Strong and gusty Santa Ana winds buffeted sections of Ventura and Los Angeles counties. North to northeast winds, gusting between 58 and 85 MPH, were reported in the mountains and valleys.
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 LOX wrote it up.
Strong and gusty Santa Ana winds buffeted sections of Ventura and Los Angeles counties. North to northeast winds, gusting between 58 and 85 MPH, were reported in the mountains and valleys.
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 Los Angeles, CA wrote its last area forecast discussion before the first event at Dec 2, 10:41 PM PST, 19 minutes earlier.
Area Forecast Discussion...UPDATED
National Weather Service Los Angeles/Oxnard CA
1041 PM PST Wed Dec 2 2020
.SYNOPSIS...02/913 PM.
Gusty northeast winds are expected through the rest of the week
and continue into next week. Damaging gusts are likely over the
mountains and foothills of Los Angeles and Ventura Counties on
Thursday with critical fire weather concerns. It will remain dry
across the region with temperatures above normal.
&&
.SHORT TERM (WED-SAT)...02/925 PM.
The latest satellite imagery shows a tilted omega block ridge
centered over the state and extending into the northern
Intermountain Region. An upper-level trough on the front side of
the ridge will dig south through Arizona through Thursday, while
another trough near 44N and 144W slams into the back side of the
ridge. A cold air mass dropping south with the trough to the east
will tighten the offshore pressure gradient while adding some wind
support for the strong Santa Ana wind event that is setting up.
Winds have been picking up across Los Angeles and Ventura Counties
this evening and a few locations are already pushing into
damaging wind gust criteria. Local damaging wind gusts will become
more widespread tonight across the mountains and the Santa Clarita
Valley. Humidities and dewpoints are are crashing this evening as
offshore flow strengthens and drier air spreads in. The current
headlines look agreeable and no updates are planned at this time.
The forecast will be updated to tweak temperatures slightly for
Thursday.
Along the Central Coast, patches of stratus has pushed into the
area as enough westerly flow remains. Any stratus that forms will
likely form as dense fog tonight. The ridging building an offshore
flow redeveloping along the Central Coast should wipe out stratus
after midnight. If stratus does linger into sunrise Thursday, it
should scour rather quickly as offshore winds will start to mix
down.
An update will be issued shortly for stratus tonight along the
Central Coast and to tweak temperatures on Thursday.
***From Previous Discussion***
As mentioned previously models have scaled back the offshore flow
Thursday night and Friday and it's very unlikely we'll see
warning level winds for a second night and day. In fact, many
areas will likely drop below advisory levels Thursday afternoon
and stay that way through Friday, though it will still be breezy
at times, especially during the typical late night/early morning
increase. No wind hazards are currently in effect for that period
but it's possible a few low end advisories may be needed.
Temps warmed up nicely today at the coast with the offshore flow
and Camarillo actually came close to tying a record with the 85
there. The cold advection coming in tonight should knock that
down a few degrees Thursday with mostly 70s at lower elevations.
And cold overnight again in wind protected areas like the Ojai
Valley, SLO/SB Counties, and the Antelope Valley. Probably even
colder Thursday night into Friday with less wind and even drier
air. MOS guidance numbers in the teens for the AV and that looks
reasonable so a Hard Freeze Watch has been issued to the extreme
cold there and possibilty of damaged agriculture and pipes. And
similarly cold temps expected again Friday night.
Offshore flow to continue into the weekend but gradients and upper
support will continue to weaken so winds will be weaker and more
isolated. Slightly warmer daytime temps, especially inland as cold
air shifts east.
.LONG TERM (SUN-WED)...02/204 PM.
Sunday looks to be a fairly quiet weather day with light offshore
flow, cool morning temps but mild in the afternoon. Then things
get a little tricky Monday as both operational GFS/ECMWF models
now showing a back door upper low moving in from the north with
the actual low center almost right overnight Monday morning. The
models are dry with it at lower levels with just some high clouds.
But the GFS generates a wide area of 50+ kt winds at 850mb and a
LAX-DAG gradient of almost -7mb. The EC has a similar gradient but
the EC ensembles are quite a bit weaker with the surface winds.
So still some uncertainty and it's likely we'll still see quite a
bit of model fluctuation in the track of that low as we get
closer. But suffice it to say that it looks like there will be
another increase in Santa Ana winds early next week, potentially
to another strong event. Winds expected to drop off later Tuesday
into Wednesday.
&&
.AVIATION...03/0640Z.
At 0505Z at KLAX, there was no marine layer. There was a sfc based
inversion with top near 800 feet and a temperature of 22 C.
High confidence in CAVU TAFs (except for KSMX and KSBP) with
moderate confidence in wind speeds and timing for NE winds across
LA and Ventura Counties. Moderate turbulence is possible over and
near higher terrain. LLWS up to 20 kt is also possible.
Low Confidence in KSMX and KSBP TAFs with 1/4SM FG VV002 conds
possible through 16Z.
KLAX...High confidence in CAVU TAF. There is a 20% chance of a 6
to 8 kt east wind component 12Z-19Z. 10 KT of LLWS possible
through 22Z.
KBUR...High confidence in CAVU TAF. Possible Moderate turbulence
or 15 KT of LLWS at times.
&&
.MARINE...02/923 PM.
Outer Waters... Good confidence that Small Craft Advisory (SCA)
level hazardous seas of 10 feet will develop by mid-morning
Thursday across the northern portions before spreading to NW of
San Nicolas Island by late Thursday morning or early afternoon.
Hazardous seas will then likely last through Friday afternoon.
Otherwise, seas should lower to below SCA thresholds through
early next week.
Inner Waters north of Point Sal...SCA level hazardous seas are
likely to develop Thursday morning and continue through Friday
afternoon. Winds are not expected to reach SCA thresholds. Peak
seas will likely reach 10 feet. The combination of a long periods
swell, could cause some higher steep waves near shore.
Inner Waters S of Point Conception...For the waters near shore
from Point Mugu to Santa Monica gusty NE winds are expected
through Thursday evening and will likely reach as far offshore as
the Channel Islands. There is a chance that gusty NE winds may
impact east-facing harbors such as Avalon Harbor and Two Harbors
on Catalina Island Thursday morning.
&&
.LOX WATCHES/WARNINGS/ADVISORIES...
CA...High Surf Advisory in effect from 6 AM Thursday to 10 PM PST
Friday for zones 34-35. (See LAXCFWLOX).
Wind Advisory in effect until 3 PM PST Thursday for zones
40-41-44-45-547. (See LAXNPWLOX).
High Surf Advisory in effect from 2 PM Thursday to 2 AM PST
Saturday for zones 40-41-87. (See LAXCFWLOX).
High Wind Warning in effect until 3 PM PST Thursday for zones
46-53-54-88. (See LAXNPWLOX).
Hard Freeze Watch in effect from Thursday evening through
Friday morning for zone 59. (See LAXNPWLOX).
Red Flag Warning in effect until 6 PM PST Friday for zones
240-241-244-245-547-548. (See LAXRFWLOX).
Red Flag Warning in effect until 10 PM PST Saturday for zones
246-253-254-288. (See LAXRFWLOX).
PZ...Small Craft Advisory in effect from 9 AM Thursday to 6 PM PST
Friday for zones 645-670-673-676. (See LAXMWWLOX).
Small Craft Advisory in effect until 8 PM PST Thursday for
zones 650-655. (See LAXMWWLOX).
&&
.HAZARD POTENTIAL OUTLOOK (SAT-WED).
Periods of offshore winds and dry conditions could lead to
brief critical fire weather conditions Saturday and again early
next week. High surf or strong rip currents may create hazardous
ocean conditions early next week. Overnight lows in the teens in
the Antelope Valley Saturday morning could cause damage to
agriculture and exposed pipes. Near freezing conditions over
coastal Santa Barbara and San Luis Obispo Counties may damage
sensitive plants and crops this weekend.
&&
PUBLIC...Hall/MW
AVIATION...Rorke
MARINE...Stewart
SYNOPSIS...Stewart
weather.gov/losangelesPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
729 PM PST WED DEC 2 2020
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0710 PM NON-TSTM WND GST 9 NE SAN FERNANDO 34.39N 118.34W
12/02/2020 M61 MPH LOS ANGELES CA MESONET
MESONET STATION SE678 MAGIC MTN TRUCK TRL
(SCE).
&&
HALLPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
736 PM PST WED DEC 2 2020
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0730 PM NON-TSTM WND GST 3 N MOORPARK 34.33N 118.87W
12/02/2020 M60 MPH VENTURA CA MESONET
MESONET STATION SE277 HAPPY CAMP RD (SCE).
&&
HALLPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
951 PM PST WED DEC 2 2020
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0910 PM HIGH SUST WINDS 1 NNW CHATSWORTH 34.29N 118.60W
12/02/2020 M42 MPH LOS ANGELES CA MESONET
MESONET STATION SE712 BROWNS CYN (SCE).
&&
HALLPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
1006 PM PST WED DEC 2 2020
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0910 PM HIGH SUST WINDS 1 NNW CHATSWORTH 34.29N 118.60W
12/02/2020 M42 MPH LOS ANGELES CA MESONET
MESONET STATION SE712 BROWNS CYN (SCE).
0853 PM HIGH SUST WINDS 8 ESE CASTAIC LAKE 34.60N 118.58W
12/02/2020 M42 MPH LOS ANGELES CA MESONET
MESONET STATION WMSC1 WARM SPRINGS RAWS.
&&PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
1015 PM PST WED DEC 2 2020
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0955 PM NON-TSTM WND GST 5 NNE SAN FERNANDO 34.35N 118.42W
12/02/2020 M62 MPH LOS ANGELES CA MESONET
MESONET STATION CNIC1 CAMP NINE RAWS.
&&
HALL3 high wind. Local standard time, as filed.
Strong and gusty north to northeast winds impacted the Los Angeles County Mountains. Some peak wind gusts include Magic Mountain Truckway (Gust 85 MPH), Camp Nine (Gust 62 MPH) and Chilao (Gust 60 MPH).
Strong and gusty north to northeast winds impacted the Ventura County Mountains. The local mesonet network indicated gusty up to 70 MPH.
Strong and gusty north to northeast winds impacted the Santa Monica Mountains. The local mesonet indicated wind gusts in excess of 60 MPH with the Boney Mountain sensor reporting gusts up to 77 MPH.
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, December 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: 937262, 937263, 937261.