Gusty Santa Ana winds occurred across Southern California the evening of December 8 through December 10. The peak wind gust of the event was 73 MPH at Marshall Peak (San Bernardino County Mountains).
Every event with a place to put it; 6 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.
Gusty Santa Ana winds occurred across Southern California the evening of December 8 through December 10. The peak wind gust of the event was 73 MPH at Marshall Peak (San Bernardino County Mountains). The Elm Fire spread under windy conditions and burned for two days near the San Gorgonio Pass.
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 Dec 8, 8:16 PM PST, 3 hours 44 minutes earlier.
Area Forecast Discussion
National Weather Service San Diego CA
816 PM PST Fri Dec 8 2023
.SYNOPSIS...
High pressure building over the Great Basin this weekend will bring
sunny days, clear nights and gusty northeast Santa Ana winds to the
mountains, foothills, and valleys. The strongest winds will be on
Saturday. The warmest day will be Sunday. This dry weather pattern
will continue through next week.
&&
.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
Santa Ana winds were starting to surface this evening in the San
Bernardino Mountains and Foothills, in and below the Cajon Pass, the
San Gorgonio Pass and the Santa Ana Mountains. Peak gusts through 8
PM included 43 mph at Fontana, 41 mph at Lytle Creek, 39 mph at
Devore, 38 mph at Pleasants Peak in the Santa Ana Mountains and at
CSU San Bernardino.
The winds will peak Saturday when a 1042 mb high settles over
Nevada. Pressure gradients will be strong enough to generate winds
gusts of 40-60 mph in the Santa Ana wind-prone areas below the Cajon
Pass and in the Santa Ana Mountain canyons. Wind Advisories are in
effect for the mountains and valleys.
The offshore gradient weakens Saturday night and Sunday morning and
the winds will gradually subside through Sunday afternoon. There
will be a few degrees of cooling Monday and Tuesday, then another
offshore pressure pattern sets up the middle of next week for more
dry and mild weather through Friday.
&&
.AVIATION...
090430Z...Mostly clear through Saturday. Strong northeast winds will
develop first in passes and foothills, spreading into some valley
corridors overnight and eventually into some coastal corridors
Saturday morning. Strongest gusts 50-60 knots in foothills. Areas of
moderate up/downdrafts and LLWS expected. Winds will weaken after
23Z Saturday, but continue breezy in these areas.
&&
.MARINE...
Some northeast or east wind gusts around 20 knots can be expected
Saturday. These can happen anywhere in the coastal waters, but are
most likely near Camp Pendleton and at the Mexico border. Otherwise,
no marine weather hazards are expected through Wednesday.
&&
.FIRE WEATHER...
...Red Flag Warning will be in effect beginning 8 AM on Saturday
morning, and running through Sunday afternoon for the Inland
Empire...
Strong and gusty northeasterly winds will develop tonight and peak
in strength on Saturday morning. Strongest winds will be below the
Cajon Pass, and near Fremont Canyon, where a few gusts of 65 MPH or
more are possible. Elsewhere, in the Inland Empire and along the
coastal slopes of the mountains in wind-prone areas, east to
northeast winds will be 30 to 40 MPH, with peak gusts 50 to 55 MPH
from early Saturday morning, through Sunday morning. Minimum RH
values will fall to around ten percent by Saturday afternoon, and
again on Sunday afternoon, with poor overnight recovery. This will
create areas of elevated, to critical fire weather conditions at
times in the valleys. Due to drier conditions at lower elevations
north of San Diego County, more widespread critical fire conditions
are expected in the Inland Empire.
Winds will remain in the 25-35 MPH range with peak gusts in the
Santa Ana wind-prone areas of 50-60 MPH through Sunday morning, then
weaken later in the day. Widespread RH values on Sunday will once
again fall to around ten percent away from the coast.
Light winds are expected on Monday and Tuesday, allowing some
moderation in relative humidity and cooling west of the mountains.
&&
.SGX WATCHES/WARNINGS/ADVISORIES...
CA...Red Flag Warning from 8 AM Saturday to 3 PM PST Sunday for San
Bernardino and Riverside County Valleys -The Inland Empire.
Wind Advisory from 10 AM Saturday to 3 PM PST Sunday for
Riverside County Mountains-San Diego County Mountains-San
Diego County Valleys-San Gorgonio Pass Near Banning.
Wind Advisory until 3 PM PST Sunday for Orange County Inland
Areas-San Bernardino County Mountains-Santa Ana Mountains
and Foothills.
PZ...None.
&&
PUBLIC...Moede
FIRE WEATHER...10
AVIATION/MARINE/BEACHES...MMThe national radar mosaic for the moment the first event began.
5 high wind, 1 wildfire. Local standard time, as filed.
Gusty Santa Ana winds occurred across the San Gorgonio Pass on December 9. The following are the strongest wind gusts across the zone:
Banning (SCE1645): 64 MPH.|Banning (SCE700): 60 MPH.|Beaumont: 58 MPH.
Gusty Santa Ana winds occurred across the San Diego County Valleys on December 9. The following are the strongest wind gusts across the zone:
Alpine RAWS: 64 MPH.|Hauser Mountain: 59 MPH.
Gusty Santa Ana winds occurred across the Inland Empire December 9 through the morning on December 10. The following are the strongest wind gusts across the zone:
Devil Canyon: 67 MPH.|Fontana: 66 MPH.|Highland Springs: 65 MPH.|Fontana: 65 MPH.|Rancho Cucamonga: 63 MPH.|CSU San Bernardino: 63 MPH.|Lytle Creek: 61 MPH.|Devore: 61 MPH.|Lytle Creek Wash: 59 MPH.|Wildwood Park: 58 MPH.|Devore: 58 MPH.
Gusty Santa Ana winds occurred across the San Bernardino County Mountains on December 9. Marshall Peak recorded a peak wind gust of 65 MPH.
Gusty Santa Ana winds occurred across the Santa Ana Mountains and Foothills on December 9. The following are the strongest wind gusts across the zone:
Fremont Canyon: 67 MPH.|Pleasants Peak: 59 MPH.
The Elm Fire started at 9:21 AM on December 9 under gusty Santa Ana wind conditions. By the evening on December 10, the fire grew to 65 acres but was 80% contained. The fire reached full containment by 12:35 PM on December 11.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in California in 2023Every state in 2023This day in weather historyWarnings in California, December 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: 1152496, 1152497, 1152498, 1152499, 1152495, 1152500.