An atmospheric river brought widespread high winds and rain, leading to significant damage, power outages, and injuries. High Wind Warnings were issued for the entire region, and over 180,000 customers lost electricity during the event.
Every event with a place to put it; 15 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.
An atmospheric river brought widespread high winds and rain, leading to significant damage, power outages, and injuries. High Wind Warnings were issued for the entire region, and over 180,000 customers lost electricity during the event. Impacts were compounded by an earlier system that resulted in widespread damage, some areas of the Monterey Peninsula lost power again after having lost power for days from the previous system.
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 14, 4:07 AM PST, 3 hours 38 minutes earlier.
Area Forecast Discussion
National Weather Service San Francisco Bay Area
507 AM PDT Tue Mar 14 2023
.SYNOPSIS...Atmospheric river to bring significant impacts to the
region today. Strong damaging winds, power outages, additional
flooding, and road closures are all anticipated. Avoid unnecessary
travel.
&&
.DISCUSSION...as of 03:07 AM PDT Tuesday...
Key Points--
* Moderate to strong Atmospheric River impacts the region today
* Direct threat to life and property from wind and water impacts
* Flooding of streets, creeks, and streams is expected
* Moderate to major impacts may occur from river flooding
* Flash flooding, debris flows, and shallow landslides are possible
in complex terrain
* Downed trees expected with widespread power outages possible
* Difficult to impossible travel for some areas due to road closures
The much advertised atmospheric river is taking aim on
the central California coast this morning with deep moisture
advection spreading inland at this hour. Rainfall so far this
morning has been light, generally a few hundredths of an inch per
hour or so. However, rain will increase in coverage and intensity
through the remainder of the morning as a strengthening surface low
approaches the northern and central California coast. As such,
southerly winds will strengthen to around at 25 to 40 mph with gusts
to 50 mph. Gusts of up to 70 mph are expected along the coast,
ridges, peaks and coastal gaps. Winds will be strongest between 4 AM
- 12 PM PDT and likely result in downed trees with the potential for
widespread power outages. With respect to the rain, the highest
rainfall amounts through the day will be in the coastal ranges and
inland hills with 2-3" totals from the Santa Cruz Mountains
northward and 3-6" in the Santa Lucia ranges with isolated amounts
up to 8" in the favored peaks. Elsewhere, look for 0.5-2" with the
greatest in the North Bay. The strong southerly flow with this
system will result in a strong rain shadow effect, especially in the
Salinas and Santa Clara valleys. Lastly, there remains a 10-20%
probability of thunderstorms this morning as the mid/upper level
dynamics increase, especially over the Central Coast. All this said,
the USGS soil moisture sensors across the Bay Area show conditions
overly saturated. This will result in rapid runoff only exacerbating
flooding concerns region-wide.
The latest guidance suggests this system will be quick moving with
precipitation tapering off from north to south by this afternoon.
Winds will also being to diminish in wake of the frontal passage,
yet will be breezy at times through the evening. That said, flooding
impacts are likely to continue as mainstem rivers rise potentially
into midweek. Remember, NEVER drive into flooded roadways! Turn
around, don't drown.
Drier conditions are looking more likely through the remainder of
the week with low probability (10-30%) of light precipitation this
upcoming weekend. The potential for more widespread rainfall
increases for the first half of next week, yet there remains a lot
of uncertainty at this time. Folks are urged to keep up-to-date with
the latest forecast information in the days to come.
&&
.AVIATION...as of 5:07 AM PDT Tuesday...For the 12Z TAFs. Expect
rapidly deteoriating weather conditions /LIFR-IFR/ with strong and
gusty winds, low level wind shear and heavy rain with a rapidly
approaching frontal band from the southwest this morning. Gusty
southeasterly surface winds developing, winds veering with height
(signature of warm air advection) to southerly and eventually
southwesterly prior to cold frontal passage early this afternoon.
Meso-scale models show upwards 70 knots of wind at ~ 2500 feet;
turbulence and downward momentum transfer likely bringing gusty
winds to the surface prior to cold frontal passage. If a silver
lining, the 500 mb trough is low amplitude and guided by swiftly
moving west to east jet stream winds, which brings the cold front
through the cwa quickly. Post cold front later today brings the
cwa back to the cooler air mass side with quickly diminishing
showers and winds. Drier air aloft tonight and Wednesday may
result in improving radiative cooling to space allowing patchy
late night and morning valley fog /VLIFR-IFR/ to develop.
Vicinity of KSFO...Rapidly deteorating weather conditions this
morning. Expect an increasingly strong and gusty southeast wind
developing along with moderate to heavy rain. Low level wind shear
developing as well lasting up until cold frontal passage forecast
to arrive 2030z today. Wind shifting to southwest to weste and
quickly easing thereafter with showers diminishing. MVFR ceiling
during the period. Light northwest wind tonight.
KSFO Bridge Approach...Similar to SFO.
Monterey Bay Terminals...Rapidly deteorating weather conditions
this morning. Expect increasingly strong and gusty southeast winds
along with moderate to heavy rain except northern Salinas Valley
rain shadowed including vicinity KSNS. Low level wind shear
developing lasting up until cold frontal passage forecast to
arrive 21z-22z today. Winds shifting to southwest and easing
quickly post cold front, southwest to west winds 5 to 10 knots
tonight and Wednesday morning. MVFR ceilings except locally IFR in
downpours.
&&
.CLIMATE...
Rain Records for some of our official Climate Sites
Climate Site March 14 Record
Santa Rosa 1.42" 1942
Kentfield 4.17" 2012
Napa dwntown 3.30" 2003
Livermore dwtn 0.88" 2020
SF downtown 1.68" 1952
Oakland dwtn 2.46" 2012
San Jose 1.40" 1952
Salinas arprt 1.01" 1948
&&
.MARINE...as of 03:07 AM PDT Tuesday...A moderate to strong low
pressure storm system with heavy rain and widespread gale-force
gusts arrives across the coastal waters tonight, with hazardous to
dangerous marine conditions continuing into Tuesday night.
Anticipate steep wind waves and a mixed swell system with
northwest and southwest components. Winds shift to the west and
the northwest Tuesday night, leading into a break in the rain
before winds turn southerly again Thursday night into another,
less intense, rain system comes through the weekend.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.Tday...Flood Watch...CAZ006-502>506-508>510-512>518-528>530
High Wind Warning...CAZ006-502>506-508>510-512>518-528>530
GLW...SF Bay
GLW...Mry Bay
GLW...Pt Arena to Pt Reyes 0-10 nm
GLW...Pt Reyes to Pigeon Pt 0-10 nm
GLW...Pigeon Pt to Pt Pinos 0-10 nm
GLW...Pt Pinos to Pt Piedras Blancas 0-10 nm
GLW...Pt Arena to Pigeon Pt 10-60 nm
GLW...Pigeon Pt to Pt Piedras Blancas 10-60 nm
&&
PUBLIC FORECAST: RGass
AVIATION: Canepa
MARINE: Murdock
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www.youtube.com/nwsbayareaPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SAN FRANCISCO CA
540 AM PDT TUE MAR 14 2023
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0531 AM FLOOD 3 ENE MARINA 36.70N 121.74W
03/14/2023 MONTEREY CA LAW ENFORCEMENT
WATER OVER THE RDWY / STEAD STREAM FLOWING.
FELT LIKE IT WAS PUSHING VEHS INTO THE
FIELD.
&&
EDPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SAN FRANCISCO CA
713 AM PDT TUE MAR 14 2023
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0712 AM FLOOD 2 ESE PETALUMA 38.23N 122.59W
03/14/2023 SONOMA CA LAW ENFORCEMENT
TREE DOWN BLOCKING ROAD WAY.
&&
EDPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SAN FRANCISCO CA
726 AM PDT TUE MAR 14 2023
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0710 AM FLOOD 4 SE DEL MONTE FOREST 36.54N 121.90W
03/14/2023 MONTEREY CA LAW ENFORCEMENT
TREE DOWN, BLOCKING HALF OF THE WB LANES.
&&
EDPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SAN FRANCISCO CA
735 AM PDT TUE MAR 14 2023
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0730 AM FLOOD 3 SSW SCOTTS VALLEY 37.02N 122.03W
03/14/2023 SANTA CRUZ CA LAW ENFORCEMENT
FLOODING BOTH SOUTHBOUND LANES AT EL RANCHO
/ LA MADRONA BRIDGE.
&&
EDPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SAN FRANCISCO CA
809 AM PDT TUE MAR 14 2023
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0330 AM NON-TSTM WND DMG 1 WNW SANTA ROSA 38.45N 122.71W
03/14/2023 SONOMA CA FIRE DEPT/RESCUE
TREE DOWN ON ORCHARD ST NEAR SPENCER AVE,
TAKING DOWN POWER LINES.
&&
DHPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SAN FRANCISCO CA
824 AM PDT TUE MAR 14 2023
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0824 AM FLOOD 2 S PORTOLA VALLEY 37.34N 122.22W
03/14/2023 SAN MATEO CA LAW ENFORCEMENT
MUDSLIDE COVERING BOTH LANES.
&&
EDThe national radar mosaic for the moment the first event began.
8 high wind, 7 strong wind. Local standard time, as filed.
The San Francisco International Airport ASOS reported a gust of 74 mph at 11:56 AM PDT. This resulted in a ground stop that paused airport operations, and a ground delay program.
The Road to Ranches station operated by PGE recorded a wind gust of 93 mph.
The Long Ridge station operated by PGE reported a wind gust of 68 mph.
The Lucas Valley station operated by PGE reported a gust of 90 mph.
The Umunhum South station operated by SJSU reported a wind gust of 97 mph.
The Cobb Ridge West station operated by PGE reported a wind gust of 74 mph.
The Mines Tower weather station, operated by PGE, measured a wind gust of 93 mph.
A tree fell onto Oak Avenue Elementary school in Los Altos, injuring a student.
The Monterey Peninsula Airport reported a wind gust of 51 mph. Across the Monterey Peninsula region, downed trees damaged 13 homes and closed California Highway 1 at the Point Lobos State Natural Reserve, California Highway 68 at the SFB Morse Gate, and other roads across the city of Pacific Grove. Southbound California Highway 1 was also closed at California Highway 68, or Holman Highway, due to downed power lines. On Highway 1, a man was injured when he stopped due to a downed tree and was hit by a second falling tree.
A fallen eucalyptus tree closed California Highway 92 near Half Moon Bay.
A tree fell on California Highway 9 between El Solyo Heights Drive and Brackney Road in Felton, taking down power lines and blocking the road.
One person was injured when a tree fell onto a backyard shed and detached office in the 17900 block of Oak Drive in Redwood Estates.
The Corralitos RAWS reported a gust of 24 mph. A fallen tree damaged the De Un Amor Assisted Living Facility. None of the 19 senior citizen residents were injured and all were later evacuated.
A big rig tipped over on the Eastbound Richmond-San Rafael Bridge carrying Interstate 580, forcing a closure of the bridge.
Glass was blown out of a 52-story building on 555 California in San Francisco, causing the San Francisco Fire Department to issue a shelter-in-place order that continued for four hours. No one was injured in the incident.
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: 1085664, 1085658, 1085659, 1085665, 1085661, 1085662, 1085657, 1085666, 1085815, 1085929, 1085823, 1085824, 1085820, 1085667, 1085478.