Flash Flood and Blizzard in California, February 21 to 26, 2023

Name: Flash Flood and Blizzard in California, February 21 to 26, 2023
Start: 2023-02-21T16:00
End: 2023-02-26T12:00
Location: California

February 21 to 26, 2023 · NWS SGX · 23 events in 15 counties and zones

An intense period of heavy snow and blizzard conditions, damaging winds, low-elevation snow and widespread flooding rainfall plagued Southern California February 21-27. Very strong, and locally damaging, winds developed in the evening on February 21 and continued through February 22, especially impacting the coast and the mountains.

Where it happened

Every event with a place to put it; 16 filed by county or forecast zone are drawn at its center, in a lighter ring. Tap one for its entry below.

Tornadoes
Tropical storms and surge
Floods
Wind
Hail
Winter weather
Heat and drought
Cold
Fire, smoke and dust
Marine and coastal
Other

Open the live radar over this ground

The toll

Deaths: 0
Injuries: 0
Property damage: $5,000
Crop damage: None recorded
Events: 23

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.

What happened

The episode as NWS SGX wrote it up.

An intense period of heavy snow and blizzard conditions, damaging winds, low-elevation snow and widespread flooding rainfall plagued Southern California February 21-27.

Very strong, and locally damaging, winds developed in the evening on February 21 and continued through February 22, especially impacting the coast and the mountains. Numerous trees were uprooted as a result of the strong winds. Temperatures plummeted on February 22 leading to low-elevation snow and cold-core thunderstorms.

The second, and highly impactful, next wave of the storm system enveloped Southern California starting on February 23. This is the period of heaviest snowfall, and a first-ever Blizzard Warning issued by NWS San Diego was in effect for the San Bernardino County Mountains. Heavy snowfall persisted through early morning on February 26, resulting in FEET of snowfall in the mountains, with many locations in the San Bernardino County Mountains seeing over 50 of snowfall. This resulted in hard closures of many highways in the San Bernardino County Mountains and left people trapped in their homes. Snow levels once again fell on February 25, with snow levels as low as 1000-2000 feet in the Inland Empire and inland Orange County. Widespread heavy thunderstorms occurred leading to local flooding, especially across San Diego County, inland Orange County and portions of the Inland Empire, as well as produced pea size hail.

The impacts of this system, especially in San Bernardino County, would be further exacerbated by an additional significant storm system that would hit only days later, leading to additional FEET of snow.

What forecasters said that day

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 Diego, CA wrote its last area forecast discussion before the first event at Feb 21, 1:54 PM PST, 2 hours 6 minutes earlier.

Area forecast discussion, Feb 21, 1:54 PM PST, 2 hours 6 minutes before

Area Forecast Discussion
National Weather Service San Diego CA
154 PM PST Tue Feb 21 2023

.SYNOPSIS...
West winds will steadily increase through the daytime, becoming
strong and potentially damaging later this evening. Temperatures
and snow levels also take a dive tonight with very low snow levels
anticipated for Wednesday and Thursday. Most of the precipitation
tonight through the weekend will fall as snow in the mountains,
with potential for some light snowfall occurring in portions of
the Inland Empire and the High Deserts as well. Heavier rain and
snowfall looks likely late Thursday through Saturday with the
approach of another upper level low. Precipitation looks to
continue through the weekend across most locations.

&&

.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...

Onshore flow increases through the day today and spreads cooler
air inland. High temperatures today will be a few degrees cooler
than yesterday’s as a result. The onshore flow will become notably
stronger later this afternoon and evening, potentially becoming
damaging in spots in the mountains and desert foothills, as well
as some isolated locations along the coast more susceptible to
wind damage. CANSAC WRF guidance suggests the potential for triple
digit wind gust readings in the mountains and desert foothills
while EFI guidance suggests nearly all ensemble members
forecasting a significant wind event.

Temperatures and snow levels take a significant dive later this
evening. Latest runs of the ECMWF and GFS support 700mb
temperatures falling into the -13 to -15C range, which will favor
snow levels between 1500 and 2500 feet. Precipitation begins later
this evening mainly across areas from the mountains westward.
Overall accumulations this evening and overnight look to be
relatively light, with a brief break in precipitation Wednesday
morning before more substantial precipitation arrives later
Wednesday afternoon and evening. Accumulating snow will be
possible even in some of the valleys down to around 2000-2500 feet
in elevation starting early Wednesday and lasting through
Thursday. Snow will also be possible in portions of the High
Deserts during this time as well, with lower confidence on timing
and amounts in this region.

As implied by the very low snow levels, it will be notably cooler
than seasonal normals through much of the week ahead. Afternoon
high temperatures each day through the weekend will be anywhere
from 10 to 25 degrees cooler than normal, with Wednesday and
Thursday as the coolest days. These days will be characterized by
highs in the lower 50s near the coast, widespread 40s in the
valleys, lower 20s to lower 30s in the mountains, and deserts
ranging from lower 40s to upper 50s. Many daily records for lowest
maximum temperatures on Wednesday and Thursday will be in
jeopardy.

Thursday and Friday will see the approach of another upper level
low, the track of which will remain more offshore compared to this
evening’s upper level system. This next system will also be able
to tap into at least a weak atmospheric river component,
supporting potential for heavier rainfall starting late Thursday
through Saturday. Snow levels will also rise with this system,
topping out around 4000-5000 feet on Friday before falling again
to around 3000 feet this weekend. Total liquid equivalent
precipitation through the weekend will range from around 2 inches
at the coast to upwards of 6 inches in the mountains, with
upslope-favored regions in the San Bernardino Mountains
potentially seeing more than 6 inches. Given the relatively low
snow levels through the duration of this event, many mountain
communities will have the potential to see several feet of
accumulating snow through Sunday.

While the exact end timing of this weekend’s precipitation remains
uncertain, there is a signal for a more prolonged break occurring
on Monday and Tuesday of next week. There remains the potential
for another system arriving during the early to middle portions of
next week, the details of which will be addressed in later
forecast updates.

&&

.AVIATION...
212145Z...SCT-BKN clouds at or above 15000 feet MSL through tonight.
Coastal low clouds will gradually spread inland this afternoon and
evening. Cigs around 1500 feet MSL, rising to 2500-3000 feet after
00Z Wed with tops to 6000 feet. West-facing mountain slopes will
become locally obscured in clouds and fog after 01Z. SHRA (SHSN in
mountains) to develop mountains westward after 01Z.

Very strong westerly winds will develop this evening, peaking
tonight into Wednesday morning. Near coast 25-40 knots and in
mountains 35-50 knots, with local gusts to 80 knots. Strong
up/downdrafts expected around desert mountain slopes, along with
pockets of terrain-induced LLWS and rotors. Areas of BLDU/BLSA
locally reducing vis in deserts.

&&

.MARINE...
Strong gales are expected this evening through Wednesday, peaking
early Wednesday morning. Isolated gusts could reach 50 kt and local
combined seas could reach 20 feet. These winds and seas will
generate particularly hazardous boating conditions. Check the Gale
Warning for more details. Winds weaken and seas subside late
Wednesday night and Thursday, but conditions could be locally
hazardous at times Wednesday night through Saturday.

&&

.BEACHES...
Gales over the coastal waters will generate a large short-period
wind swell tonight through Wednesday. Surf will be 6 to 14 feet,
highest in southern San Diego County. Swimming and surfing will be
dangerous. Coastal flooding is possible, particularly during high
tide Wednesday morning. Check the High Surf Advisory for details.

&&

.HYDROLOGY...
Showers are expected to develop along and west of the mountains
this evening and overnight, with a break then following for much
of the daytime Wednesday for most areas outside of the San Diego
County Mountains. The greater rainfall and liquid equivalent
through Wednesday afternoon is expected in San Diego County
ranging from around 0.10 to 0.25 inch near the coast to one-half
to locally one inch in the mountains. Snow levels near 5500 to
6000 feet this evening will plunge to 1500 to 2500 feet Wednesday.

Periods of more widespread showers are expected for Wednesday
night into the weekend with increasing potential for heavier
precipitation for late Thursday into Saturday. The low snow levels
will gradually rise for Thursday and Friday to around 4000 to
5000 feet for Friday afternoon and evening. A weak atmospheric
river could increase the precipitation potential on Friday, as
suggested by ECMWF/GEFS IVT guidance peaking during the afternoon
and early evening on Friday. Snow levels will lower again for the
weekend to around 3000 feet. Widespread showers will continue into
Saturday and possibly into Sunday as the system moves slowly
eastward.

Storm total rainfall through the coming weekend, could range from
2 inches or more at the coast, to 6 inches or more of liquid
equivalent in the mountains, with 1/2 to 1 inch or more in the
deserts. Runoff should be modest initially, but as the soils
moisten, the arrival of more moderate to heavy rainfall rates
later in the week could lead to greater runoff and flooding
potential. Rising snow levels on Friday afternoon and evening
would suggest that some snow melt could add to the runoff in the
mountains below around 4000 feet.

&&

.SKYWARN...
Skywarn activation is not requested. However weather spotters are
encouraged to report significant weather conditions.

&&

.SGX WATCHES/WARNINGS/ADVISORIES...
CA...High Surf Advisory from 8 PM this evening to 3 AM PST Thursday
     for Orange County Coastal Areas-San Diego County Coastal
     Areas.

     High Wind Warning from 10 PM this evening to 8 PM PST Wednesday
     for San Diego County Coastal Areas.

     Wind Advisory from 10 PM this evening to 6 PM PST Wednesday for
     Orange County Inland Areas-San Bernardino and Riverside
     County Valleys-The Inland Empire-San Diego County Valleys.

     Winter Weather Advisory from 4 AM Wednesday to 10 AM PST
     Thursday for San Bernardino and Riverside County Valleys-
     The Inland Empire-San Diego County Valleys.

     Winter Storm Warning from 6 PM this evening to 3 PM PST Saturday
     for Riverside County Mountains-San Bernardino County
     Mountains-San Diego County Mountains.

     Winter Storm Warning from 6 PM this evening to 6 PM PST Thursday
     for Santa Ana Mountains and Foothills.

     High Wind Warning until 1 PM PST Wednesday for Apple and Lucerne
     Valleys.

     Winter Storm Watch from Thursday morning through late Thursday
     night for Apple and Lucerne Valleys.

     High Wind Warning until 6 PM PST Wednesday for Coachella Valley-
     San Diego County Deserts-San Gorgonio Pass Near Banning.

     Wind Advisory from 10 PM this evening to 8 PM PST Wednesday for
     Orange County Coastal Areas.

PZ...Gale Warning until 10 PM PST Wednesday for Coastal Waters from
     San Mateo Point to the Mexican Border and out to 30 nm-
     Waters from San Mateo Point to the Mexican Border Extending
     30 to 60 nm out including San Clemente Island.

&&

PUBLIC/HYDROLOGY...Adams
AVIATION/MARINE/BEACHES...PG

The radar

The San Diego radar (KNKX), 28 km away, was scanning. The volume nearest the first event began at 15:40 UTC.

Open the radar archive at this moment

Event by event

7 high wind, 6 winter storm, 3 flood, 3 debris flow, 1 winter weather, 1 blizzard, 1 flash flood, 1 strong wind. Local standard time, as filed.

High Wind, San Diego County Mountains

When: February 21, 4:00 PM PST to February 22, 6:00 AM PST
Where: San Diego County Mountains forecast zone
Measured: 73 kt (84 mph) measured gust
Reported by: Mesonet
Coordinates: 33.028, -116.770 (the zone’s center; the record gives no point)

Very strong winds impacted the San Diego County Mountains from the evening on February 21 through the early morning hours on February 22, when widespread wind gusts in excess of 50 mph were observed.

The following are the highest wind gusts recorded across the San Diego County Mountains:|Mesonet station VCMSD Volcan Mountain (SDGE) reported a peak wind gust of 84 mph.|Mesonet station HRPSD Harrison Park (SDGE) reported a peak wind gust of 81 mph.|Mesonet station Boulevard West (SDGE) reported a peak wind gust of 80 mph.|Pine Valley - Horse Launch reported a peak wind gust of 77 mph.|Lucky Five Ranch (SDGE) reported a peak wind gust of 75 mph.|Mesonet station DVI00558 Julian reported a peak wind gust of 70 mph.|Palomar Mountain Lookout reported a peak wind gust of 70 mph.

High Wind, San Bernardino County Mountains

When: February 21, 4:00 PM PST to February 22, 12:00 AM PST
Where: San Bernardino County Mountains forecast zone
Measured: 82 kt (94 mph) measured gust
Reported by: Mesonet
Coordinates: 34.841, -116.178 (the zone’s center; the record gives no point)

Very strong winds impacted the San Bernardino County Mountains through the afternoon and evening on February 21, when widespread wind gusts in excess of 50 mph were observed.

The following are the strongest wind gusts reported across the San Bernardino County Mountains:|Burns Canyon reported a peak wind gust of 94 mph.|Mesonet station SE269 Cushenbury Springs reported a peak wind gust of 92 mph.|Mesonet station 424SE Silverwood Lake reported a peak wind gust of 71 mph.|Mesonet station SCE338 Cajon Lookout reported a peak wind gust of 68 mph.|Mesonet station SCE364 Lake Arrowhead reported a peak wind gust of 61 mph.

High Wind, San Gorgonio Pass Near Banning

When: February 21, 6:00 PM PST to February 22, 3:00 AM PST
Where: San Gorgonio Pass Near Banning forecast zone
Measured: 69 kt (79 mph) measured gust
Reported by: RAWS
Coordinates: 33.744, -115.994 (the zone’s center; the record gives no point)

Very strong winds impacted the San Gorgonio Pass from the evening on February 21 through the early morning hours on February 22, when widespread wind gusts in excess of 50 mph were observed.

The following are the strongest wind gusts reported:|Whitewater RAWS reported a peak wind gust of 79 mph.|Mesonet station 015SCE Whitewater reported a peak wind gust of 73 mph.|Mesonet station 289SCE Whitewater reported a peak wind gust of 69 mph.|Mesonet station SCE1010 Cabazon reported a peak wind gust of 68 mph.|Mesonet station Whiteater Canyon SCE581 reported a peak wind gust of 65 mph.|Mesonet station Desert Hot Springs reported a peak wind gust of 63 mph.

High Wind, Orange County Coastal

When: February 21, 10:00 PM PST to February 22, 5:00 AM PST
Where: Orange County Coastal forecast zone
Measured: 56 kt (64 mph) measured gust
Reported by: Mesonet
Coordinates: 33.677, -117.776 (the zone’s center; the record gives no point)

Anomalously strong winds impacted the Orange County coastline from the late evening hours on February 21 through the early morning on February 22.The following are the strongest wind reports from the coast:

Mesonet station SE024 Laguna Beach reported a peak wind gust of 65 mph.|San Clemente 3 reported a peak wind gust of 59 mph.|Huntington Beach Pier reported a peak wind gust of 57 mph.|Newport Pier reported a peak wind gust of 57 mph.|Huntington Beach reported a peak wind gust of 50 mph.

A trained spotter reported tree damage as well as shingles blown off of a structure.

High Wind, Coachella Valley

When: February 21, 10:00 PM PST to February 22, 3:00 AM PST
Where: Coachella Valley forecast zone
Measured: 43 kt (49 mph) measured gust
Property damage: $5,000
Reported by: ASOS
Coordinates: 33.744, -115.994 (the zone’s center; the record gives no point)

Strong winds impacted the Coachella Valley from late in the evening on February 21 through the early morning hours on February 22, when widespread wind gusts of 40-55 mph were reported.

The following are the strongest wind gusts reported across the Coachella Valley:|Thermal Airport reported a peak wind gust of 56 mph.|Mesonet station SCE412 Palm Canyon reported a peak wind gust of 52 mph.|La Quinta reported a peak wind gust of 51 mph.|Mesonet station SCE416 reported a peak wind gust of 50 mph.

Wind damage was reported near Palm Springs, where a large tree fell onto the hood of a car.

High Wind, San Diego County Coastal Areas

When: February 22, 12:00 AM PST to 12:00 PM PST
Where: San Diego County Coastal Areas forecast zone
Measured: 51 kt (59 mph) measured gust
Reported by: Mesonet
Coordinates: 33.028, -116.770 (the zone’s center; the record gives no point)

Anomalously strong winds impacted the San Diego County coastline from the very early morning hours on February 22 through the afternoon, peaking during the overnight hours through sunrise.

The following are the strongest wind reports from the coast:|Mesonet station XZUN Silver Strand Beach reported a peak wind gust of 58 mph.|Mesonet station XOCJ Oceanside Jetty reported a peak wind gust of 57 mph.|AWOS Station KNXF Red Beach Airport reported a peak wind gust of 56 mph.

Tree damage was also reported during the early morning hours, with a toppled tree resulting in car damage in Mission Valley; a large Torrey Pine tree fell on a home in Del Mar Heights with a branch crashing through the roof in the living room; and a large Torrey Pine tree toppled over at the Torrey Pines Golf Course.

Winter Storm, San Diego County Mountains

When: February 22, 12:00 AM PST to February 26, 12:00 PM PST
Where: San Diego County Mountains forecast zone
Reported by: Trained Spotter
Coordinates: 33.028, -116.770 (the zone’s center; the record gives no point)

An extensive period of heavy snow impacted the San Diego County Mountains February 22-26. Chain controls were activated as early as the morning on February 22 ahead of the heavy snow. The following are some of the heaviest storm total snow reports from the San Diego County Mountains:

Palomar Mountain COOP (5600'): 36|Birch Hill Palomar Mountain (5700'): 32|Palomar Mountain (CalFire): 28|Julian North Peak (5100'): 25|Mt Laguna (6100'): 24.

Winter Weather, Riverside County Mountains

When: February 22, 12:00 AM PST to February 26, 4:00 AM PST
Where: Riverside County Mountains forecast zone
Reported by: Trained Spotter
Coordinates: 33.744, -115.994 (the zone’s center; the record gives no point)

An extensive period of heavy snow impacted the Riverside County Mountains February 22-26. The following are some of the heaviest storm total snow reports from the Riverside County Mountains:

Long Valley Ranger Station (8400'): 60|Idyllwild COOP (5400'): 36|Idyllwild (5600'): 17.

Winter Storm, San Bernardino and Riverside County Valleys - the Inland Empire

When: February 23, 12:00 AM PST to February 25, 11:59 PM PST
Where: San Bernardino and Riverside County Valleys - the Inland Empire forecast zone
Reported by: Department of Highways
Coordinates: 34.293, -116.086 (the zone’s center; the record gives no point)

Snow levels falling to between 1000-2000 feet on February 23rd and 25th allowed for accumulating snow at various locations in the Inland Empire. Most accumulations were around 1 inch or less, but were still enough to cause hazardous travel conditions. Accumulating snow was observed near Fontana and Devore, with rain and snow mixing in near Riverside, Moreno Valley, and Temecula. Total snowfall of 10.5 inches was observed near Devore, just below the Cajon Pass which led to the closing of the I-15 and I-215 interchange due to multiple disabled vehicles. A severe pile-up involving 20 vehicles occurred around 11 PM on February 22 in Yucaipa; officials said the crash was caused by winter conditions, including icy slush that was seen on the road.

Blizzard, San Bernardino County Mountains

When: February 23, 12:00 AM PST to February 26, 12:00 PM PST
Where: San Bernardino County Mountains forecast zone
Reported by: County Official
Coordinates: 34.841, -116.178 (the zone’s center; the record gives no point)

A historic blizzard impacted the San Bernardino County Mountains February 23-26, prompting the first-ever Blizzard Warning issued by NWS San Diego. The heaviest snowfall occurred on February 24-25. Snow accumulations on the order of FEET inundated mountain communities with 70-90+ inches recorded at ski resorts, and 2-3 feet occurred at mountain communities located at 5000-7000 feet.

This snowfall severely incapacitated communities, resulting in hard closures of Highway 2, Highway 18, Highway 138 and Highway 330 from Friday, February 24 through Monday, February 27. Prior to the road closures, multiple vehicles had been stuck or disabled. Vehicles also became stuck on the heavily traveled I-15 through the Cajon Pass Saturday morning, which ended up being shut down due to snow and ice early Saturday afternoon. As of the evening on February 27, these highways partially reopened to escort residents back up the mountain and allow for food and fuel delivery to mountain communities. 500 6th and 7th grade students who were attending a Science Camp in the mountains were unable to return home as scheduled on Feb 24th.

The following are some of the highest recorded snow totals from this region:

Impacts extended well beyond the end time of this round of snow, especially as another storm system produced additional FEET of snowfall in the following days. Residents remained trapped, transportation remained halted and resources ran dry.

Flood, San Diego

When: February 23, 7:43 AM PST
Where: San Diego County, San Marcos to 1.8 mi N of Lake San Marcos
Cause: Heavy Rain
Reported by: Public
Coordinates: 33.150, -117.170

Public report of flooding at Country Club Dip south of Harmony Grove Road, resulting in its closure.

Debris Flow, San Bernardino

When: February 24, 1:20 PM PST
Where: San Bernardino County, 5 mi NNW of Fontana to 4.35 mi NE of Etiwanda
Cause: Heavy Rain
Reported by: Department of Highways
Coordinates: 34.167, -117.463

The Department of Highways reported flooding and mud along the Duncan Canyon Road offramp, with two vehicles stopped and on vehicle in two feet of mud.

Debris Flow, San Bernardino

When: February 24, 8:30 PM PST
Where: San Bernardino County, 5 mi NNE of Devore to 2.83 mi WSW of Cedarpines Park
Cause: Heavy Rain
Reported by: Department of Highways
Coordinates: 34.287, -117.367

The Department of Highways reported a vehicle stuck in mud on Cleghorn Road off of SR-1138. Search and rescue in place at midnight.

Flash Flood, San Bernardino

When: February 24, 8:45 PM PST
Where: San Bernardino County, 2 mi ESE of Lytle Creek to 2.68 mi E of Lytle Creek
Cause: Heavy Rain
Reported by: Fire Department/Rescue
Coordinates: 34.209, -117.498

San Bernardino County Fire conducted a swift water rescue of one occupant from a truck. Report of rushing water enveloping the lower half of the truck.

High Wind, San Bernardino and Riverside County Valleys - the Inland Empire

When: February 24, 10:00 PM PST to February 25, 5:00 AM PST
Where: San Bernardino and Riverside County Valleys - the Inland Empire forecast zone
Measured: 51 kt (59 mph) measured gust
Reported by: Mesonet
Coordinates: 34.293, -116.086 (the zone’s center; the record gives no point)

Strong winds impacted western and southern portions of the Inland Empire late evening on February 24 through the early morning hours on February 25 ahead of a cold front. The following are the strongest wind reports:

Mesonet station Corona RAWS reported a peak wind gust of 63 mph.|Temescal Valley reported a peak wind gust of 59 mph.|Temecula reported wind gusts of 40 to 55 mph.

The Department of Highways reported a downed tree blocking te right land of Campbell Ranch Road at Mayhew Canyon Road in Temescal.

Winter Storm, Santa Ana Mountains and Foothills

When: February 25, 12:00 AM PST to 11:59 PM PST
Where: Santa Ana Mountains and Foothills forecast zone
Reported by: Trained Spotter
Coordinates: 33.483, -116.847 (the zone’s center; the record gives no point)

Snow levels fell to between 1500-2000 feet in the Santa Ana Mountains on the morning of February 25th. Per a report from a trained spotter, rain changed over to snow in Silverado Canyon at elevations around 1800 feet.

Winter Storm, Apple and Lucerne Valleys

When: February 25, 12:00 AM PST to 11:59 PM PST
Where: Apple and Lucerne Valleys forecast zone
Reported by: Trained Spotter
Coordinates: 34.841, -116.178 (the zone’s center; the record gives no point)

Snow levels fell to between 2000-3000 feet in the Apple and Lucerne Valleys on the morning of February 25th. Spotters reported upwards of 6 to 12 inches of accumulating snow near Phelan. Per reports from San Bernardino County Public Works, roughly 1-5 of snow fell in locations including Victorville, Apple Valley, and lower elevations near Hesperia.

Winter Storm, Riverside County Mountains

When: February 25, 12:00 AM PST to 11:59 PM PST
Where: Riverside County Mountains forecast zone
Reported by: Trained Spotter
Coordinates: 33.744, -115.994 (the zone’s center; the record gives no point)

Snow levels fell to between 3000-3500 feet in the Riverside County Mountains on February 25th. Areas along the San Diego-Riverside County border near Aguanga received roughly 3 to 6 inches of accumulating snowfall.

Winter Storm, San Diego County Mountains

When: February 25, 12:00 AM PST to 11:59 PM PST
Where: San Diego County Mountains forecast zone
Reported by: Trained Spotter
Coordinates: 33.028, -116.770 (the zone’s center; the record gives no point)

Snow levels fell to between 2700-3500 feet in the San Diego County Mountains on February 25th. Areas along the San Diego-Riverside County border near Aguanga received roughly 3 to 6 inches of accumulating snowfall, with up to 2 inches of snow reported as low as 2700 feet in Oak Grove. Areas near Santa Ysabel at elevations around 3000 feet received 3 inches of accumulating snowfall.

Strong Wind, Orange County Inland

When: February 25, 12:24 AM PST
Where: Orange County Inland forecast zone
Measured: 37 kt (43 mph) measured gust
Reported by: Department of Highways
Coordinates: 33.677, -117.776 (the zone’s center; the record gives no point)

The Department of Highways reported a downed tree blocking the slow lanes of Highway 55 north of the Highway 73 transition.

Flood, Orange

When: February 25, 3:00 AM PST to 5:00 AM PST
Where: Orange County, 3 mi S of Santa Ana to 2 mi NE of (Sna)santa Ana Co Ar
Cause: Heavy Rain
Reported by: Department of Highways
Coordinates: 33.707, -117.880

Heavy rain led to flooding early in the morning on February 25 across inland Orange County, centered around the community of Costa Mesa. The Department of Highways reported flooding at the Bristol Street on-ramp on I-405 with vehicles stuck in the floodwaters; street flooding leading to road closures and stranded vehicles; and SR-173 and Campus Drive had 1-2 feet of water in two lanes.

Debris Flow, Riverside

When: February 25, 3:20 AM PST
Where: Riverside County, 4 mi WSW of Murrieta to 3.51 mi WSW of Murrieta
Cause: Heavy Rain
Reported by: Department of Highways
Coordinates: 33.528, -117.284

Department of Highways reported a 3-4 foot boulder came off the mountain and fell into the road following heavy rainfall.

Flood, San Diego

When: February 25, 7:06 AM PST
Where: San Diego County, 2 mi E of Vista to 2.62 mi ESE of Vista
Cause: Heavy Rain
Reported by: Department of Highways
Coordinates: 33.220, -117.215

CalTrans report of flooding across both lanes of Foothill Drive due to heavy rain.

What these are

High Wind: Sustained non-thunderstorm winds of 40 mph or more for an hour, or gusts of 58 mph or more.
Winter Storm: A storm that brought snow, sleet or freezing rain at warning levels, usually over several hours or days.
Winter Weather: Snow, sleet or freezing rain below warning levels that still caused disruption, damage or casualties.
Blizzard: Sustained winds or frequent gusts of 35 mph or more with falling or blowing snow that cuts visibility below a quarter mile for three hours or longer.
Flood: Flooding that develops more slowly than a flash flood: rivers leaving their banks, or water standing over land for an extended time.
Debris Flow: A fast-moving slurry of mud, rock and debris, usually on a slope soaked by heavy rain or stripped by a fire.
Flash Flood: Flooding that begins within six hours of the rain that causes it, or of a dam or levee failure or ice jam release, often with deadly speed.
Strong Wind: Non-thunderstorm winds below high wind criteria that nonetheless caused damage or casualties.

After NWS Directive 10-1605, the rules offices file Storm Data by.

The same day elsewhere

Every storm in California in 2023 Every state in 2023 This day in weather history Warnings in California, February 2023

Sources

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: 1078907, 1078911, 1078917, 1078920, 1078923, 1078896, 1080317, 1080318, 1079833, 1080178, 1079840, 1079858, 1079860, 1079838, 1079845, 1079834, 1079835, 1079836, 1079837, 1079847, 1079848, 1079842, 1079839.