Van Nuys, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

855
FXUS66 KLOX 140402
AFDLOX

Area Forecast Discussion
National Weather Service Los Angeles/Oxnard CA
802 PM PST Mon Jan 13 2025

.SYNOPSIS...13/133 PM.

Moderate to strong offshore flow will remain in place through
Wednesday with a dry air mass across the region. An extended
period of critical fire weather conditions will continue across
Southland through midweek due to the combination of gusty winds,
very low humidities, and a lack of rainfall. Cold overnight
temperatures are expected in wind protected areas for the next
few mornings. A cooling trend with higher humidities is expected
beginning Thursday and lasting through the weekend.

&&

.SHORT TERM (TDY-THU)...13/212 PM.

The seemingly endless stretch of offshore flow continues today
with gusts between 30-50 mph across the usual Santa Ana corridor
areas of LA/Ventura Counties. Expecting this to continue through
early evening. Then overnight a reinforcing surge of offshore
flow is expected following another trough passing through the
Great Basin. Models are indicating that this next surge will have
a stronger northerly component to it, but also a stronger easterly
component as well, so most of the same areas that were windy today
should be 10-20 mph stronger than today with peak gusts around 75
mph across in the mountains.

Wednesday morning the NAM and some of the higher res models are
indicating some additional strengthening of the winds as upper
support and gradients increase. However, the EC ensembles are
trending a little lighter Wednesday so somewhat lower confidence
for that time frame. In any case, gusty Santa Ana winds are
expected to continue through Wednesday, but decreasing no later
than the afternoon as gradients start to weaken.

Significant weakening of the winds expected Thursday, and in fact
many areas will receive an onshore wind by afternoon which should
also bring some increasing humidities to the area to aid in the
firefighting efforts.

On a different topic, the current upper level pattern has ushered
in a very cold air mass and both afternoon and overnight
temperatures have dropped from recent days. And some interior
area temperatures (Antelope Valley, far interior SLO County)
dropped below 20 degrees last night. Expecting at least another
couple of nights of that and likely even colder tonight than last
night with lows between 12 and 16 in some areas. These would not
be records as those are in the single digits across the AV and 12
for Paso Robles. In any event, there are a number of freeze and
frost headlines in effect.

.LONG TERM (FRI-MON)...13/226 PM.

Thankfully there is high confidence in a quiet period of weather
with relatively light onshore winds Friday through the weekend and
much improved humidities. Friday should be the coolest today with
moderate onshore flow in place and possibly even some morning low
clouds and fog. Morning stratus will likely extend into the
weekend but rising heights and thicknesses along with weakening
onshore flow should lead to at least a slight warming trend.

Still some concerns for next Monday and/or Tuesday as models show
another inside slider trough moving through the Great Basin. EC
ensemble solutions are mixed but so far leaning towards a light to
possibly low end moderate Santa Ana event. The upper level pattern
for this weekend and early next week has been exhibiting quite a
bit of jumping around so confidence is on the lower side still.
Some earlier ensemble solutions had even indicating a small chance
of rain during this period but more recent solutions have steered
drier.

&&

.AVIATION...14/0245Z.

At 00Z at KLAX, there was no marine layer nor inversion.

Expecting VFR conditions for TAF sites with gusty N to NE winds
are expected to affect much of the forecast area, especially sites
in Ventura and LA County. There will be areas of LLWS, and
moderate to locally strong UDDF and turbulence, especially near
the foothills and mtns. Winds may be erratic at times, changing
quickly between gusty and light.

KLAX...High confidence in VFR conds thru the period. However,
there is a 10% chance of 4-5SM FU and/or bkn025 smoke layer at any
point. There is a 30-40% chance of an east wind component
reaching 8 kt tonight with best chances from 14Z and 19Z.

KBUR...High confidence in the CAVU TAF. Moderate confidence in
winds. Maximum wind gusts may be off +/- 10 kts and wind group
changes may be off +/- 3 hours. LLWS is likely, especially after
00Z through 18Z. Moderate to locally strong turbulence and UDDF
will also impact the terminal during the period.

&&

.MARINE...13/132 PM.

In the Outer Waters, Small Craft Advisory (SCA) level E to NE
winds will persist in the southern zone (PZZ676) and eastern
portions of the central zone (PZZ673) thru Wednesday morning and
late tonight, respectively. There is a 30-40% chance for E to NE
SCA winds to return Tuesday through Wednesday in the southeastern
portion of the central zone. Local Gale force gusts are possible
(20% chance) through Tuesday morning, with slightly greater
chances in the southern Outer Waters (30-40% chance) late Tuesday
night through Wednesday morning. Seas will be at or above SCA
levels thru this evening for zones PZZ673 and PZZ670. Conds will
be below SCA levels Wednesday night thru Friday morning, then a
30-40% chance of SCA level NW winds Friday morning through late
night from Point Conception south to San Nicolas Island.

In the inner waters N of Pt. Sal, except for a 20% chance of SCA
level NE winds nearshore during the morning hours Tuesday and
Wednesday, SCA level conds are not expected thru Friday night.

In the Santa Barbara Channel, Gale force winds are expected much
of the time from Ventura to eastern Santa Cruz Island southward
through Wednesday afternoon. Winds may drop below Gale force to
SCA levels at times through Wednesday, especially Tuesday
evening. SCA level NE winds may continue into Wednesday evening,
then benign conds are expected Wednesday night thru Friday night.
Elsewhere, there is a 20% chance of SCA level E winds late tonight
thru Wednesday morning.

In the southern inner waters. Gale force winds are expected from
Malibu to Point Mugu and out to Anacapa Island much of the time
thru Wednesday afternoon, though winds may drop below Gale force
at times, especially Tuesday evening. Then, SCA level NE winds
will likely continue into Wednesday evening. Elsewhere, SCA level
NE winds are likely at times thru Wednesday afternoon. This is
especially likely (70% chance) thru the San Pedro Channel out to
Avalon and Two Harbors on Catalina Island this afternoon, and
again during the late night thru morning hours tonight thru Wed.
There is a 30% chance of Gale Force winds thru the San Pedro
Channel to Catalina Island during those periods thru Wednesday
afternoon, with best chances Wednesday morning. Benign conds are
then expected Wednesday night through Friday.

&&

.BEACHES...13/132 PM.

Another round of moderate to locally strong Santa Ana Winds have
made it to the region, creating hazardous conditions nearshore and
through the San Pedro Channel. Through tonight and again late
Tuesday into Wednesday afternoon, NE to E winds may create large
breaking waves to Avalon and Two Harbors, creating hazardous
conditions and possible minor coastal flooding, with highest
chances Wednesday morning.

&&

.FIRE WEATHER...13/432 PM.

...PARTICULARLY DANGEROUS SITUATION (PDS) RED FLAG WARNING IN
EFFECT 4 AM TUESDAY UNTIL NOON WEDNESDAY DUE TO DAMAGING
NORTHEAST TO EAST WINDS AND LOW HUMIDITIES FOR THE FOLLOWING
AREAS: WESTERN SAN GABRIEL MOUNTAINS/ I5 CORRIDOR/ SOUTHERN
VENTURA COUNTY MOUNTAINS/ SANTA SUSANA MOUNTAINS/ VENTURA VALLEYS
(MAINLY NEAR SIMI VALLEY/MOORPARK/ SANTA PAULA/SOUTH MOUNTAIN)/
WESTERN SANTA MONICAS/ WESTERN SAN FERNANDO VALLEY (MAINLY
HIGHWAYS 118/210 CORRIDORS FROM PORTER RANCH TO SAN FERNANDO)/
CALABASAS/AGOURA HILLS/ VENTURA COUNTY COASTAL PLAIN--THIS WILL
BE A TIME PERIOD OF LOCALLY DAMAGING WINDS WITH EXTREMELY
CRITICAL FIRE WEATHER CONDITIONS...

...RED FLAG WARNINGS IN EFFECT FOR MUCH OF LOS ANGELES AND
VENTURA COUNTIES THROUGH 6 PM WEDNESDAY DUE TO GUSTY NORTHEAST TO
EAST WINDS AND LOW HUMIDITIES...

...RED FLAG WARNING REMAINS IN EFFECT FROM 10 PM THIS EVENING TO
NOON PST WEDNESDAY FOR GUSTY EAST WINDS AND LOW HUMIDITY FOR THE
MOUNTAINS OF SANTA BARBARA AND SAN LUIS OBISPO COUNTIES AS WELL AS
SANTA YNEZ MOUNTAINS EASTERN RANGE, LAKE CASITAS, AND OJAI
VALLEY...

***THIS IS A PARTICULARLY DANGEROUS SITUATION (PDS) FOR PORTIONS
  OF LOS ANGELES AND VENTURA COUNTIES!***

.DISCUSSION...
.A long duration Red Flag Warning remains in effect across much
of Los Angeles and Ventura counties through 6 PM Wednesday, expanding
into the mountains of San Luis Obispo and Santa Barbara counties
by tonight. THERE WILL LIKELY BE DAMAGING WINDS GUSTING BETWEEN
55 AND 70 MPH ACROSS PORTIONS OF THE RED FLAG WARNING AREA FROM
EARLY TUESDAY MORNING THROUGH WEDNESDAY MORNING, LEADING TO THE
PDS RED FLAG WARNING UPGRADE. AREAS IN THE RED FLAG WARNING
(ESPECIALLY DURING THE PDS TIME FRAME) WILL HAVE A HIGH RISK FOR
LARGE FIRES WITH VERY RAPID FIRE SPREAD, EXTREME FIRE BEHAVIOR,
AND LONG RANGE SPOTTING. WHILE DANGEROUS PDS RED FLAG FIRE WEATHER
CONDITIONS ARE LIKELY WITH THIS EVENT EARLY TUESDAY MORNING INTO
WEDNESDAY MORNING, THIS WIND EVENT IS NOT EXPECTED TO BE AS STRONG
AND DESTRUCTIVE AS LAST WEEK`S WINDSTORM. Due to the more
easterly component of the wind, much of Ventura County will likely
have stronger winds than the offshore wind events this past week.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...Freeze Warning in effect from 10 PM this evening to 9 AM PST
      Tuesday for zones 38-343-344-383. (See LAXNPWLOX).
     Wind Advisory remains in effect until 4 AM PST Tuesday for
      zones 88-354-355-358-362-369-371-372-374>376-378>380. (See LAXNPWLOX).
     High Wind Warning remains in effect from 4 AM Tuesday to noon
      PST Wednesday for zones
      88-354-355-358-362-369-371-372-374>376-378>380. (See LAXNPWLOX).
     High Surf Advisory in effect until 9 PM PST this evening for
      zones 340-346. (See LAXCFWLOX).
     Frost Advisory in effect from midnight tonight to 9 AM PST
      Tuesday for zones 340-341. (See LAXNPWLOX).
     Freeze Warning in effect from midnight tonight to 9 AM PST
      Tuesday for zones 346>348-357-381-382. (See LAXNPWLOX).
     Wind Advisory remains in effect until noon PST Wednesday for
      zones 370-373-377. (See LAXNPWLOX).
     Red Flag Warning in effect until 6 PM PST Wednesday for zones
      288-354-355-358-362-369>376-378>380-548. (See LAXRFWLOX).
     Red Flag Warning in effect from 10 PM this evening to noon
      PST Wednesday for zones 345-352-353-356-357. (See LAXRFWLOX).
PZ...Gale Warning in effect until 3 PM PST Wednesday for zones
      650-655. (See LAXMWWLOX).
     Small Craft Advisory in effect until 9 PM PST this evening
      for zone 670. (See LAXMWWLOX).
     Small Craft Advisory in effect until 3 AM PST Tuesday for
      zone 673. (See LAXMWWLOX).
     Small Craft Advisory in effect until 3 PM PST Wednesday for
      zone 676. (See LAXMWWLOX).

&&

$$

PUBLIC...MW
AVIATION...Phillips/Lewis
MARINE...DB/Lewis
BEACHES...Lewis
FIRE...Gomberg/Cohen
SYNOPSIS...MW

weather.gov/losangeles

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