A long-period swell from the Central Pacific arrived at the Southern California beaches on February 20th. The swell was strong enough to produce breaking wave heights of 10-12 feet at many of the local beaches.
Every event with a place to put it; 3 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 SGX wrote it up.
A long-period swell from the Central Pacific arrived at the Southern California beaches on February 20th. The swell was strong enough to produce breaking wave heights of 10-12 feet at many of the local beaches. Some localized instances of beach and coastal erosion also occurred.
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 19, 9:32 PM PST, 2 hours 28 minutes earlier.
Area Forecast Discussion
National Weather Service San Diego CA
932 PM PST Mon Feb 19 2024
SYNOPSIS...
Periods of rain and mountain snow are expected through Wednesday.
The heaviest precipitation will fall over Orange County, the San
Bernardino County mountains, and northern San Diego County Tuesday
into Wednesday morning. There is a slight chance of thunderstorms
mainly for the coast and valleys Wednesday morning. Periods of
gusty southwest to west winds are expected late Tuesday into
Wednesday over the mountains locally into the deserts. Dry
conditions expected by late Wednesday afternoon and will continue
into at least Friday. Another Pacific low pressure system will
bring additional chances for precipitation early next week.
&&
.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
.Evening Update...
Scattered showers continue for portions of the central LA Basin this
evening as winds across the mountains continue to weaken.
Current infrared satellite shows an increase in moisture over the
ocean, moving closer to SoCal with our weak atmospheric river.
This will impact our area by the early morning hours, where locally
heavy rain will be possible, mainly northern SD county and points
north and west. The snow level is currently around 7500 feet and
will continue around this level through much of tomorrow before
falling further Tuesday night. Tuesday will have off and on showers
for much of the area, but we will have to see how far south it goes
to impact southern and eastern San Diego County and the Coachella
Valley.
The low will amplify throughout the day on Tuesday before pushing
eastward through Southern California Tuesday night into Wednesday.
This will bring the heaviest rain and mountain snow to much of the
region, where the chance for thunderstorms and gusty winds remain.
Latest HRRR/WRF guidance is in fairly good agreement of these two
moisture surges occurring across our area, with precip ending by
Wednesday morning west of the mountains and the afternoon hours
across the mountains. Dry weather looks to occur Thursday through at
least Saturday.
PREVIOUS DISCUSSION FROM 152 PM Monday...
Scattered, mostly light, showers are expected mid-morning Tuesday
through Tuesday afternoon. High resolution model guidance is
indicating more moderate to heavy rain will develop sometime late
Tuesday afternoon into early Wednesday morning with the passage of
the final trough of this series of systems. This trough passage
is expected to tap into the lingering available moisture in the
atmosphere, bringing more widespread precipitation, that will be
heavy at times. Even with the event basically upon us, there are
still some discrepancies amongst the available guidance, mainly in
regards to the timing and placement of the heaviest
precipitation. Current forecast does have an increase in rainfall
totals for San Diego county for late Tuesday into early Wednesday
morning. Colder air aloft will provide enough instability for at
least a slight chance of thunderstorms, mainly for the coastal
areas and valleys. The trough moves out quickly with precipitation
coming to an end by late Wednesday afternoon.
Rainfall totals for Tuesday morning through Wednesday afternoon are:
1.00-1.75 inches for Orange County and Inland Empire; 0.75-1.30
inches for San Diego county with higher totals in northern San Diego
County; 1-2 inches for the Santa Ana, San Diego, and Riverside
County mountains; 2-4 inches for the San Bernardino County
mountains; 0.30-0.50 inches for the High Desert; 0.10-0.25 inches
for the lower deserts.
Snow levels will be high through Tuesday morning - generally around
8000 ft or higher - falling to around 7000-7500 ft Tuesday
afternoon, and then 6000-6500 ft Wednesday morning. Snow totals for
early Tuesday through Wednesday afternoon are 1-5 inches between
6,000 to 7,000 ft, 5-10 inches from 7,000 to 8,000 feet, and up to 1-
2 feet above 8,000 ft.
Periods of gusty southwest to west winds are expected over the
mountains and locally into the deserts late Tuesday into Wednesday.
Peak wind gusts of 40 to 50 mph are expected. Winds in the deserts
will peak at 30 mph in the High Desert and the San Diego County
deserts.
Zonal flow and weak ridging will bring warmer and drier weather
Thursday and Friday. A touch of offshore flow will help with the
warming on Friday when highs in some of the valleys and inland
Orange County could reach the low 70s. The break in the weather is
short lived, with another closed low forecast to move out of the
Gulf of Alaska towards California on Saturday. While ensemble
guidance is indicating most of the area will get measurable
precipitation, there is still considerable uncertainty surrounding
precipitation amounts and timing. The fastest solutions, though in
the minority, bring precipitation in as early as Saturday evening,
with the slowest holding off until sometime late Sunday or Monday.
The low is currently forecast to dig much further south than this
current system, there is a chance it could be colder with lower snow
levels. In addition to precipitation chances cloudy and windy
conditions with highs several degrees below normal Sunday and Monday
are expected.
&&
.AVIATION...
200530Z...Coast/Valleys/Mountains...Multiple cloud layers with SCT-
BKN 1500-3000 FT MSL, OVC 3500-4500 FT MSL. SCT -SHRA will gradually
become more widespread and heavier after 10Z Tue with widespread
SHRA most of Tue in most locations. VIS will occasionally lower to 1-
3 miles in +SHRA, mainly Tue after 12Z, along with local BKN-OVC 700-
1000 ft MSL. Higher terrain will be obscured.
Deserts...SCT-BKN clouds at/above 15000 ft MSL will prevail through
Tue with areas of BKN clouds 3000-5000 ft MSL and -SHRA mainly after
12Z Tue.
&&
.MARINE...
A Pacific storm will bring a 6-11 foot/14-16 sec swell through
Tuesday. Southerly wind gusts of 20 to 25 knots will be possible for
at least a few hours Tuesday night just ahead of a cold front.
Periods of rain will occur through Wednesday, with the highest
chances Tuesday through early Wednesday morning.
&&
.BEACHES...
The second of the two west swells will continue to build tonight and
peak Tuesday. The swell height will be 6-11 feet with a period
around 15 seconds from near 270 degrees, so local sets to 12 feet
will be likely in San Diego County and 10 feet in Orange County,
with otherwise widespread surf of 5-9 feet. Minor tidal overflow
will likely occur Tuesday during the early morning highs tides of
5.0-5.4 ft. Swell and surf will subside Wednesday.
&&
.SKYWARN...
Skywarn activation is requested.
&&
.SGX WATCHES/WARNINGS/ADVISORIES...
CA...High Surf Advisory until 10 PM PST Tuesday for Orange County
Coastal Areas-San Diego County Coastal Areas.
Flood Watch through Wednesday morning for Orange County Coastal
Areas-Orange County Inland Areas-Riverside County Mountains-
San Bernardino County Mountains-San Bernardino and
Riverside County Valleys-The Inland Empire-San Diego County
Coastal Areas-San Diego County Mountains-San Diego County
Valleys-San Gorgonio Pass Near Banning-Santa Ana Mountains
and Foothills.
Winter Weather Advisory from 1 AM Tuesday to 10 AM PST Wednesday
for Riverside County Mountains-San Bernardino County
Mountains.
PZ...Small Craft Advisory until 10 AM 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.
&&
UPDATE/PUBLIC...APR/CO
AVIATION/MARINE...MaxwellThe national radar mosaic for the moment the first event began.
3 high surf. Local standard time, as filed.
Huntington Beach Lifeguards reported maximum surf heights of up to 12 feet.
Solana Beach Lifeguards reported maximum surf heights of up to 10 feet.
Mission Beach Lifeguards reported maximum surf heights of up to 12 feet.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in California in 2024Every state in 2024This day in weather historyWarnings in California, February 2024
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: 1163100, 1163101, 1163102.