High Wind in California, January 22 to 23, 2023

Area Forecast Discussion
National Weather Service Los Angeles/Oxnard CA
222 PM PST Sun Jan 22 2023

.SYNOPSIS...22/216 PM.

A potent low pressure system grazing the region will support gusty
offshore winds to many areas through Monday with offshore winds
possibly returning by Thursday. Temperatures will warm to near
normal for many areas by midweek as a ridge builds into the
region.

&&

.SHORT TERM (TDY-WED)...22/218 PM.

The latest satellite showed sunny skies save for some clouds
offshore as well as building low clouds across interior north
facing mountain slopes near the Kern County border. The low clouds
with patchy fog will pivot northward into interior San Luis Obispo
county while slowly dissipating tonight. Otherwise clear skies
will prevail through at least Tuesday and likely longer due a
prolonged period of offshore flow. Where winds are light at night,
frost may once again be a concern each night through at least
Monday

We are on track for a fairly strong north to northeast wind event
this afternoon through Monday afternoon. A powerful jet streak
peaking near 160 mph will slide down the backside of a sharp
trough digging south from the Great Basin into the Desert
Southwest U.S. Associated strong descent and cold air advection
coupled with moderate to strong offshore gradients (Santa Barbara
to Bakersfield gradient has just peaked at strong gradient of
-6.5 mb!) will support advisory level winds for much of Santa
Barbara, Ventura, and Los Angeles counties with warning level
winds peaking in the 60 to 75 mph range across the higher
mountains, likely highest across the Los Angeles mountains. The
strongest winds for Santa Barbara and mountains of Ventura County
is expected through this evening. North winds will transition
northeast this evening into Monday with the strongest winds
transitioning closer to a typical Santa Ana, although hardest hit
areas will be a bit further south than typical. A capping
inversion around 600 mb and the strong jet nearby increases the
threat for damaging mountain wave induced winds across the
foothills of LA County tonight through early afternoon Monday.
Given relatively low confidence in the strongest winds surfacing,
will stick with the Wind Advisory for coasts and valleys of Los
Angeles and Ventura Counties during this time, but did highlight
the potential for local gusts to around 60 mph in foothill to
lower mountain slopes, potentially including foothill communities
Glendora to La Canada Flintridge. Lingering moisture from recent
rainfall may increase the chances for downed trees and power lines
where the strongest winds occur.

The upper low departs by Tuesday with lingering northwest flow
aloft and weak offshore gradients into Wednesday. Advisory level
offshore winds are possible in windier Santa Ana corridors during
this time frame. Waning cold air advection should allow
temperatures to rebound to near normal by Wednesday with the
warmest areas possibly reaching 70 degrees.

.LONG TERM (THU-SUN)...22/218 PM.

Above average confidence in dry conditions through Saturday,
although there is some indication of a pattern change next weekend
as the Climate Prediction Center paints southwest California in an
area of near to above normal precipitation in the 6-10 day
period).

Until then it appears we are on track for a moderate Santa Ana
Thursdayish as surface high pressure setting up over the Rockies
may peak near a strong 1050 mb thanks in part to the impressive
snowpack across the region. The associated moderate to strong
offshore gradient and cold air advection looks to be the main
driver of Thursday's Santa Ana event as the upper pattern is not
nearly as potent. This event may be more traditional in terms of
areas impacted and the diurnal peak in winds (early morning to
mid afternoon).

The stubborn ridge across the Eastern Pacific ocean largely
responsible for the recent dry weather may nose into the region
by Friday before showing signs of breaking down heading into the
weekend. Perhaps a sign that we could be shifting away from the
dry weather pattern.

&&

.AVIATION...22/1954Z.

At 1921Z at KLAX, there was no marine layer nor an inversion.

Moderate confidence in the 18z TAFs. VFR conditions are expected
through the period.

Lower confidence in winds, especially after 14Z. Moderate to
strong LLWS and UDDFS may develop anywhere in the next 24 hours.
Timing of wind changes and magnitude of winds could require some
amendments.

KLAX...Low confidence in TAF. LLWS and UDDFS are possible during
the period. There is a 40-50 percent chance of gusty north winds
overnight tonight. There is a 30% chance of winds shifting more
east (040-060 deg) 04-10Z and an 8-10 kt east wind component.

KBUR...Low confidence in TAF due to winds. LLWS and UDDFS are
possible during the period. There is 30 percent chance of stronger
winds than forecast after 10z Monday.

&&

.MARINE...22/220 PM.

No changes to the marine forecast in the afternoon issuance.

For all the outer waters and along the Central Coast, there is a
80-90% chance of northwest winds reaching Gale Force this
afternoon and tonight near Point Conception and beyond 30 NM from
the coast.

Late tonight into Monday, there is a 60-70% chance of SCA NE
winds extending to the outer waters south of Santa Cruz Island
and even reaching out to San Nicolas Island late tonight. There
is a 20-30% chance of northeast winds increasing to Gale Force
late tonight and decreasing below SCA by late Monday morning.
Winds for all the waters should decrease by Monday mid- morning
and will likely remain below SCA levels through Wednesday.

Hazardous seas will increase to 10+ feet across the outer waters
today and last into Monday afternoon. There is a 40% chance of
seas reaching 10 feet again on Tuesday.

For the Santa Barbara Channel, NW winds will reach SCA levels
late this morning through this evening across the western portion.
There is a 30-40% chance of SCA level north wind gusts nearshore
from Santa Barbara to Rincon Beach this afternoon into evening.
There is a 50-60% chance of SCA NE winds from this evening into
late tonight in the nearshore waters south of Ventura, with a 20%
chance of increasing to Gale Force.

For the waters from Point Mugu out past Anacapa Island and
southward to Palos Verdes, NE winds will increase to Gale Force
later this afternoon and last through the night. Winds will shift
north Monday morning and be more focused from Malibu into the
Santa Monica Bay and then decrease to SCA by the afternoon. There
is a 30% chance that SCA level N winds continue through Monday
afternoon. There is a 30-40% chance of SCA level winds from Point
Mugu to Malibu Monday night into Tuesday morning. Short period,
hazardous seas can be expected with the gusty winds. Gusty
offshore winds may return to the inner waters around Thursday.

For the waters south of the Palos Verdes Peninsula and into the
San Pedro Channel, NE winds will increase to at least SCA level
winds with short-period seas.

&&

.BEACHES...22/221 PM.

Moderate confidence in the current forecast. An abnormally high
astronomical tide will continue the threat of minor tidal overflow
and minor beach erosion through the weekend. A BEACH HAZARDS
STATEMENT remains in effect through this evening. There is a
moderate (30-40 percent) chance it will need to be extended for
some areas with building surf between Sunday and Tuesday.

A building northwest swell will likely bring high surf to the
west and northwest facing beaches of the Central Coast.
There is a moderate (40-60 percent) chance that the HIGH SURF
ADVISORY could be extended through Wednesday.

Killed the high surf advisory for now. The west facing beaches of
Ventura County may see high surf Tuesday and Wednesday of the
upcoming week. There is a only a 20 percent chance that west
facing beaches of the Santa Barbara South Coast and Los Angeles
county reach High Surf Advisory criteria.

A mix of gusty winds and steep short- period seas will bring
hazardous marine conditions to the majority of the coastal waters
today into at least Monday morning. East- facing harbors such as
Avalon Harbor and Two Harbors should not be considered as safe
harbor as there is a 50-60 percent chance that easterly winds of
15 to 25 knots and wind waves of 3 to 5 feet could enter east-
facing harbors, probably by around 10 pm tonight. The peak of the
event will probably be over by about 10-11 am Monday after a
secondary maximum of wind comes through around 7-8 am Monday.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...High Wind Warning in effect until 9 PM PST this evening for
      zones 53-352-353. (See LAXNPWLOX).
     Wind Advisory in effect until 6 PM PST this evening for zone
      54. (See LAXNPWLOX).
     High Wind Warning in effect from 6 PM this evening to 2 PM
      PST Monday for zone 54. (See LAXNPWLOX).
     Beach Hazards Statement in effect until midnight PST tonight
      for zones 87-340-346-349-350-354-362-364. (See LAXCFWLOX).
     Wind Advisory in effect until 2 PM PST Monday for zones
      88-358-359-362-363-547-548. (See LAXNPWLOX).
     High Surf Advisory in effect until 10 PM PST Monday for zones
      340-346. (See LAXCFWLOX).
     Wind Advisory in effect until 9 PM PST this evening for zones
      349>351-356. (See LAXNPWLOX).
     Wind Advisory in effect from 7 PM this evening to 4 AM PST
      Monday for zones 354-355. (See LAXNPWLOX).
PZ...Small Craft Advisory in effect until 10 PM PST this evening
      for zone 645. (See LAXMWWLOX).
     Small Craft Advisory in effect until 3 AM PST Monday for zone
      650. (See LAXMWWLOX).
     Small Craft Advisory in effect until 9 PM PST this evening
      for zone 655. (See LAXMWWLOX).
     Gale Warning in effect from 9 PM this evening to 9 AM PST
      Monday for zone 655. (See LAXMWWLOX).
     Gale Warning in effect until 10 PM PST this evening for zones
      670-673-676. (See LAXMWWLOX).

&&

PUBLIC...Munroe
AVIATION...Sweet/Lund
MARINE...Sweet/Lund
BEACHES...Sweet/Lund
SYNOPSIS...Munroe

weather.gov/losangeles

Experimental Graphical Hazardous Weather Outlook at:
https://www.weather.gov/erh/ghwo?wfo=lox