Another strong winter storm impacted Southwestern California. The storm brought winter storm conditions the local mountains with snowfall totals of 2 to 4 feet and southerly winds gusting in excess of 80 MPH.
Every event with a place to put it; 9 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 LOX wrote it up.
Another strong winter storm impacted Southwestern California. The storm brought winter storm conditions the local mountains with snowfall totals of 2 to 4 feet and southerly winds gusting in excess of 80 MPH. Other areas also experienced some strong winds. Additionally, scattered thunderstorms developed across the area, spawning two weak tornadoes.
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 Los Angeles, CA wrote its last area forecast discussion before the first event at Mar 21, 12:02 PM UTC, 1 hour 38 minutes earlier.
Area Forecast Discussion...UPDATED
National Weather Service Los Angeles/Oxnard CA
502 AM PDT Tue Mar 21 2023
.SYNOPSIS...20/716 PM.
Moderate to heavy rain and mountain snow will spread in through
early Tuesday morning as a strong storm moves over the region
through Wednesday. Strong and potentially damaging winds will
move into the area through Wednesday. Generally dry and cool
conditions are then expected Thursday through Sunday.
&&
.SHORT TERM (TDY-THU)...21/318 AM.
Today's storm has enveloped the area with light rain and mtn snow
falling over the entire area. The cold (533 dam) upper low
responsible for the weather is to the west of the Bay Area. The
low will swing a cold front up from the SW to the NE around dawn
which will produce a period of mdt to hvy rain and strong winds.
After the front moves through the low will feed in a near
continuous stream of showers to the area. There is a slight chc
of TSTMs this afternoon across SLO and western SBA counties due
the destabilizing effects of the cold upper low (-28 C at 500 mb).
This cold air will move south in the evening bringing a slight
chc of TSTMs to the entire area. The upper low will be very slow
to move and wrap around shower activity will likely continue into
Wednesday evening or even Thursday morning.
Rainfall totals still call for 1-3 inches across the csts/vlys
with 3-6 inches across the foothills and mountains through
Wednesday night. Rainfall rates will generally range between
0.25-0.50 inches/hour, but local rates of 0.50-1.00 inches/hour
will be possible this morning with the front and associated with
any thunderstorm activity. A flood watch is in effect for the area
due to the very wet antecedent conditions and expected rainfall.
Snow levels will be a little tricky as the south flow will rise
snow levels across the coastal side but will not affect the
interior too much. Snow levels will then fall after the winds
subside and the colder air moves in. in general snow levels will
start near 5500 feet and will fall to the 3000-4500 foot tonight.
Snowfall totals will likely be impressive at the higher elevations
with several feet of snow expected above 6000 feet with from 2-10
inches in the 3500-5000 foot range. Winter storm warnings are in
effect for the SBA/VTA/LA mountains due the combination of heavy
snow and strong winds (70 to 80 mph gusts). Snow levels will fall
overnight and several inches of snow is possible across mountain
roadways, including the I-5 through the Grapevine.
Since the low is much closer to the area than usual the pressure
gradient is stronger. This will generate stronger than usual
winds and gusts across the entire area. The strongest winds away
from the mtns will occur across the interior valleys of San Luis
Obispo and Santa Barbara counties and the Antelope Valley (gusts
60-75 MPH). High wind warnings are in effect for these area. Wind
advisories for gusts 40 to 50 mph are in effect for the rest of
the area.
Max temps today will be in the lower 60s and will fall into the
50s for Wednesday. Wednesdays max temps will be 10 to 15 degrees
blo normal.
There may be a few lingering showers on Thursday morning depending
on the speed of the upper low's departure. Otherwise look for
decreasing clouds and a 3 to 5 degree warming trend.
.LONG TERM (FRI-MON)...21/332 AM.
Not much to talk about in the xtnd as the region will get a break
form the train of storms. Both the GFS and EC deterministic and
their respective ensembles (GEFS and EPS) agree that there will be
dry NW slightly cyclonic flow through at least Sunday.
Skies through Sunday will be partly cloudy at worst. Max temps
will hover in the upper 50s to mid 60s or 8 to 12 degrees blo
normals. Overnight lows will also not fell very spring like and
will fall into the upper 30s to mid 40s for most areas.
There is a chc of a system arriving on Monday, but there is little
in the way of mdl consensus about it. Right now it looks like
Monday will be dry but cloudier with any storminess holding off
until Tuesday.
&&
.AVIATION...21/1159Z.
At 12Z at KLAX, there was a 5500 feet deep moist layer and no
inversion.
Low confidence in the current forecast for all sites through the
period. Cig and Vis will vary frequently between MVFR and IFR
conds. Rain intensity will also change frequently with periods
rain likely through 22/12Z (and beyond). Good confidence that
winds will be stronger than normal but lower confidence on timing
and direction. 15-20% chance of TSRA at KPRB, KSBP, KSMX, and KSBA
18Z Tue-06Z Wed and at all other TAF sites 00Z-12Z Wed.
KLAX...Low confidence in TAF. Cigs and Vis will vary frequently.
MVFR conds will occur the most but low VFR and LIFR conds are
possible at times. Rain intensity will vary frequently as well.
Good confidence in a greater than 10 kt east wind component
through 17Z Tue, with a 30 percent chc of it lasting to 21Z Tue.
KBUR...Low confidence in TAF. Cigs and Vis will vary frequently.
MVFR conds will occur the most but low VFR and LIFR conds are
possible at times. Rain intensity will vary frequently as well.
&&
.MARINE...21/248 AM.
A potentially dangerous storm will sweep across the coastal
waters today into Wednesday.
This morning, strong southeast GALE FORCE winds associated with a
deepening surface low will sweep quickly across the coastal
waters from west to east and encompass all sections of the coastal
waters. Isolated storm force gusts to 50 knots will be possible
across zones 670/673. A potentially strong cold front associated
with the low pressure system will bring possible thunderstorms
and switch the winds to southwest by afternoon.
The southwest winds will eventually drop to SCA speeds tonight
and continue into Wednesday, shifting northwesterly on Wednesday.
There is a 40% chance that winds fall below Gale Force by
Wednesday morning, resulting in the Warning being downgraded to a
SCA early.
With the storm, seas will rise to SCA levels for all the waters
and continue through at least late Thursday. However, Friday
night winds and seas will likely rise once again to SCA levels.
&&
.BEACHES...21/252 AM.
A powerful storm will move into the coastal waters today into
Wednesday, resulting in high surf and strong rip currents from
late tonight into Thursday morning. Surf will range from 5-10
feet south of Point Conception, and 8-13 feet along the Central
Coast. Surf will be highest across west and southwest- facing
beaches.
The combination of high surf and above normal tides will bring
the risk of minor coastal flooding to low-lying beach locations
this morning into Wednesday night. There is also the potential
for localized minor coastal flooding this morning through
Wednesday evening across the San Luis Obispo Coast (especially
near Pismo Beach and Oceano), and Wednesday morning through
Thursday evening for the Ventura County beaches as a fetch of
southwest onshore winds will couple with increasing surf and high
tides.
There is a chance of another round of high surf over the weekend
for the Central Coast Beaches.
&&
.LOX WATCHES/WARNINGS/ADVISORIES...
CA...Flood Watch in effect through Wednesday afternoon for zones
38-88-340>352-354>358-362-366>376-378>380. (See LAXFFALOX).
High Wind Warning in effect until 11 PM PDT this evening for
zones 38-343>345-381>383. (See LAXNPWLOX).
Wind Advisory in effect until 11 PM PDT this evening for
zones 87-88-340>342-346>352-354>358-362-366>375-548>550. (See LAXNPWLOX).
Coastal Flood Advisory in effect until 11 PM PDT Wednesday
for zones 340-346. (See LAXCFWLOX).
High Surf Advisory in effect from 9 PM this evening to 2 AM
PDT Thursday for zones 340-346. (See LAXCFWLOX).
High Surf Advisory in effect from 2 AM Wednesday to 2 AM PDT
Thursday for zones 349-350. (See LAXCFWLOX).
Winter Storm Warning in effect until 11 PM PDT Wednesday for
zones 353-376>380. (See LAXWSWLOX).
High Surf Advisory in effect from 2 AM Wednesday to 3 PM PDT
Thursday for zone 354. (See LAXCFWLOX).
Coastal Flood Advisory in effect from 5 AM Wednesday to 11 PM
PDT Thursday for zone 354. (See LAXCFWLOX).
High Surf Advisory in effect from 2 AM Wednesday to 5 AM PDT
Thursday for zones 362-366. (See LAXCFWLOX).
PZ...Gale Warning in effect until 9 AM PDT Wednesday for zones
645-650-655-670-673-676. (See LAXMWWLOX).
&&
PUBLIC...Rorke
AVIATION...Lund
MARINE...Gomberg/Lund
BEACHES...Gomberg/Lund
SYNOPSIS...Hall
weather.gov/losangeles
Experimental Graphical Hazardous Weather Outlook at:
https://www.weather.gov/erh/ghwo?wfo=loxThe Vandenberg AFB radar (KVBX), 61 km away, was scanning. The volume nearest the first event began at 00:43 UTC.
6 winter storm, 3 high wind, 2 tornado. Local standard time, as filed.
Strong southerly winds impacted the mountains of San Luis Obispo county. Some peak wind gusts from the local mesonet include: Mount Lowe (gust 66 MPH) and Friis Camp (gust 59 MPH).
Strong southerly winds impacted the Santa Lucia Mountains in San Luis Obispo county. Some peak wind gusts from the local mesonet include: TV Towers (gust 64 MPH), High School Hill (gust 61 MPH) and Camino Del Capitan (gust 58 MPH).
Winter storm conditions developed across the interior mountains of Santa Barbara county. Snowfall totals of 1 to 2 feet were reported above 5500 feet. Additionally, there were some very strong southerly winds with the Tepusquet RAWS reporting gusts up to 59 MPH.
Strong southerly winds impacted the interior valleys of San Luis Obispo county. Some peak wind gusts from the local mesonet include: Navajo Flats (gust 59 MPH) and Lewis Ranch Road (gust 58 MPH).
Winter storm conditions developed across the western range of the San Gabriel Mountains. Snowfall totals of 2 to 4 feet were reported above 6000 feet elevation with 10 to 20 inches between 5000 and 6000 feet. Additionally, there were some very strong southerly winds. Some peak gusts from the local mesonet include: Magic Mountain Truck Trail (gust 102 MPH), Mill Creek RAWS (gust 76 MPH) and Camp Nine (gust 75 MPH).
Winter storm conditions developed across the western range of the San Gabriel Mountains. Snowfall totals of 2 to 4 feet were reported above 6000 feet elevation with 10 to 20 inches between 5000 and 6000 feet. Additionally, there were some very strong southerly winds. Some peak gusts from the local mesonet include: Ford Observatory (gust 76 MPH), Yucca Circle (gust 65 MPH) and Clear Creek RAWS (gust 60 MPH).
Winter storm conditions developed across the Interstate 5 Corridor in the Los Angeles county mountains. Snowfall totals of 1 to 3 feet were reported above 6000 feet elevation with 10 to 20 inches between 5000 and 6000 feet. Additionally, there were some very strong southerly winds. Some peak gusts from the local mesonet include: Whitaker Peak (gust 54 MPH) and Sandberg ASOS (gust 53 MPH).
Winter storm conditions developed across the southern Ventura county mountains. Snowfall totals of 1 to 3 feet were reported above 6000 feet elevation with 8 to 16 inches between 5000 and 6000 feet. Additionally, there were some very strong southerly winds. The sensor at Sycamore Canyon reported wind gusts up to 79 MPH.
Winter storm conditions developed across the northern Ventura county mountains. Snowfall totals of 1 to 3 feet were reported above 6000 feet elevation with 8 to 16 inches between 5000 and 6000 feet. Additionally, there were some very strong southerly winds with gusts in excess of 50 MPH reported.
A weak tornado developed in the community of Carpinteria. The EF0 tornado impacted the area near the intersection of Highway 192 and Cravens Lane. In a mobile home park, 26 homes were damaged. Also, several powerlines were blown down. One injury was reported.
A weak tornado developed in the community of Montebello. The EF1 tornado impacted the area around the intersection of Washington Boulevard and Maple Avenue. There was substantial damage to the industrial warehouse and commercial business district, including nearly total roof collapse in one building and a total of 17 damaged structures. Numerous vehicles were damaged due to flying debris.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in California in 2023Every state in 2023This day in weather historyThe tornado archive for California, 2023Warnings 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: 1091225, 1091227, 1091221, 1091224, 1091210, 1091211, 1091213, 1091219, 1091220, 1091239, 1091231.