Santa Ana Winds and dense fog were reported November 20-22.
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 SGX wrote it up.
Santa Ana Winds and dense fog were reported November 20-22.
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 Nov 19, 9:21 PM PST, 5 hours 32 minutes earlier.
Area Forecast Discussion
National Weather Service San Diego CA
921 PM PST Fri Nov 19 2021
.SYNOPSIS...
A trough passing by to the north through Saturday will bring daytime
temperatures near or below seasonal averages, onshore flow and night
and morning low clouds and fog west of the mountains. High pressure
building over Utah Saturday evening will bring gusty Santa Ana winds
Saturday night through Sunday, weakening on Monday. Highs will be in
the 80s in many coastal and valley areas Sunday and Monday. Tuesday
and Wednesday will be a little cooler with a chance for light
precipitation over and west of the mountains as a weak trough moves
across the area. Surface high pressure moving into the Great Basin
could bring another spell of Santa Ana conditions next Thursday.
&&
.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
Evening Update:
Expanded the areas of fog expected overnight to include all of the
coastal and valley areas, although not expecting widespread dense
fog to occur due to the high clouds and higher altitude of the
marine layer. No other changes were needed to the forecast this
evening.
Plentiful high clouds continue to stream across the region meanwhile
low stratus clouds have formed across the coastal waters and pushing
past the coastal strip and into the inland valleys. There are areas
of light fog along with the low stratus across coastal and valley
areas.
The offshore flow will develop by Saturday afternoon and increase
through Sunday, with Red Flag conditions still looking likely during
the day Sunday for the most prone Santa Ana locations below passes
and on the coastal mountain slopes in the Northern Inland Empire,
Riverside County Mountains, Santa Ana Mountains, and Inland Orange
County.
Previous Forecast Discussion (issued at 138 PM PDT):
As the trough to our north progresses inland through Saturday
morning, the flow aloft begins to split with most of the energy
attached to the trough moving over the Great Basin while a nearly
stationary closed low forms about 950 miles southwest of San Diego.
This will maintain the onshore flow and the marine layer presence,
with low clouds and fog west of the mtns through Sat morning. Areas
of fog could again extend into the inland valleys. Temperatures will
begin to trend slightly upward as weak northerly winds begin to
develop Saturday afternoon.
For Saturday night and Sunday, the sfc pressure gradients turn
strongly offshore as a high moves into the Great Basin following the
upper trough. This will set up a moderate Santa Ana event with warm
and dry offshore flow raising Sunday's temps into the low to mid 80s
west of the mountains. Northeasterly winds from 20-30 mph in the
mountain passes and the Inland Empire below the Cajon Pass will gust
to 45-55 mph. Wind gusts in the San Diego County foothills and
inland Orange County will be more in the 40-50 mph range. The winds
will weaken and become more localized Sunday night into Monday as
the sfc high moves southeast out of the Great Basin and pressure
gradients weaken. A sea breeze will likely develop Monday afternoon
so areas closer to the coast won't be as warm as on Sunday.
As we head into Tuesday, another trough from the Gulf of Alaska
approaches the west coast. This will cause the closed low to our
southwest to become an open wave as it gets pulled into the mean
northwesterly flow. With reinforcing cold air from the northwest, we
get an area of broad troughing extending from western Canada to
northern mexico by Tue afternoon. This will bring a sharp cool-down
on Tue, with daytime temps mostly in the 60s to low 70s west of the
mtns. The marine layer will also make a return as the flow turns
onshore, with low clouds and fog extending into the inland valleys
Tue and Wed mornings. This trough could also bring a chance for
light precip from the coastal slopes to the beaches.
Offshore flow and a weak ridge moving in from the west will likely
bring warmer and drier weather for Thanksgiving day and Fri but
details are uncertain due the spread in the solutions of the various
ensemble members.
&&
.AVIATION...
200345Z...Coast/Valleys...Areas of BKN-OVC low clouds will continue
to develop within 20 miles of the coast this evening and spread up
to 35 miles inland, including west and south parts of the Inland
Empire by 11Z Sat. Cloud bases will be mostly 1000-1400 ft MSL with
tops to 1700 ft MSL. Areas of vis 3-5 miles in BR will occur in the
through 18Z Sat with local vis below 1 mile in BR/FG in the valleys
08Z-17Z Sat. Most areas will clear 16Z-19Z Sat with SCT-BKN high
clouds above 20000 feet MSL prevailing Sat afternoon and evening.
Stratus will be less extensive Sat night but with lower cloud bases.
Mountains/Deserts...SCT-BKN high clouds above 20000 feet MSL with
unrestricted vis will continue through Sat evening.
&&
.MARINE...
No hazardous marine conditions are expected through Wednesday.
&&
.FIRE WEATHER...
Light northerly flow will develop Saturday morning bringing warm,
dry weather to the inland valleys. Gusty north winds from 25-35 mph
will be mostly confined below the Cajon Pass. Santa Ana winds will
strengthen Saturday night into Sunday with peak gusts Sunday morning
from 45-55 mph. Winds on Monday will become more localized and
weaken into the afternoon with gusts from 30-35 mph. Winds will be
strongest through and below passes and on coastal mountain slopes.
Sunday and Monday will be warm and dry with minimum relative
humidity from 5 to 15% from the valleys to the deserts. Humidity
along the coast will be closer to 20 to 25% resulting in elevated
fire weather conditions with critical conditions in the windy areas.
Higher humidity will spread further inland Tuesday and Wednesday. A
passing low pressure system has the potential to bring light rain or
drizzle to the coast, valley and mountain areas Tuesday night into
Wednesday morning.
&&
.SKYWARN...
Skywarn activation is not requested. However weather spotters are
encouraged to report significant weather conditions.
&&
.SGX WATCHES/WARNINGS/ADVISORIES...
CA...Red Flag Warning from 9 AM to 7 PM PST Sunday for Orange County
Inland Areas-Riverside County Mountains-Including The San
Jacinto Ranger District Of The San Bernardino National
Forest-San Bernardino County Mountains-Including The
Mountain Top And Front Country Ranger Districts Of The San
Bernardino National Forest-San Bernardino and Riverside
County Valleys -The Inland Empire-San Gorgonio Pass Near
Banning-Santa Ana Mountains-Including The Trabuco Ranger
District of the Cleveland National Forest.
PZ...NONE.
&&
PUBLIC/FIRE WEATHER...PG/JMB
AVIATION/MARINE...MaxwellThe national radar mosaic for the moment the first event began.
9 high wind, 4 dense fog, 2 heat. Local standard time, as filed.
Ontario Airport reported visibility of 1/8 mile in dense fog.
Chino Airport reported one-quarter mile visibility in dense fog.
Ramona Airport reported one-quarter mile visibility in dense fog.
Corona Airport reported one-quarter mile visibility in dense fog.
Newport Beach broke the high temperature record for November 21, reaching a high of 85 degrees, breaking the previous record of 84 degrees set in 1998.
Vista broke the high temperature record for November 21, reaching a high temperature of 89 degrees, breaking the previous record of 88 degrees set in 2015.
CSU San Bernardino (SCE809) reported a peak wind gust of 57 mph.
Muscoy (SCE599) reported a peak wind gust of 52 mph.
Shandin Hills (039 SE) reported a peak wind gust of 52 mph.
Devil Canyon (SCE125) reported a peak wind gust of 53 mph.
Fontana (SCE157) reported a peak wind gust of 53 mph.
Mesonet site Arrowhead Springs (189SE) reported a peak wind gust of 67 mph.
Duncan Canyon (SCE533) reported a peak wind gust of 58 mph.
Sill Hill reported a peak wind gust of 57 mph.
Fremont Canyon reported a peak wind gust to 55 mph.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in California in 2021Every state in 2021This day in weather historyWarnings in California, November 2021
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: 990114, 990115, 990117, 990116, 991074, 991075, 990097, 990111, 990107, 990109, 990101, 990098, 990105, 990103, 990095.