing or below. Will continue to
monitor as the time frame approaches as freeze/frost products
could well end up being needed.
In the extended, new 00Z GFS, ECMWF and Canadian Ensemble
solutions indicate yet another unseasonably deep upper level
trough developing off the California coast the first part of next
week, with another round of rainfall then appearing likely.
&&
.AVIATION...as of 4:24 AM PDT Tuesday..For the 12z TAFs..Easterly
and southeasterly winds are increasing as a strong surface low
approaches. This low pressure system will bring moderate to heavy
rain starting lasting through the afternoon with scattered showers
continuing through the evening and lingering into the night.
Expect MVFR CIGs for most of the TAF period. As the center of the
low moves inland, southerly winds will increase. Strong gusts of
35 to 40 knots possible across the region, primarily south of the
Golden Gate. Winds and rain chances begin to diminish into Tuesday
night.
Vicinity of KSFO...Rain with MVFR conditions are expected as the
next system enters the area. Winds will turn easterly in the early
morning ahead of the building rain. Winds shift southeast as low
moves inland and eventually become even more southerly into the
afternoon. Wind gusts become strongest between 20z and 04z with
gusts up to 34 knots (but potentially higher depending where low
sets up and will continue to monitor). Expect winds to reduce into
Tuesday night, but they will stay breezy until early Wednesday
morning.
SFO Bridge Approach...Similar to SFO.
Monterey Bay Terminals...Becoming MVFR. Southeast winds are
increasing and look to continue to gain strength through the morning
with 40 kt gusts possible. Moderate, to at times of heavy, rain will
accompany the increased winds. Rain chances as well as the elevated
winds begin to reduce into Tuesday night.
&&
.MARINE...as of 02:48 AM PDT Tuesday...A strong system is arriving
bringing gale force gusts to much of the waters and even storm
force winds south of Pigeon Point. Widespread rain also expected
overnight through Wednesday. By midweek, a west swell will
combined with wind wave will create high and steep seas. A long
period northwesterly swell also expected to arrive towards the end
of the week.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.Tday...Wind Advisory...CAZ006-508-510-513>515
High Wind Warning...CAZ509-512-516>518-528>530
SCA...SF Bay
SCA...Pt Arena to Pigeon Pt 10-60 nm
GLW...Mry Bay
GLW...Pigeon Pt to Pt Pinos 0-10 nm
SCA...Pt Arena to Pt Reyes 0-10 nm
SCA...Pt Reyes to Pigeon Pt 0-10 nm
SRW...Pt Pinos to Pt Piedras Blancas 0-10 nm until 9 AM
GLW...Pt Pinos to Pt Piedras Blancas 0-10 nm from 9 AM
GLW...Pigeon Pt to Pt Piedras Blancas 10-60 nm
&&
PUBLIC FORECAST: Blier
AVIATION: Murdock
MARINE: Murdock
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www.youtube.com/nwsbayareaThe national radar mosaic for the moment the first event began.
11 high wind, 11 strong wind. Local standard time, as filed.
The Highlands Peak weather station operated by the Desert Research Institute reported a wind gust of 75 mph.
The Funt Ranch weather station operated by PGE reported a wind gust of 61 mph.
The Santa Fe Geothermal weather station operated by PGE reported a wind gust of 59 mph.
The Monterey Regional Airport ASOS reported a wind gust of 59 mph.
The Younger Lagoon Reserve weather station operated by the Desert Research Institute recorded a wind gust of 60 mph.
A tree fell on California Highway 1 near Dolan Road in Moss Landing, blocking Highway 1.
A tree fell on a jogger at 23rd Avenue and Lincoln Way in Golden Gate Park in San Francisco. The jogger was sent to the San Francisco General Hospital, where they were pronounced dead.
A CWOP station near Boulder Creek reported a wind gust of 61 mph.
A tree fell on power lines near Glen Arbor Road in Ben Lomond, causing the communities of Ben Lomond and Boulder Creek to be cut off; the road was open by the next day but PGE crews were continuing to work on clearing debris.
Across the rest of Boulder Creek, dozens of trees fell on homes. The Boulder Creek Fire Department reported that one person was injured after a tree fell on their home, and by Wednesday afternoon, they were still unable to access some homes due to storm damage.
The KNPT Towers weather station operated by PGE reported a wind gust of 89 mph.
The Watsonville Airport ASOS reported a wind gust of 59 mph.
A tree fell onto a white van traveling eastbound near the area of Alpine Road and La Cuesta Drive just west of Interstate 280 in Portola Valley. CHP responded to the scene at 1:34 PM, cleared some large branches, and found a man dead inside. Alpine Road was closed west of Interstate 280 in both directions.
A person was injured after a tree fell on them near Ellis and Hyde Streets.
At 4:15 PM PDT the Golden Gate Bridge sensor reported a wind gust of 61 mph. Ferry service across the San Francisco Bay was cancelled due to high winds and surf starting around 2 PM and lasting through the rest of the day.
The Oakland Airport ASOS reported a gust of 74 mph.
The San Francisco International Airport ASOS reported a gust of 64 mph, causing the FAA to issue a ground stop for flights to the airport.
A tree fell and struck a vehicle, critically injuring a San Francisco Police sergeant inside.
Two people were injured when a tree fell on them near Post and Polk in the Nob Hill neighborhood of San Francisco. They were taken to the hospital where one of the people died.
A tree fell on an unhoused man in his tent near Lake Merritt in Oakland. Authorities pronounced him dead on the scene.
A big rig overturned on the Eastbound Bay Bridge (Interstate 80), blocking all the eastbound lanes for hours.
Industrial barges came loose and collided with the Third Street Bridge, damaging the bridge and forcing it to close.
A tree fell onto a car on the 1000 block of Stanley Dollar Drive in Walnut Creek, occupied by two residents of a retirement home. Contra Costa Fire responded around 7 PM and found the driver injured and the passenger dead at the scene. The road was closed as firefighters worked to clear the scene.
As the offices recorded each death: direct deaths were caused by the weather itself, indirect ones by something it set in motion.
| Event | Date | Age | Sex | Where | Kind |
|---|---|---|---|---|---|
| Strong Wind, San Francisco | 2023-03-21 | Female | Outside/Open Areas | Direct | |
| Strong Wind, San Francisco Bay Shoreline | 2023-03-21 | 29 | Male | Under Tree | Direct |
| Strong Wind, San Francisco | 2023-03-21 | 36 | Male | Under Tree | Direct |
| Strong Wind, San Francisco Bay Shoreline | 2023-03-21 | 63 | Male | Under Tree | Direct |
| Strong Wind, East Bay Interior Valleys | 2023-03-21 | 79 | Male | Under Tree | Direct |
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in California in 2023Every state in 2023This day in weather historyWarnings in California, March 2023
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 1087086, 1087080, 1087084, 1087073, 1087077, 1087088, 1086521, 1087079, 1087087, 1087083, 1087100, 1086656, 1087093, 1090916, 1087097, 1087098, 1087092, 1086659, 1086658, 1087091, 1087094, 1086657.