High Wind in California, November 7 to 9, 2023

Area Forecast Discussion
National Weather Service Los Angeles/Oxnard CA
542 PM PST Tue Nov 7 2023

.SYNOPSIS...07/314 PM.

A cooling trend with a mix of clouds and sun is expected across
the region today with periods of gusty west to northwest winds and
isolated to scattered showers as a cold front brushes the area.
The winds will turn northerly tonight into Wednesday and bring
gusty winds across southern Santa Barbara County and through the
Interstate 5 Corridor. A warming and drying trend will develop
Wednesday and continue into the weekend as offshore flow is
prevalent. Gusty Santa Ana winds will blow into Thursday and
Friday. A storm system could affect the region as early as early
next week.

&&

.SHORT TERM (TUE-FRI)...07/310 PM.

Some clouds remain over the Los Angeles Basin and up into the
mountains this afternoon as the tail end of a weakening cold
front brushes the area. Upper-level troughing to the north of the
area will move over the region into Wednesday. Showers could
develop across the San Fernando and San Gabriel Valleys and up
into the San Gabriel Mountains this afternoon and evening as
enough moisture in place could interact with a jet streak and
remnants of the frontal boundary. Any amounts will likely be less
than a quarter of an inch.

The main story will be the winds across the region over the next
several days. A cold air mass to the north will develop surface
high pressure and develop a tightening northerly surface
gradient across the area. Gusty northerly winds will develop
across southern Santa Barbara County and through the Interstate 5
Corridor tonight. Wind Advisory headlines are issued for most of
the winds affected by northerly winds through 3 AM PST Wednesday.
ECMWF EFI values highlights the Montecito Hills area as an
elevated potential for gusty winds between tonight and Wednesday.
Isolated gusts to 60 mph are possible in the hills above
Montecito.

The winds will shift around to the northeast tonight and develop
an offshore flow pattern over the coming days. Gusty Santa Ana
winds will develop between late tonight and Wednesday morning.
Wind Advisories have been issued for most areas across the
Southland between Wednesday morning and Thursday morning. Winds
will ramp up rapidly across eastern Ventura County, western Los
Angeles County, and up into the mountains. While wind headlines go
into Thursday, there is a good chance that winds will weaken some
or become localized during the late afternoon and early evening
hours across the advisory area. However, winds will likely expand
quickly across the area again into late Wednesday evening and
possibly be a tad stronger across portion of the area. An
advisory might be needed for the remaining Ventura County coastal
areas during this time period. Gusty Santa Lucia winds could also
develop between Wednesday night and Thursday morning across
western San Luis Obispo County.

With the offshore flow pattern developing, a warming and drying is
expected to take shape over the coming days. Temperatures go above
NBM values into Friday in the forecast to highlight the potential
for compressional heating taking place.

In wind-sheltered areas and interior valleys, cold overnight
temperatures are expected especially Wednesday night and Thursday
nights. There is a high chance that frost/freeze headlines might
be needed for these nights.

.LONG TERM (SAT-TUE)...07/312 PM.

After a front falls apart north the area between Friday and
Saturday, an offshore flow pattern will get some reinforcement.
There is a slight uptick in the winds, but the forecast ensembles
suggest this could be a weak to locally moderate offshore flow
event. With less wind, the air mass will likely stagnate and heat
up. Temperatures for Saturday looks mostly reasonable, but the
forecast high temperatures for Sunday break away from NBM values.

Offshore flow should break down between Sunday and Monday. The
latest deterministic solutions back up the idea of cooling
advertised by majority of the forecast ensembles. Deterministic
solutions of the GFS and ECMWF suggest southwest flow aloft
developing on Sunday, which should bring some semblance of a
marine influence back into the forecast. A return of low clouds
as dense fog could develop between Sunday night and Monday.

Broad troughing over the West Coast early next week and as the
previous discussion stated, "All eyes on a possible storm system
next week." Very agreement is coming into view on wet weather
pattern developing for middle to late portion of next week across
the area. While it is early, a vast majority of the EPS, GEFS,
and CMC solutions develop precipitation across the region. At some
point next week, it is looking wet, the only questions that
remain in when and how much? The exact timing is still unknown for
beginning and ending, and there are still much divergence in the
ensemble QPF values. The forecast keeps NBM value during this
period for now.

&&

.AVIATION...08/0142Z.

At 0017Z at KLAX, no marine layer or inversion was present.

Moderate to high confidence in the 00Z coast and vly TAFs. There
is a 60% chance of IFR/MVFR cigs at KPRB late tonight into Wed
morning. Otherwise, VFR conds are expected at the airfields thru
Wed morning. Moderate confidence in timing and strength of gusty
north/northeast winds for KOXR, KCMA, KSMO, KBUR and KVNY. These
areas may see llws at times.

High confidence in the 00Z desert TAFs with VFR conds thru Wed
morning. Gusty W winds will continue this evening, and redevelop
again tomorrow after 17Z.

KLAX...High confidence in the 00Z TAF. VFR conds are expected
thru the fcst period. East winds are possible from 07Z to 19Z, and
the east wind component should remain below 10 kt.

KBUR...Moderate to high confidence in the 00Z TAF. VFR conds are
expected thru the fcst period. Gusty N to NE winds will be
possible along with llws after 10Z tonight.

&&

.MARINE...07/228 PM.

For the outer waters, moderate to high confidence in the current
forecast. Winds will intensify late this afternoon with Gales
mainly from Point Conception south thru later tonight with Small
Craft Advisory (SCA) level winds elsewhere. SCA conds will then
continue for much of the central and southern outer waters thru
late this week.

For the nearshore coastal waters along the Central Coast,
moderate to high confidence in the current forecast. Winds are
expected to increase to SCA levels this afternoon through tonight.
Conds will then remain below SCA levels Wednesday through Sunday.

For the inner waters south of Point Conception, moderate
confidence in the current forecast. There is a SCA for the entire
Santa Barbara Channel through tonight, with a 20 percent chance
of Gale gusts near the islands thru the evening hours. In
addition, shorter period seas will build to 6-8 feet in this area.
Gusty winds are also expected over the inner waters west of L.A.
County, with SCA level W-NW winds into this evening.

Gusty northeast winds are expected over the waters between
Oxnard and Malibu and out to San Nicolas Island from early
Wednesday morning through Thursday. The strongest gusts are
expected nearshore with a 20 percent chance of reaching gale force
each morning.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...Wind Advisory in effect from 3 AM Wednesday to 11 AM PST
      Thursday for zones 88-362-369-370. (See LAXNPWLOX).
     Wind Advisory in effect until 3 AM PST Wednesday for zones
      349>353-356-376-377-381-383. (See LAXNPWLOX).
     Wind Advisory in effect from 6 AM Wednesday to 11 AM PST
      Thursday for zones 355-358-371>374. (See LAXNPWLOX).
     Wind Advisory in effect from 3 AM Wednesday to 2 PM PST
      Thursday for zones 375-379-380. (See LAXNPWLOX).
     Wind Advisory in effect until 11 AM PST Thursday for zone
      378. (See LAXNPWLOX).
     Fire Weather Watch in effect from late Wednesday night
      through Thursday afternoon for zones 288-358-362-369>380. (See LAXRFWLOX).
PZ...Small Craft Advisory in effect until 3 AM PST Wednesday for
      zones 645-650-655. (See LAXMWWLOX).
     Small Craft Advisory in effect until 3 AM PST Thursday for
      zone 670. (See LAXMWWLOX).
     Gale Warning in effect until 3 AM PST Wednesday for zones
      673-676. (See LAXMWWLOX).

&&

PUBLIC...Hall
AVIATION...Phillips
MARINE...Sirard
SYNOPSIS...Hall

weather.gov/losangeles

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