Surface high pressure over the Great Basin brought gusty cold Santa Ana winds to Southern California. Gusty winds occurred mainly on the 3rd and 4th, with peak gusts around 70-75 mph in the wind prone locations (passes, mountains, canyons).
Every event with a place to put it; 10 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.
Surface high pressure over the Great Basin brought gusty cold Santa Ana winds to Southern California. Gusty winds occurred mainly on the 3rd and 4th, with peak gusts around 70-75 mph in the wind prone locations (passes, mountains, canyons). The dry air mass brought extreme radiational cooling to the valleys and High Desert each night. Temperatures dipped down into the mid 30s along the coast, the mid 20s to mid 30s for the valleys, and into the teens and low 20s in the High Desert.
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 2, 9:12 PM PST, 48 minutes earlier.
Area Forecast Discussion
National Weather Service San Diego CA
912 PM PST Sun Feb 2 2020
.SYNOPSIS...
A cold front will move through Southern California tonight, bringing
strong gusty west winds, light precipitation, and cooler weather.
Dry weather and gusty offshore flow returns on Monday through
Wednesday with a lingering chill. Freezing temperatures are possible
both Tuesday and Wednesday mornings in wind-sheltered areas in the
valleys. Warmer weather returns for the latter half of the week.
&&
.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
Low clouds were surging inland across the valleys this evening and
some patchy drizzle has been reported. The 00Z Miramar sounding
indicated the sfc-based inversion of this morning had lifted and was
based around 1500 FT. Other than the moisture in the shallow marine
layer, the profile was dry. A big increase in winds aloft was noted
over the past 24 hours with a peak of 45 KTS near 20K FT. The sfc
pressure gradient from KSAN to SW NV reached 14.6 MBS at 00Z and has
weakened since. The 18Z WRFEMS shows winds peaking over the
mts/deserts through about midnight before slowly decreasing. The 18Z
run is not as strong as previous runs and so far no high winds have
been reported. Peak wind gusts through 8 PM PDT have been posted and
headlined on our web page.
Expect more scattered, light showers to develop this evening, ending
late tonight. No forecast changes this evening with winds still
expected to peak later tonight in the mts/deserts.
From previous discussion...
As of 1 PM, current satellite imagery shows low clouds becoming more
widespread along the coast. Clouds will continue to move inland as
the front approaches this afternoon and evening. The incoming front
will bring light precipitation over and west of the mountains as
well as gusty west winds to the mountains, deserts, and coastal
waters. Over land, gusts up to 65 mph are possible, with the
strongest winds expected near the desert foothills and through the
San Gorgonio Pass. A High Wind Warning remains in effect through
Monday morning. A Gale Warning remains in effect for the coastal
waters, please see the marine discussion for more information.
Precipitation totals for this storm are expected to be fairly light.
A few hundredths to locally a tenth of an inch of rain is expected
west of the mountains. Orographics will pay a role on the coastal
slopes of mainly the Riverside and San Diego County mountains. On
those slopes, local rain totals could be around a quarter of an
inch. Less than an inch of snow is expected in the mountains, except
the Santa Ana mountains where no snow is expected. A cold air mass
will be left behind after the front passes. High temperatures on
Monday will be well below average and up to 25 degrees cooler than
highs on Saturday. Low temperatures on Tuesday and Wednesday will
reach near or below freezing in wind sheltered locations in the
valleys and could drop to below 20 degrees in portions of the High
Desert. A Freeze Watch has been issued for the San Diego County
Valleys, Inland Empire, and Low Deserts and a Hard Freeze Watch has
been issued for the High Desert for Tuesday and Wednesday mornings.
Winds will quickly turn offshore Monday morning, increasing in
strength through the day. Winds will mostly be coming out of the
north to northeast, keeping the windiest locations to the coastal
slopes and foothills of the San Bernardino and Santa Ana mountains.
Gusty winds have the potential to reach portions of the Inland
Empire and inland Orange County. Current guidance shows winds
weakening and turning slightly onshore Wednesday evening.
The latter half of the week will see warmer weather, relative the
the beginning of the week, the possible return of low clouds, and
lighter winds. Global ensembles are continuing to show another cold
low pressure system making its way into Southern California February
9-10. While it is still early and guidance could change
significantly, it looks like this system has the potential to bring
rain and mountain snow to the area.
&&
.AVIATION...
030445Z...Low clouds with bases near 1500 ft MSL along and west of
the mountains this evening. Bases will lift to around 2500 ft
overnight with gradual clearing from northwest to southeast after
09Z as a cold front passes. ISO -SHRA with 6 SM vis possible through
about 11Z along with coastal slope obscurations. After 16Z Monday,
SCT high clouds AOA 20000 ft MSL and unrestricted vis.
West to Southwest winds strengthening overnight with sfc gusts 40-50
kt along the mountain ridges, desert mountain slopes, and locally
into the deserts through Sunday night. STG-SVR UDDFS likely over and
east of the mountains, with areas of LLWS and rotors in the deserts,
including near KPSP. Winds will then switch northeasterly with gusts
of 25-35 kt along below the Cajon pass into portions of the Inland
Empire, Santa Ana Mountains, and inland Orange County. Northeast
winds will strengthen further Monday evening with LLWS and STG UDDFS
possible over and SW of the mountains.
&&
.MARINE...
Northwest winds will strengthen tonight, peaking with sustained
winds of 20 to 30 kts and gusts to 35 kts. Strongest winds will be
in the outer coastal waters. Winds will weaken Monday morning with
local gusts 25 to 30 kts possible throughout the day.
The strong NW winds will result in very high seas this evening into
Monday. Seas of 11 and 15 feet in the inner waters and 15 and 17
feet in the outer waters are possible, with a period of 12 seconds.
A Gale Warning remains in effect through noon Monday. The strong
winds and high seas with generate very hazardous boating conditions,
capable of damaging and capsizing vessels.
&&
.BEACHES...
A Beach Hazards Statement remains in effect until 5 AM Tuesday for
elevated surf of 4-6 ft with local sets to 7 ft and strong rip
currents. Highest sets are expected in southern San Diego County.
Though waves are not expected to be significantly large, the amount
of water moving in due to strong winds and associated swell may
result in flooding of low-lying beach areas and parking lots, along
with minor beach erosion.
&&
.SKYWARN...
Skywarn activation is not requested. However weather spotters are
encouraged to report significant weather conditions.
&&
.SGX WATCHES/WARNINGS/ADVISORIES...
CA...High Wind Warning until noon PST Monday for Apple and Lucerne
Valleys-Coachella Valley-Riverside County Mountains-San
Bernardino County Mountains-San Diego County Deserts-San
Diego County Mountains-San Gorgonio Pass Near Banning.
Freeze Watch from Monday evening through Tuesday morning for
Coachella Valley-San Bernardino and Riverside County
Valleys-The Inland Empire-San Diego County Deserts-San
Diego County Valleys.
Freeze Watch from Tuesday evening through Wednesday morning for
Coachella Valley-San Bernardino and Riverside County
Valleys-The Inland Empire-San Diego County Deserts-San
Diego County Valleys.
Hard Freeze Watch from Monday evening through Tuesday morning
for Apple and Lucerne Valleys.
Hard Freeze Watch from Tuesday evening through Wednesday morning
for Apple and Lucerne Valleys.
Beach Hazards Statement through late Monday night for Orange
County Coastal Areas-San Diego County Coastal Areas.
PZ...Gale Warning until noon PST Monday 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...10/CO/Maxwell
AVIATION/MARINE/BEACHES...SSThe national radar mosaic for the moment the first event began.
7 high wind, 3 frost/freeze. Local standard time, as filed.
Whitewater RAWS reported a peak wind gust of 62 knots between 2200 and 2300 PST on February 2nd.
Volcan mountain reported a peak wind gust of 63 knots between 0000 and 0100 PST on February 3rd.
Harrison Park reported a peak wind gust of 63 knots between 0000 and 0100 PST on February 3rd.
CSU San Bernardino reported a peak wind gust of 64 knots between 0500 and 0600 PST on February 3rd.
Upper bell canyon reported a peak wind gust of 60 knots between 0000 and 0100 on February 4th.
Pleasants Peak reported a peak wind gust of 59 knots at 0800 PST on February 4th.
Fremont Canyon had a peak wind gust of 68 knots at 1100 PST on February 4th.
Freezing temperatures occurred in the High Desert overnight on February 4th and into the morning hours on February 5th. Low temperatures ranged from 17 degrees to 28 degrees.
The Inland Empire experienced below freezing temperatures overnight on the 4th into the morning of the 5th. Low temperatures ranged from 30 to 40 degrees.
The San Diego valleys experienced below freezing temperatures overnight on February 4th into the morning on February 5th. Low temperatures ranged from 20 to 30 degrees.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in California in 2020Every state in 2020This day in weather historyWarnings in California, February 2020
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: 879088, 879089, 879090, 879091, 879092, 879093, 879094, 879095, 879097, 879098.