000
FXUS66 KLOX 131312
AFDLOX

Area Forecast Discussion
National Weather Service Los Angeles/Oxnard CA
612 AM PDT Sat Apr 13 2024

.SYNOPSIS...13/330 AM.

Much cooler weather is expected through the weekend as another
late season storm moves into the region. Rain will begin tonight
with showers lasting through Sunday. Snow is expected at higher
elevations. A warming trend will begin Monday with dry weather
next week.

&&

.SHORT TERM (TDY-MON)...13/320 AM.

The leading edge of a cold front is about a hundred miles west of
the Central Coast and is expected to move onshore there by late
morning. Light warm frontal showers are expected to develop ahead
of the cold front from Santa Barbara to LA County, but lower
confidence on when these will begin. Hi res models indicate some
light precip developing as early as 6-8am in SB/Ventura counties
but not until around 11am in LA County. The cold front will
follow during the afternoon and early evening with around 6 hours
of light to moderate rain before exiting LA County by around 9pm
tonight. There is enough cold air aloft along the Central Coast to
warrant a slight chance of thunderstorms there during the late
afternoon and evening.

There will be about 3-6 hours of little to no precip following
the first frontal passage with some clearing skies, mainly during
the overnight hours Saturday night. Then precip is expected to
increase again later Saturday night into Sunday as a secondary
cold front and an even colder upper low moves through the region.
With 500mb temps dropping to -28 to -30c Sunday there will be
chances for thunderstorms just about anywhere across the CWA with
periods of heavy rain at times.

Rain totals still expected to be highest across SLO/SB Counties,
mainly coast and south facing mountains where 1-3 inches of rain
are expected. Across LA/Ventura counties amounts drop off to
around a half to one inch, though locally higher amounts possible
where thunderstorms develop. Snow levels expected to be around
6000 feet Saturday then dropping to around 4000-5000 feet Sunday.
Several inches of snow are possible at higher elevations and 2-5
inches down to around 5000 feet.

The storm is expected to exit Sunday evening with dry and warmer
weather Monday and beyond. Some breezy northerly winds possible
Monday.

.LONG TERM (TUE-FRI)...13/329 AM.

Light offshore flow and plenty of sunshine is expected Tuesday
with a building ridge over the eastern Pacific and temperatures
warming into the 70s to lower 80s. The warming trend is expected
to peak Wednesday and Thursday with highs possibly near 90 in the
warmer valleys. The ridge will weaken later in the week for some
cooling and possibly a return of marine layer stratus but
otherwise dry with near normal temperatures.

&&

.AVIATION...13/1311Z.

At 12Z at KLAX, there was a deep moist layer up to about 7000
feet, but no real marine inversion.

Skies will be mostly cloudy thru the period, except partly cloudy
this morning in the Antelope Valley. There were several different
cloud layers, so cigs will bounce around from time to time today
and tonight. For the most part, conds will deteriorate early this
morning, with increasingly widespread MVFR to IFR cigs, and local
LIFR to VLIFR conds in the foothills/mtns. Rain will overspread
the region this morning, then turn to showers from NW to SE this
afternoon/evening. Conds may improve to low VFR or high MVFR in
coastal/vly areas this evening, but IFR to VLIFR conds are still
likely in the foothills/mtns. Another area of rain will likely
push into SLO/SBA Counties late tonight.

Gusty SE-S winds will diminish by early afternoon in most areas.
In the mtns and Antelope Valley, gusty S-SW winds are likely thru
this evening. There will be areas of LLWS, mdt turbulence and UDDF.

KLAX...Low confidence in TAF. There will likely be frequent
changes in cig heights thru the day. Generally, there will be low
VFR to high MVFR conds early this morning, then MVFR conds this
afternoon/evening with some rain, and occasional IFR conds
possible. Conds should improve to low VFR or high MVFR again this
evening and continue that way thru tonight. Cigs should lower late
tonight/Sun morning as additional rain moves into the area.

The wind forecast is very difficult. There will likely be an east
wind component over 10 kt thru at least 19Z, with a 30% chance of
wind gusts to 25 kt from 100 to 130 degrees. Winds should switch
to south, and eventually to SW after 19Z. There is a 30% chance
of the E wind component of 10 to 15 kt continuing thru 21Z or 22Z.

KBUR...Low confidence in TAF. There will likely be frequent
changes in cig heights thru the day. Generally, there will be low
VFR to high MVFR conds early this morning, then MVFR conds this
afternoon/evening with some rain, and occasional IFR conds
possible. Conds should improve to low VFR or high MVFR again this
evening and continue that way thru tonight. Cigs should lower late
tonight/Sun morning as additional rain moves into the area. There
is a 20-30% chance of SW winds 10-15 kt with BKN025 from 20Z-01Z.

&&

.MARINE...13/541 AM.

Complex forecast this weekend, as conds will be marginally close
to thresholds for Small Craft Advisory (SCA) level winds and seas.

A frontal system will likely bring a period of SCA level SE-S winds
to the entire coastal waters this morning, possibly lingering
until early afternoon in the southern inner waters (PZZ655). A
SCA is in effect for all of the coastal waters this morning.

Winds should turn SW behind the front and remain below SCA levels,
with just a 20-30% chance of SCA level winds this afternoon/eve.

In the northern outer waters zone (PZZ670), seas will likely build
to SCA levels this afternoon and continue thru Sun morning, so
the SCA is in effect thru Sun morning there. There is a 40% chance
that seas will remain above SCA levels there thru Sun night/early
Mon, then SCA level winds are likely Mon afternoon thru Mon night.

In the southern two outer waters zones (PZZ673/676), seas will
likely build to SCA levels late tonight, and continue thru Sun
evening, then winds/seas should be at SCA levels Sun night-Tue.

In the inner waters north of Pt Sal, there is a 30% chance of SCA
level winds and/or seas late tonight thru early Mon, then SCA
level NW winds are likely Mon afternoon/eve.

In the SBA Channel, there is a 30% chance of SCA level W winds
Sun eve/night, mainly in western sections. SCA level W-NW winds
are likely Mon afternoon into Mon night.

In the southern inner waters, there is a 30% chance of SCA level
W winds Sun eve/night, and again Mon eve, mainly western sections.

There is a slight chance of thunderstorms in the northern waters
this afternoon, and across the entire waters tonight/Sun.

&&

.BEACHES...13/549 AM.

A low-end high surf event is expected this weekend with strong rip
current activity. On the Central Coast, surf of 7-11 ft is expected
tonight/Sun, highest on W and NW facing beaches. S of Pt Conception,
surf of 5-8 ft is expected Sun, highest on W facing beaches.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...Wind Advisory in effect until 3 PM PDT this afternoon for
      zones 38-344-345. (See LAXNPWLOX).
     Wind Advisory in effect from 10 AM this morning to 9 PM PDT
      this evening for zones 88-375-383. (See LAXNPWLOX).
     High Surf Advisory in effect from 9 PM this evening to 9 PM
      PDT Sunday for zones 340-346. (See LAXCFWLOX).
     Wind Advisory in effect until noon PDT today for zones
      342-349-351. (See LAXNPWLOX).
     Winter Weather Advisory in effect until 5 PM PDT Sunday for
      zones 353-376-377. (See LAXWSWLOX).
     High Surf Advisory in effect from 9 AM to 9 PM PDT Sunday for
      zones 354-362-366. (See LAXCFWLOX).
     Wind Advisory in effect until 9 PM PDT this evening for zones
      378-381-382. (See LAXNPWLOX).
     Winter Weather Advisory in effect from 11 AM this morning to
      5 PM PDT Sunday for zones 379-380. (See LAXWSWLOX).
PZ...Small Craft Advisory in effect until 9 AM PDT this morning
      for zones 645-650-673-676. (See LAXMWWLOX).
     Small Craft Advisory in effect until noon PDT today for zone
      655. (See LAXMWWLOX).
     Small Craft Advisory in effect until 9 AM PDT Sunday for zone
      670. (See LAXMWWLOX).

&&

$$

PUBLIC...MW
AVIATION...DB
MARINE...DB
BEACHES...DB
SYNOPSIS...Gomberg

weather.gov/losangeles

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