066
FXUS66 KLOX 050429
AFDLOX

Area Forecast Discussion...UPDATED
National Weather Service Los Angeles/Oxnard CA
929 PM PDT Sat May 4 2024

.SYNOPSIS...04/928 PM.

A cold storm system is moving over the region, bringing periods
of light rain to the area through tonight. Temperatures will be
much cooler than normal through Sunday, but warmer than the
previous day, and there will be gusty winds at times. Dry and
warmer weather is expected next week.

&&

.SHORT TERM (SAT-TUE)...04/926 PM.

***UPDATE***

High temperatures today were colder than normal by 8 to 12
degrees, with most highs in the 60s. Daytime heating was
tempered by a deep marine layer in the morning, followed by
increasing high clouds and a cooling airmass as the tail end of a
dying front affected the region.

The front produced light rain across San Luis Obispo and Santa
Barbara counties starting late this afternoon. Totals are mostly
under 0.10 inches, with 0.25 - 0.5 inches across mountain and
foothills, and the NW portion of SLO county. The only measured
outlier is Rocky Butte (NW SLO county), that saw 0.91 inches.
Light rain reached Ventura County this evening, and is just
starting to affect portions of LA county. Rainfall totals for
these southern counties are still expected to be light and low
impact, with under 0.10 inches across coasts, valleys, and
deserts. Rain is still expected to subside for all but mountain
areas by tomorrow morning.

Tomorrow skies are expected to be partly cloudy to clear with
little temperatures inversion following the frontal system. This
will allow temperatures to warm somewhat compared to the
previous day for much of SLO and SBA Counties (4 to 8 degrees),
and coasts and valleys of Ventura and Los Angles Counties (2 to 5
degrees).

Forecast is still on track. Winds are currently gusting 40 to 50
mph for LA County mountains and the Antelope Valley. The gusty
winds are expected to expand across the Ventura mountains, and
the Santa Barbara south coast and mountains tonight.

***From Previous Discussion***

Sprinkles/showers are expected to last no longer than 3-4 hours
in any one location. Storms like this that move inland over
northern California and move south along the Sierra spine
typically result in lighter rainfall amounts locally, and
especially from southeast Santa Barbara to western LA County due
to downsloping flow off the Transverse range. There may be a
little reinforcing southwest flow over southeastern LA County that
will generate slightly higher rain rates there and especially in
the eastern San Gabriel Mountains, but amounts there should top
off at around a half inch. Snow levels along the frontal boundary
are way up above 8000 feet so only the highest peaks will see any
frozen precip.

All the precip will be out of the area before the sun rises
Sunday, except for possibly some lingering light showers on the
north facing slopes Sunday morning. Otherwise, clearing skies
expected with plenty of sunshine but temperatures well below
normal.

The storm is generating some gusty westerly winds that will
continue into Sunday, and will be strongest in the mountains and
Antelope Valley.

Dry and warmer weather expected Monday and Tuesday, but with some
gusty northerly winds at times, especially southern Santa Barbara
County and the I5 corridor.

.LONG TERM (WED-SAT)...04/221 PM.

A slow warming trend is expected to continue through next week,
but with some uncertainties later in the week and next weekend as
some model solutions show a weak upper low developing over
northern California. The only expected outcome from this would be
slightly cooler temperatures than currently predicted. Otherwise,
with the exception of daily north winds across the mountains and
southern Santa Barbara County, weather conditions are expected to
low impact with highs near to slightly above normal levels by mid
week.

&&

.AVIATION...05/0223Z.

At 01Z at KLAX, there was no marine layer nor inversion.

Low to moderate confidence in TAFs. Light showers will be
possible across the area through tonight, with VFR conditions
expected after around 14Z. Confidence in timing of flight category
changes will be low, and wind speeds may be off by +/- 5 kts
during peak winds. Wind directions may be variable, especially
during wind shifts and periods of wind below 10 kts.

KLAX...Moderate confidence in TAF. Cigs may bounce between
BKN025-BKN040, and will likely be BKN050 or higher by around
11Z-14Z. No significant easterly wind component is expected.

KBUR...Low confidence in TAF. Cigs may bounce between
BKN015-BKN040, until becoming BKN050 or higher by around 10Z-13Z.
Much uncertainty with regards to wind direction as wind shift from
14Z-19Z.

&&

.MARINE...04/825 PM.

For the Outer Waters, moderate to high confidence in current
forecast. Tonight through Wednesday, high confidence in
combination of Small Craft Advisory (SCA) level winds and seas
(with SCA level seas developing Tuesday/Wednesday). There is a 70%
chance of Gale force winds across zones 673/676 and 30% for zone
670 Sunday afternoon through Sunday night then again Tuesday and
Tuesday night. For Thursday, there is a 40-50% chance of SCA level
winds.

For the Inner Waters north of Point Sal, moderate to high
confidence in current forecast. Tonight through Wednesday, high
confidence in a combination of SCA level winds and seas (with the
SCA level seas developing Tuesday/Wednesday). There is a 30%
chance of Gale force winds Sunday afternoon/evening then again
Tuesday/Wednesday.

For the Inner Waters south of Point Conception, moderate to high
confidence in current forecast. Tonight through Sunday night, high
confidence in SCA level winds (with the strongest winds across
western sections). There is a 60% chance of Gale force winds
Sunday afternoon and Sunday night for western portion of zone 650.
and 30% chance for zone 655. For Monday through Wednesday, there
is a 60-70% chance of SCA level winds across the western half of
the Santa Barbara Channel and a 30% chance of SCA level winds
elsewhere. For Thursday, high confidence in winds and seas
remaining below SCA levels.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...Wind Advisory remains in effect from 10 AM to 9 PM PDT Sunday
      for zones 87-340-341-346>348-354-355-362-366. (See LAXNPWLOX).
     Wind Advisory remains in effect until 3 AM PDT Monday for
      zones 349>353-376>378. (See LAXNPWLOX).
     Wind Advisory remains in effect until 5 AM PDT Sunday for
      zones 379>383. (See LAXNPWLOX).
PZ...Small Craft Advisory in effect until 3 AM PDT Sunday for
      zones 645-670. (See LAXMWWLOX).
     Small Craft Advisory in effect until 3 PM PDT Sunday for
      zones 650-655-673-676. (See LAXMWWLOX).
     Gale Watch in effect from Sunday afternoon through late
      Sunday night for zones 650-655-673-676. (See LAXMWWLOX).

&&

$$

PUBLIC...MW/Schoenfeld
AVIATION...Schoenfeld
MARINE...Gomberg/RAT
SYNOPSIS...MW/Schoenfeld

weather.gov/losangeles

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