Strong and gusty north to northeast winds impacted the mountains of Santa Barbara, Ventura and Los Angeles counties. Wind gusts up to 81 MPH were reported in some areas.
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 north to northeast winds impacted the mountains of Santa Barbara, Ventura and Los Angeles counties. Wind gusts up to 81 MPH were reported in some areas.
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 Apr 21, 9:40 PM PST, 7 minutes earlier.
Area Forecast Discussion...UPDATED
National Weather Service Los Angeles/Oxnard CA
1040 PM PDT Tue Apr 21 2020
updated aviation discussion
.SYNOPSIS...21/808 PM.
High pressure over the area this week will keep the region dry
with mostly clear skies. Daytime high temperatures will approach
records Thursday, and remain warm into the weekend. Gusty
northerly winds are expected for parts of the region this week
including the Interstate 5 Corridor, southern Santa Barbara County
and the coastal waters with winds peaking late Wednesday and
Thursday.
&&
.SHORT TERM (TUE-FRI)...21/802 PM.
***UPDATE***
Many areas are experiencing moderate to locally strong northwest
to north winds this evening. A 1032 surface high is over the
waters west of Point Conception, with weak low pressure over the
Southern California Bight. This pressure gradient is causing the
northerly winds, which are strongest along the SBA South Coast
and Santa Ynez foothills, where gusts from 35 to 49 mph have been
occuring. In addition, gusts of 40 to 50 mph are affecting the
Interstate 5 Corridor near the Grapevine, with some local gusts to
40 mph observed near Saugus. In the Antelope Valley, west winds of
15 to 25 mph with local gusts to 45 mph are likely to continue
through much the night.
Otherwise, clear skies are expected overnight for much of the
area, except for a chance of patchy fog or low clouds in the
Salinas Valley late tonight into Wednesday morning.
***From Previous Discussion***
At upper levels, ridge will persist just off the West Coast through
Friday. Near the surface, moderate to locally strong northwest to
north flow is forecast.
Forecast-wise, the main issue in the short term will continue to
be northerly winds. 12Z models still indicate good northerly offshore
gradients through the period with peak gradients Wednesday night
through Friday. Some peak forecast gradients include LAX-BFL (-6.6
MB), SBA-SMX (-4.1 MB) and SBA-BFL (-5.3 MB). With these types of
gradients, solid advisory level northerly winds are likely across
the Santa Ynez Range and I-5 Corridor. On Wednesday night and Thursday,
models indicate 850 MB winds 45-55 knots which will enhance northerly
winds. So, warning levels gusts are possible Wednesday night and Thursday
through the Santa Ynez Range and I-5 Corridor. So for the afternoon
forecast, will go with WIND ADVISORIES for the Santa Ynez Range and
I-5 Corridor now through Wednesday evening and a HIGH WIND WATCH for
Wednesday night and Thursday. Additionally, advisories may be needed
for some other areas Wednesday night/Thursday (Santa Clarita/San
Fernando Valleys and the Santa Monica Mountains). However, will let
future shifts consider the need for advisories in these areas.
Check LAXNPWLOX for the current slate of wind advisories and watches.
The most pressing secondary issue in the short term will be
temperatures. With the upper ridge just offshore and the northerly
flow, a dramatic warming trend is expected through Friday. For
Wednesday/Thursday, many areas will be 10-15 degrees above seasonal
normals with even more warming on Friday (with the potential for
some record-breaking high temperatures). Given the time of year and
the still relatively cool overnight low temperatures, no need for
any heat products. However, it will be an impressive little heat wave
and people need to take the proper precautions.
.LONG TERM (SAT-TUE)...21/200 PM.
For the extended, 12Z models continue to exhibit good synoptic
agreement. At upper levels, ridge gets flattened by a weak trough
Saturday through Monday, but rebuilds on Tuesday. Near the
surface, northerly offshore flow will gradually decrease with weak
onshore flow to the east.
Forecast-wise, no significant issues expected through the period.
With the weak upper level trough, there may be some partly cloudy
this weekend (due to some high clouds), but no coastal low clouds
or fog is anticipated. Northerly winds will continue through the
period, but will be noticeably weaker and there will be some weak
onshore winds each afternoon and evening. As for temperatures, a
gradual cooling trend is expected Saturday through Monday with
some rebound on Tuesday. However, even on the coolest day (likely
Monday), afternoon high temperatures will still be several degrees
above seasonal normals.
&&
.AVIATION...22/0538Z.
At 05Z at KLAX, there was a weak inversion. The base was near 400
ft and the top was near 1400 ft with a temperature of 18 degrees
C.
High confidence in VFR conditions at all sites through the period.
However, there is a slight chance of patchy fog at KPRB by early
morning. Moderate confidence in winds as gusty N to NW winds will
likely impact most sites but lower confidence in speeds. LLWS and
turbulence will be likely through the period, especially near
higher terrain.
KLAX....High confidence in 06Z TAF in terms of VFR conditions,
moderate confidence in winds. There is a chance of gusty north
winds late Wednesday night. Any east wind component is likely to
be under 6 kt. UDDFS and LLWS are possible.
KBUR...High confidence in 06Z TAF in terms of VFR conditions,
moderate confidence in winds. Gusty N to NE winds in the vicinity
with UDDFS and LLWS possible.
&&
.MARINE...21/743 PM.
Moderate confidence in the current forecast. Widespread moderate
to strong NW winds will affect much of the waters through Thursday
evening. Gales between Point Conception and San Nicolas Island
will continue through Wednesday afternoon, before spreading north
over the outer waters west of the Central Coast. Gales are also
likely over the western Santa Barbara Channel by Wednesday
evening, and should also continue through Thursday evening. Lower
confidence in the SBA Channel forecast as winds may subside below
Gale force at times. For the remainder of the waters, including
nearshore off the Central Coast, winds will likely be strong SCA
level, but with a chance of Gale Force gusts. For the nearshore
waters off the LA Coast, SCA winds are likely Wednesday night
through Thursday night.
Although portions of the Santa Monica Bay may not see SCA level
winds, SCA level seas will likely affect much of the western
portions of the waters inside the southern California bight. For
the remainder of the waters, hazardous short period seas are
expected with heights near or above ten feet over the outer
waters.
&&
.LOX WATCHES/WARNINGS/ADVISORIES...
CA...Wind Advisory in effect until 9 PM PDT Wednesday for zones
39-52>54. (See LAXNPWLOX).
High Wind Watch in effect from Wednesday evening through
Thursday afternoon for zones 39-52>54. (See LAXNPWLOX).
PZ...Small Craft Advisory in effect until 9 PM PDT Friday for zone
645. (See LAXMWWLOX).
Gale Watch in effect through Thursday evening for zone 650. (See LAXMWWLOX).
Small Craft Advisory in effect until 3 PM PDT Wednesday for
zone 670. (See LAXMWWLOX).
Gale Watch in effect from Wednesday afternoon through late
Thursday night for zone 670. (See LAXMWWLOX).
Gale Warning in effect until 9 PM PDT Thursday BELOW 7500
FEET for zones 673-676. (See LAXMWWLOX).
&&
.HAZARD POTENTIAL OUTLOOK (FRI-TUE).
Gusty northerly winds may cause driving hazards at times
Wednesday night through Thursday night. There is a high potential
for the first heat wave of the season that will peak later this
week. Highs temperatures in the Los Angeles County coastal and
valley areas could reach into the lower 90s by Friday and
Saturday. Overnight lows in the warmest areas will be in the mid
60s.
&&
PUBLIC...Thompson
AVIATION...Stewart
MARINE...Smith
SYNOPSIS...Phillips
weather.gov/losangeles4 high wind. Local standard time, as filed.
Strong and gusty northerly winds impacted the Santa Ynez Mountains as well as the South Coast of Santa Barbara county. The RAWS sensor at Montecito reported wind gusts up to 81 MPH.
Strong and gusty northerly winds impacted the Santa Ynez Mountains as well as the South Coast of Santa Barbara county. The RAWS sensor at Montecito reported wind gusts up to 81 MPH.
Strong and gusty north to northeast winds impacted the mountains of Los Angeles county. Some wind reports from automated observation stations include Sandberg (gusts to 68 MPH), Warm Springs (gusts to 64 MPH) and Whitaker Peak (gusts to 69 MPH).
Strong and gusty north to northeast winds impacted the mountains of Ventura county. Wind gusts up to around 60 MPH were reported.
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, April 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: 888552, 888553, 888554, 888555.