404
FXUS66 KLOX 261608
AFDLOX

Area Forecast Discussion...UPDATED
National Weather Service Los Angeles/Oxnard CA
908 AM PDT Fri Apr 26 2024

.SYNOPSIS...26/314 AM.

Strong onshore flow will create windy conditions across most of
the area today and tonight. Temperatures will be cooler than
normal across Southwest California through today. Look for some
showers on the north mountain slopes through Saturday morning,
otherwise dry weather can be expected along with gradually warmer
temperatures this weekend into the middle of next week.

&&

.SHORT TERM (TDY-SUN)...26/339 AM.

An inside slider is slowly making its way down the CA/NV coast
today and will exit into AZ this evening. This will be the weather
maker for today and this evening.

Currently there is a 5000 ft deep moist layer with no capping
inversion this has allowed for a very haphazard cloud pattern to
develop. North flow has kept most of the csts/vlys south of Pt
Conception clear although there are a grip of clouds across SE LA
county. Western SBA county is also full of clouds due to west
flow. The developing north flow has brought cloudy skies to all of
the north slopes along with a slight chc of showers that will
persist through the day. It will be another cool day despite some
warming across SLO and SBA county with max temps 6 to 12 degrees
blo normals.

Winds will be the biggest concern today. West to northwest winds
will increase through the day as the inside slider brings
increasing north flow aloft and offshore N to S pressure grads at
the sfc. A little cool air advection will force some of the
stronger winds aloft down to the sfc as well. Warning level gusts
from 60 to 65 mph will develop through the I-5 corridor and the
later across the western foothills and Antelope Vly. These strong
winds will bring clouds of blowing dust across the Antelope Vly
which will bring visibilities down to a mile or less. Strong
advisory level winds will affect most of the rest of the mtns.
Very strong winds will develop across the inner waters and these
winds will come ashore with advisory level gusts of 35 to 40 mph.
Please refer to the product LAXNPWLOX for all of the details.

The strongest winds will occur this evening over the mtns as the
inside slider moves into AZ and the best upper level support
develops. The strong winds will prevent any coastal clouds. The
north winds will continue to bring plenty of upslope clouds to the
north slopes as well as a chc of showers. An inch or 2 of snow is
possible over 6000 ft. Gradients and upper level support will
slowly fade starting late in the evening and winds will diminish
after midnight.

Saturday will be a nice if somewhat breezy day. A ridge will move
into the state and hgts will rise to about 572 dam. These hgt
rises along with continued offshore flow form the north and cloud
free skies will result in 3 to 6 degrees of warming across the
area.

Weak ridging and 574 dam hgts will make for a very pleasant
weather day on Sunday. The winds will be greatly diminished and
most areas will see 1 to 3 degrees of warming. Most cst/vly max
temps will end up in the mid 60s to mid 70s.

.LONG TERM (MON-THU)...26/347 AM.

The EC and GFS deterministic and mean ensembles are in generally
good agreement during the extended period. Weak cyclonic flow will
be over the state on Mon and Tue there will be an increase in
cyclonic flow on Wed and Thu.

Onshore flow will slowly increase through the period and will end
up being fairly strong towards the end of next week. There may be
a slight return of low clouds Mon and Tue but more extensive low
clouds are likely in the latter half of next week.

Despite the cyclonic flow hgts are fcst to rise Monday and Tue
and this should allow for two more day of warming. Tuesday should
be the warmest day of the next 7 with most max temps 2 to 4
degrees above normal (the beaches might be below normal). The
increased onshore flow slightly lower hgts and increased marine
layer will bring a cooling trend for Wed and Thu.

&&

.AVIATION...26/1606Z.

At 12Z at KLAX, there was a deep moist layer to around 6500 ft,
but there was no real marine inversion.

Skies were mostly cloudy across the region, except for the
Antelope Valley and some coastal areas. The combination of the
elimination of the inversion and developing NW flow was causing
clouds to begin to break up. However, for this morning, conditions
were highly variable. For the most part, cigs were mostly low VFR
to high MVFR, except IFR to VLIFR in the foothills/mtns. There were
even local IFR cigs in the valleys. Skies should become partly cloudy
in most areas by late morning. Expect much less in the way of clouds
tonight, with most areas remaining VFR. The exception may be on north
facing slopes and in interior SLO/SBA Counties, where IFR to VLIFR
conds are possible. Widespread gusty NW winds will affect the mtns
and much of SLO/SBA Counties, with gusty W-NW winds in coastal and
some valley sections of L.A./VTU Counties and the Antelope Valley.
There will likely be some LLWS and turbulence, with mdt UDDF.

KLAX...Moderate to high confidence in TAF. There is a 20-30%
chance that MVFR cigs will persist thru 17Z or 18Z. There is a 20%
chance of MVFR cigs between 09Z and 16Z Sat. Strong and gusty
west winds are expected later this morning through tonight. There
is a 20% chance that west winds could gust to 30 kt as early as
19Z, and there is a 20% chance that west winds could gusts to 40
kt from 20Z-01Z. There is a 20% chance of northerly cross winds of
12 to 16 kt from 11Z-16Z Sat.

KBUR...Moderate to high confidence in TAF for cigs and vis, but
low confidence in winds. There is a 20-30% chance that MVFR cigs
will persist thru 17Z or 18Z. There is a 20% chance of MVFR cigs
after 09Z tonight.

Winds will be very tricky and may vary quite a bit today. There is
a 20-30% chance of from from 220 to 250 at 12-15 kt with gusts to
20 kt from 18Z thru 23Z.

&&

.MARINE...26/905 AM.

In the Outer Waters, gale force NW winds are expected to become
widespread this morning, then continue thru late Sat night.
However, winds will likely decrease to Small Craft Advisory (SCA)
levels late tonight in the northern zone (PZZ670). There is a
40-50% chance of gales in the northern zone (PZZ670) again Sat
afternoon into Sat night. SCA level winds and seas are expected
Sun thru Tue. There is a 30-40% chance of gale force winds Sun
afternoon/eve, and a 20-30% chance of gale force winds Mon
afternoon/eve, with the lowest threat in the northern zone.

In the Inner Waters N of Pt. Sal, winds will increase to SCA levels
this morning, then to gale force this afternoon. Winds will drop
to SCA levels late tonight. SCA level winds/seas are expected Sun
thru Mon night, with a 40% chance Tue. There is a 25% chance of
gales during the afternoon/eve Sun and Mon.

In the Inner Waters S Pt Conception, winds will increase to SCA
levels rapidly this morning. Winds will increase to gales across
the SBA channel late this morning, and gales will overspread the
channel and the southern inner waters this afternoon. Gales will
likely continue thru late tonight, then decrease to SCA conds.
SCA level wind and seas are likely to continue through late Sun
night, (or Mon night in the western SBA Channel), with the
strongest winds during the late afternoon thru late evening hours.
There is a 50% chance of gales across the western portions of the
SBA Channel late Sat afternoon into late Sat night, with a 30%
chance elsewhere during that time.

Widespread strong to gale force winds will create dangerous sea
conditions across the coastal waters thru the weekend, with
short-period, steep, and choppy waves. There may be dangerous
breaking waves near west-facing harbors. Mariners should remain in
safe harbor until conditions improve.

&&

.BEACHES...26/617 AM.

Moderate W swell and large wind waves are expected to produce low
end High Surf Advisories on west-facing beaches of L.A//VTU Counties
and Catalina Island, and on W and NW facing beaches on the Central
Coast from early this afternoon thru Sat morning. Surf is expected
to reach 4-7 ft with local sets to 8 ft in L.A./VTU Counties, and
7-10 ft with local sets to 12 ft on the Central Coast. Confidence
in high surf is moderate at best. Surf will be choppy and rough.
There is a high risk of rip currents on all beaches thru Sun.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...High Surf Advisory in effect from 2 PM this afternoon to 10
      AM PDT Saturday for zones 87-340-346-354-362-366. (See LAXCFWLOX).
     Wind Advisory in effect until 3 AM PDT Saturday for zones
      88-352-375. (See LAXNPWLOX).
     Wind Advisory remains in effect until 9 PM PDT this evening
      for zones 340>342-346>348-350-354-355-362-366>368. (See LAXNPWLOX).
     Wind Advisory remains in effect until 3 AM PDT Sunday for
      zones 349-351. (See LAXNPWLOX).
     Wind Advisory remains in effect until 3 AM PDT Saturday for
      zones 353-376-377-379-380. (See LAXNPWLOX).
     High Wind Warning remains in effect until 3 AM PDT Saturday
      for zones 378-381-383. (See LAXNPWLOX).
     Wind Advisory remains in effect until noon PDT today for zone
      383. (See LAXNPWLOX).
PZ...Small Craft Advisory in effect until 3 PM PDT this afternoon
      for zones 645-655-670. (See LAXMWWLOX).
     Gale Warning in effect from 3 PM this afternoon to 3 AM PDT
      Saturday for zones 645-655-670. (See LAXMWWLOX).
     Gale Warning in effect until 3 AM PDT Saturday for zone 650. (See LAXMWWLOX).
     Gale Warning in effect until 3 AM PDT Sunday for zones
      673-676. (See LAXMWWLOX).

&&

$$

PUBLIC...Rorke
AVIATION...DB
MARINE...DB/Schoenfeld
BEACHES...DB
SYNOPSIS...Sirard

weather.gov/losangeles

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