Another round of gusty Santa Ana winds impacted sections of Ventura and Los Angeles counties. Peak wind gusts between 60 and 71 MPH were reported.
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.
Another round of gusty Santa Ana winds impacted sections of Ventura and Los Angeles counties. Peak wind gusts between 60 and 71 MPH were reported.
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 7, 1:51 PM PST, 2 minutes earlier.
Area Forecast Discussion
National Weather Service Los Angeles/Oxnard CA
151 PM PST Mon Dec 7 2020
.SYNOPSIS...07/150 PM.
There will be moderate to strong Santa Ana winds through Tuesday
with dry conditions across the region and high temperatures
several degrees above normal. A cooling trend is expected
Wednesday with all areas back to normal temperatures by the end of
the week. Some warming expected over the weekend.
&&
.SHORT TERM (TDY-THU)...07/135 PM.
Strong Santa Ana wind event in progress this afternoon, strongest
in LA/Ventura Counties but also impacting parts of SLO/SB
Counties as well, mainly in the hills. What makes this event
unique and potentially more dangerous is that it's impacting areas
that are typically sheltered during Santa Ana's. The reason being
an upper low that is traversing the area from north to south
today is producing more of an easterly component to the winds,
which historically has favored more widespread wind coverage in
Ventura County and perhaps less so across the majority of the San
Fernando Valley and the Santa Monica Mtns, most of which has been
relatively light so far (generally under 35 mph).
Forecast through Tuesday and beyond remains largely unchanged.
Winds will continue through tonight and into Tuesday morning,
before weakening Tuesday afternoon. Gradients forecast to peak
Tuesday morning so in some areas, mostly SLO/SB counties the
strongest winds have to arrive. Not expecting any temporary sea
breeze this evening so east winds will hold through the night and
keep temps fairly moderated from the very cold morning readings
we've had the last few days. Wind protected locations will still
get cold but those will be smaller in areal coverage and tricky to
predict. Highs Tuesday fairly warm as the upper low and its colder
air shift to the south and the thicker high clouds over us today
move away as well. Likely many areas in the low to mid 80s.
Remainder of the week looks fairly quiet and benign. Wednesday
still very lightly offshore but trending onshore and cooler for
coast/valleys. Then much cooler Thursday with the first real
decent onshore day in the last couple weeks. Possibly even some
marine layer return and temps dropping back into the 60s.
.LONG TERM (FRI-MON)...07/146 PM.
Still cool with onshore flow Friday and possibly some marine layer
to start off. Both the GFS and ECMWF showing varying degrees of
high pressure coming in over the weekend into early next week,
the EC being the strongest with also some offshore flow. However,
ensembles are decidedly against the offshore idea so while we
should see some warming it likely will be fairly minimal and just
a few degrees above seasonal norms. Will monitor the offshore
potential but given the relatively few number of ensembles
supporting that it looks unlikely at this time.
&&
.AVIATION...07/1720Z.
At 1659Z at KLAX, there was no marine layer. The top of the
surface based inversion was near 1300 feet with a temperature of
17 C.
High confidence in cig/vis forecast.
Moderate confidence in wind forecast. East winds are possible at
all airports and could be up to 10 kt stronger than fcst (XCP at
KLAX and KSMO where the max possible east wind is approx 8
knots).
Periods of moderate to strong LLWS and turbulence are possible.
KLAX...High confidence in cig/vis forecast. Any east wind
component should be less than 8 knots. There is a 30 percent
chance of ocnl LLWS and turbulence.
KBUR...High confidence in cig/vis forecast. There is a 30 percent
chance of ocnl LLWS and turbulence.
&&
.MARINE...07/913 AM.
Across the outer waters...Moderate to high confidence in Small
Craft level winds until late tonight, except through Tuesday
afternoon for NE winds in zone PZZ676. A large NW swell is
forecast to move into the region bringing Small Craft level seas
late today into tonight. Moderate to high confidence in waves
above 10 ft through the outer waters, and Small Craft Advisories
will likely be needed as seas remain elevated. Small Craft level
winds look likely Thursday and Friday.
Across the inner waters north of Pt. Sal...Moderate to high
confidence in Small Craft Advisory winds and seas. Small Craft
Advisory may be extended to cover increased seas through
Wednesday.
Across the inner waters south of Point Conception...High confidence
in Small Craft Advisory level winds for eastern portions of the
Santa Barbara Channel starting today, with moderate confidence in
winds increasing to gales in the afternoon. Highest confidence in
gale force winds for the nearshore waters off Point Mugu to Santa
Monica today. Small craft level winds are likely following the
end of the Gale Warning.
A large, long period west to northwest swell will affect all
waters late Monday through early Wednesday, then will slowly
diminish but stay elevated through late in the week. The swell
will peak on Tuesday at 14 to 17 feet off the Central Coast and
to 6 to 9 feet from Santa Barbara to Orange County. This will
create hazardous breaking waves near shore, including the Morro
Bay and Ventura Harbor entrances. While this long period swell
will be dominant, there will also be short period waves on top
of it where the gusty NE winds are blowing.
&&
.BEACHES...07/916 AM.
A large and long period west to northwest swell will move through
the coastal waters Monday afternoon through Wednesday. The
forerunner waves will have periods longer than 20 seconds Monday
afternoon through early Tuesday. Breaking waves of 16 and 22 feet
will arrive along the Central Coast during the peak of the surf
on Tuesday, with surf of 6 to 12 feet with local sets to 15 feet
along portions of the beaches of Los Angeles, Ventura, and 5 to 8
feet along southern Santa Barbara counties.
Surf of 20 feet and greater can damage coastal structures like
piers and jetties, so a High Surf Warning has been issued for the
Central Coast. Otherwise, High Surf Advisories are in effect for
the remaining beaches. Dangerous rip currents will develop at
most beaches. Widespread northeast to east winds will occur
this morning through early Tuesday afternoon as well, especially
Monday afternoon through Tuesday morning, which could amplify some
waves. Vulnerable harbor entrances such as Morro Bay and Ventura
have a history of dangerous breaking waves under such conditions.
High tides should stay below 5 feet during the event, so the
threat of coastal flooding is minimal.
&&
.FIRE WEATHER...07/129 PM.
No changes expected to the current Red Flag Warnings today, except
to extended the warning for the mountains of San Luis Obispo and
Santa Barbara Counties through 10PM Tuesday.
Moderate to strong northeast to east winds will continue over
areas that typically see offshore winds, but also impacting some
areas that usually do not like much of San Luis Obispo and Santa
Barbara Counties. The strongest winds are expected now into early
Tuesday when gusts between 30 and 50 mph will be common over
parts of all four counties, except for gusts between 50 and 70 mph
expected over select foothills over all four counties as well the
Los Angeles and Ventura County Mountains. Humidities will lower
further tonight, and be 5 to 10 percent nearly everywhere by
Tuesday, with very poor if any overnight recoveries. With the
current state of the extremely dry fuels, moderate to strong
winds, and low humidities, Red Flag Warnings will be in effect
over most areas by this afternoon and continue through Tuesday.
While winds will weaken later Tuesday through Wednesday, they will
remain locally breezy with gusts between 20 and 35 mph in the
windier locations especially Tuesday night. Humidities will stay
very low through Wednesday, resulting in elevated to near critical
conditions. The threat for additional Red Flag Warnings is
decreasing for Thursday through Saturday.
&&
.LOX WATCHES/WARNINGS/ADVISORIES...
CA...High Surf Advisory in effect until 9 PM PST this evening for
zones 34-35. (See LAXCFWLOX).
Wind Advisory in effect until 9 AM PST Tuesday for zones
34-51. (See LAXNPWLOX).
High Surf Warning in effect from 9 PM this evening to 9 PM
PST Wednesday for zones 34-35. (See LAXCFWLOX).
Wind Advisory in effect from 6 PM this evening to 9 AM PST
Tuesday for zones 35-36-39. (See LAXNPWLOX).
High Surf Advisory in effect from 6 PM this evening to 9 PM
PST Wednesday for zone 39. (See LAXCFWLOX).
Wind Advisory in effect until noon PST Tuesday for zones
40-41-44-45-52-88-547. (See LAXNPWLOX).
High Surf Advisory in effect from 9 PM this evening to 9 PM
PST Wednesday for zones 40-41-87. (See LAXCFWLOX).
Wind Advisory in effect until 6 PM PST this evening for zone
46. (See LAXNPWLOX).
High Wind Warning in effect from 6 PM this evening to noon
PST Tuesday for zone 46. (See LAXNPWLOX).
High Wind Warning in effect until noon PST Tuesday for zones
53-54. (See LAXNPWLOX).
Red Flag Warning in effect until noon PST Tuesday for zones
234>236-239. (See LAXRFWLOX).
Red Flag Warning in effect until 10 PM PST Tuesday for zones
240-241-244>246-251>254-288-547-548. (See LAXRFWLOX).
PZ...Small Craft Advisory in effect until 3 AM PST Tuesday for
zones 645-670-673. (See LAXMWWLOX).
Gale Warning in effect until noon PST Tuesday for zones
650-655. (See LAXMWWLOX).
Small Craft Advisory in effect until 3 PM PST Tuesday for
zone 676. (See LAXMWWLOX).
&&
.HAZARD POTENTIAL OUTLOOK (THU-MON).
No significant hazards expected.
&&
PUBLIC...MW
AVIATION...Sweet/Rorke
MARINE...Sweet/PHILLIPS
BEACHES...Sweet/Kj
FIRE...Kittell
SYNOPSIS...MW
weather.gov/losangeles2 high wind. Local standard time, as filed.
Strong and gusty Santa Ana winds impacted the mountains of Los Angeles county. Some peak north to northeast wind gusts include: Warm Springs (Gust 71 MPH), Magic Mountain Truckway (Gust 66 MPH) and Chilao (Gust 64 MPH).
Strong and gusty Santa Ana winds impacted the mountains of Ventura county. Observations from the local mesonet network indicated north to northeast winds, gusting up to 65 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: 937264, 937265.