192
FXUS66 KLOX 070505
AFDLOX

Area Forecast Discussion
National Weather Service Los Angeles/Oxnard CA
905 PM PST Wed Nov 6 2024

.SYNOPSIS...06/231 PM.

Strong offshore flow between a surface high in the Great Basin
and a surface trough in the southern California bight will
continue gusty northeasterly winds and critical fire weather
conditions through Thursday. A warm up in temperatures will occur
for late week as the pattern relaxes. A series of weak storm
systems will bring cooler weather over the weekend.

&&

.SHORT TERM (WED-SAT)...06/309 PM.

***PARTICULARLY DANGEROUS SITUATION (PDS) RED FLAG WARNINGS
 UNFOLDING ACROSS MUCH OF LOS ANGELES AND VENTURA COUNTIES!***

A very strong Santa Ana wind event developed early this morning
across parts of LA and Ventura Counties. Gradients to the east
peaked around around -8mb and with strong upper level support to
the tune of 55-65kt close to 900mb as well as decent cold air
advection winds had no trouble pushing down to the surface and
well out over the coastal waters. Peak gusts in the mountains were
between 75 and 85 mph while at lower elevations winds were in the
45-65 mph range. Even Camarillo airport reported a gust to 62 mph.
Winds are starting to drop off now but still gusting between 30
and 45 mph with still some gusts in the 60s in the mountains.

Gusty winds are expected to continue into the evening with another
offshore push expected Thursday morning. With less upper support
aloft the winds are not expected to be quite as strong as this
morning but still expecting gusts to 60+ in the mountains and
below some of the favored canyons and passes in LA/Ventura
Counties. High wind warnings are in effect through Thursday
afternoon across much of LA/Ventura Counties.

With colder and very dry air over the region now, overnight
temperatures will drop quickly in wind protected areas,
especially north of Pt Conception, Ojai Valley, and in the
Antelope Valley. May need frost or freeze hazards later tonight.
Highs Thursday should be a little warmer as the cold aloft starts
to moderate.

Winds are expected to settle down later Thursday with more typical
weather conditions Fri/Sat with highs in the 70s to low 80s.

.LONG TERM (SUN-WED)...06/323 PM.

A weak trough will pass through the state Sunday but no precip
expected locally as currently none of the ensembles are indicating
any rain from it. In fact, very little impact expected except
possibly a slight cool down early next week.

A slightly stronger trough is on tap for next Wednesday, though
again this one will mainly move north and east of the area. There
are some solutions showing some light rain across the northern
mountains as it passes by, but the main impact may be another
Santa Ana wind event for next Wed/Thu after it passes through.
Several EC ensembles show increasing winds during this period and
both the EC and GFS indicate LAX-DAG gradients increasing to
around -6mb. So far not seeing any solutions that are anywhere
close to the strength of the current Santa Ana but a return of at
least some moderate offshore wind gusts is possible.

&&

.AVIATION...06/1934Z.

Around 11Z, there was no marine layer depth at KLAX. There was
surface-based inversion up to around 2400 feet with a temperature
near 15 degrees Celsius.

Moderate confidence in the current forecast. Significant east wind
gusts are expected for most terminals south of Pt Conception.
There is a currently a large fire in Ventura County contributing
to FU casuing low vis and cigs at VTA County sites. Maximum wind
gusts may be off by +/- 10 kts. Moderate to strong LLWS and
turbulence is possible at all sites thru the period.

KLAX...VFR conditions are expected through the period. There is a
30 percent chance of moderate to strong low-level wind shear and
turbulence through 20Z. There is a 30 percent chance of east winds
between 8 and 10 knots and a 10 percent chance of east winds
greater than 10 knots through the period, with best chances thru
10Z Thurs.

KBUR...VFR conditions are expected through the period. There is a
40 percent chance of strong low-level wind shear and turbulence
through 20Z.

&&

.MARINE...06/845 AM.

For the Outer Waters, Small Craft Advisory (SCA) level winds and
seas near or above 10 feet are likely much of the time through
this afternoon. For the southern outer waters (PZZ676) especially
from the Channel Islands out to San Nicolas Island, expect Gale
Force gusts in the eastern portion of the zone into Thursday
afternoon. Otherwise, conds are expected to drop below SCA levels
thursday afternoon through Friday night, with a 30-40% chance of
SCA level winds Saturday afternoon thru Sunday.

For the Inner Waters along the Central Coast, wind and seas are
expected to remain under SCA criteria levels through Sunday.

For the Santa Barbara Channel, through the early afternoon hours
Thursday, expect NE to E STORM FORCE WINDS from Pt. Mugu CA to
Santa Cruz Island, including a corridor of 20 NM to the north and
south along this line, including the nearshore waters. Conds are
then expected to be below SCA levels Thursday night through
Saturday. Then, there is a 30% chance for SCA level winds in the
afternoon/evening hours Saturday and Sunday. Very rough seas are
expected due to a combination of longer period west swell with
short period easterly wind waves.

For the Southern Inner Waters, expect SCA to STORM FORCE level NE
to E winds for the waters from Point Mugu to Santa Monica and out
to Santa Cruz Island, with SCA to GALE FORCE winds in the San
Pedro Channel through Thursday afternoon. Conditions will be
strongest early Wednesday morning into the afternoon, and again
early Thursday morning thru early afternoon. Local gusts up to 50
knots are likely (70-80% chance) nearshore below canyons and
passes from Pt. Mugu CA to Santa Cruz Island, including a corridor
of 20 NM to the north and south along this line. There is a (50-60%
chance) of 35 knot gusts in the San Pedro Channel and out to
Catalina Island. Hazardous and choppy seas of at least 5 to 7 feet
will be possible during the peak winds, with very rough
conditions due to a combination of longer period west swell with
the short period easterly wind waves. Conds are then expected to
be below SCA levels Thursday night through Sunday night.

&&

.FIRE WEATHER...06/1136 AM.

*****ALL AREAS IN PDS RED FLAG WARNING WILL NOW HAVE PDS GOING
 UNTIL 9 AM TOMORROW/THURSDAY MORNING*****

***PARTICULARLY DANGEROUS SITUATION (PDS) RED FLAG WARNINGS
 UNFOLDING ACROSS MUCH OF LOS ANGELES AND VENTURA COUNTIES!***

*****EXTREMELY CRITICAL PDS RED FLAG WARNING CONDITIONS
 UNFOLDING*****

A very strong, widespread, and long-duration Santa Ana wind event
will bring widespread Extremely Critical fire weather conditions
to many areas of Los Angeles and Ventura counties Wednesday into
Thursday. This will be a PARTICULARLY DANGEROUS SITUATION (PDS)
Red Flag Warning event in many areas, with the combination of
strong upper level wind support, tightening offshore pressure
gradients (LAX-Daggett peaking at -7 to -8 mb), and moderate cold
air advection. The strongest winds with this Santa Ana wind event
are expected to be Wednesday morning into Wednesday night when
widespread damaging wind gusts of 60 to 80 mph are likely in the
mountains and foothills of Los Angeles and Ventura Counties
(including the Santa Monicas and Santa Susanas), with isolated
gusts of 80 to 100 mph possible in favored areas of the San
Gabriels. Similar winds are expected once again in the mountains
Thursday night. For wind prone coastal and valley areas of Los
Angeles and Ventura counties, damaging gusts of 50 to 70 mph will
be likely (including the Malibu Coast and Ventura County coastal
plain). Due to the strong upper level wind support, typical wind
sheltered areas such as portions of the LA basin all the way to
the coast, Lake Casitas and Ojai, as well as the Channel Islands
and Catalina Island are expected to see gusty north to northeast
winds with associated Red Flag conditions. Humidity levels are
also expected to lower to between 8 to 15 percent by Wednesday
afternoon with these low humidities likely to linger into Thursday
and Friday.

These are Extremely Critical and highly volatile conditions. Any
new fires in the Red Flag Warning area -- and especially the PDS
Red Flag Warning area -- will have rapid fire spread, extreme
fire behavior, and long range spotting.

In addition, there will be gusty north to northeast winds
overlapping with humidities around 10 to 20 percent late this
afternoon into tonight across the mountains and foothills of San
Luis Obispo and Santa Barbara counties, as well as the Santa Ynez
mountains, Santa Barbara south coast, and Highway 33 corridor.
These areas are under a Red Flag Warning for late today into
tonight, with gusts of 35 to 55 mph being common, except isolated
gusts up to 60 mph.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...Freeze Watch remains in effect until 9 AM PST Thursday for
      zones 38-343-344-383. (See LAXNPWLOX).
     Wind Advisory remains in effect until 4 PM PST Thursday for
      zones 87-356-357-366>368-381-382-548. (See LAXNPWLOX).
     High Surf Advisory in effect until 4 PM PST Thursday for zone
      87. (See LAXCFWLOX).
     High Wind Warning remains in effect until 4 PM PST Thursday
      for zones 88-354-355-358-362-369>380-550. (See LAXNPWLOX).
     Dense Smoke Advisory in effect until 9 AM PST Thursday for
      zones 354>356-358-369-374. .
     Red Flag Warning in effect until 6 PM PST Thursday for zones
      288-354>358-362-366>368-371>374-381-382-548. (See LAXRFWLOX).
     Red Flag Warning in effect until 11 AM PST Friday for zones
      369-370-375>380. (See LAXRFWLOX).
PZ...Gale Warning in effect until 4 PM PST Thursday for zone 676. (See LAXMWWLOX).

&&

$$

PUBLIC...MW
AVIATION...Lewis
MARINE...Lewis/Smith/black
FIRE...COHEN
SYNOPSIS...MW/Hall

weather.gov/losangeles

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