396
FXUS66 KLOX 262100
AFDLOX

Area Forecast Discussion
National Weather Service Los Angeles/Oxnard CA
200 PM PDT Sun May 26 2024

.SYNOPSIS...26/159 PM.

A May gray into June gloom pattern can be expected through next
Sunday. Varying amounts of night and morning low clouds and fog
will affect the coast and valleys, otherwise mostly clear skies
will prevail. Temperatures are forecast to be a few degrees below
normal into early this week then warm to near normal to a few
degrees above normal for mid to late week and into next weekend.

&&

.SHORT TERM (TDY-WED)...26/154 PM.

Low clouds continued to cover much of the coast and vlys S of Pt
Conception early this afternoon, as well as the south SBA County
coast and parts of the SBA County Central Coast. The low clouds
should slowly erode to the coast thru the afternoon, but given the
current satellite trends would not be surprised to see some low
clouds linger into early evening. In addition, Catalina Island
probably will remain mostly cloudy for the most part the rest of
today. Otherwise and elsewhere, mostly sunny skies will prevail.

Temps this afternoon are forecast to turn a few degrees warmer
than yesterday, but still remain 4-8 deg below seasonal norms for
most areas. Afternoon highs for the inland coast, vlys and lower
mtns should reach the 70s to near 80, except lower 80s in the
Antelope Vly. The VTU/L.A. County inland coast and vlys should
wind up on the lower end of that temp range due to the persistent
clouds.

Strong onshore pressure gradients will help to bring gusty NW
winds over SW SBA County thru this afternoon, with gusty W-NW
winds for the Antelope Vly into the foothills and I- 5 Corridor.
Winds are expected to be mostly sub-Advisory thru this afternoon.
Elsewhere, breezy to gusty SW-NW winds can be expected this
afternoon.

A broad WSW flow aloft with H5 heights increasing to about
579-580 dam this afternoon will turn more SW thru Mon with H5
heights rising to 581-582 dam by Mon afternoon. Little change can
be expected thru Mon night then flat upper ridging should move in
with H5 heights expected to be around 583-584 dam by Tue
afternoon. The upper level flow should turn more W to NW Tue night
and Wed, with H5 heights increasing further to near 585 dam by
Wed afternoon.

The marine layer May gray pattern will continue thru Wed across
SW CA. The marine inversion is forecast to lower to around
1500-2000 ft tonight, to about 1200-1500 ft or so Mon night and to
near 1000-1400 ft Tue night. Low clouds and some fog should
affect much of the coast and adjacent vlys tonight into Mon
morning, except for the SBA County S coast into the VTU County
vlys. More widespread low clouds should affect all the coast and
most adjacent vlys Mon night into Tue morning, with about the same
amount of cloud cover for Tue night into Wed morning, altho the
inland penetration could wind up less than is currently forecast.
The low clouds should clear to or off the coast for the most part
each afternoon, with Santa Catalina Island probably having some
low clouds linger thru much of the day. Otherwise and elsewhere,
mostly clear nights and mostly sunny days should prevail.

Sundowner winds at well below Advisory levels should affect the
western portions of the S SBA County coast and mtns each evening
thru Mon, then increase to near Advisory levels for Tue evening.
Otherwise, strong onshore gradients will bring breezy to gusty SW-
NW winds to many areas, strongest afternoon and evening hours.
Winds could approach Advisory levels at times in the Antelope Vly
and foothills.

Temps should remain several degrees below normal thru Tue, except
increasing to a few degrees above normal for the interior areas
including some of the mtns and into the Antelope Vly. By Wed,
temps will turn a little bit warmer with highs near normal to a
few degrees above normal for many areas. Highs for much of the
inland coast, vlys and lower mtns should be in the 70s to lower
80s Mon and Tue and in the mid 70s to mid 80s Wed. The warmest
areas should be in the Antelope vly, with highs in the upper 80s
to around 90 each day.

.LONG TERM (THU-SUN)...26/158 PM.

Not a whole lot of change can be expected in the extended period.
It looks a broad NW flow aloft with H5 heights around 583-584 dam
will prevail Thu. Flat upper level ridging is forecast for Fri
with H5 heights around 584 dam, then weak upper level troffiness
should persist Sat and Sun with H5 heights around 582-584 dam.

Good onshore pressure gradients to the N and E will help to keep
the marine layer pattern over the forecast area Thu thru Sun.
Varying amounts of night and morning low clouds and fog are
expected for the coast and vlys, moving farthest inland Sat and
Sun as the marine inversion deepens. Otherwise, mostly clear skies
can be expected thru the period.

Just minor day-to-day changes in temps are forecast, with
readings ranging from a few degrees below normal to a few degrees
above normal depending on location, but the warmest temps should
be for the interior vlys, lwr mtns and deserts. Afternoon highs
for the inland coast and vlys should be in the 70s to around 80,
except into the 80s for the interior vlys as well as lower mtns,
and generally in the low to mid 90s in the Antelope Vly.

&&

.AVIATION...26/1755Z.

At 1738Z at KLAX, the marine layer was 3000 ft deep. The top of
the inversion was at 5600 feet with a temperature of 15 C.

High confidence in desert TAFs and low confidence in
coastal/valley TAFs. Lower confidence for coastal/valley sites due
to uncertainties in the behavior of the marine layer stratus.
Timing of flight cat changes could be off by +/- 4 hours (greatest
uncertainty after 03Z Mon) and CIGs will range between IFR/MVFR
levels. KBUR and KVNY have a 30% chance of remaining VFR after
21Z. Upon return tonight (after 00Z Mon), there is a 30% chance of
IFR CIGs for sites south of Point Conception, and LIFR conds for
KSBP and KSMX.

KLAX...Low confidence in TAF. Timing of flight cat changes could
be off by +/- 2 hours. There is a 30% chance of BKN008 conds at
times upon return tonight. No significant easterly wind component
is expected.

KBUR...Low confidence in TAF. Timing of flight cat changes could
be off by +/- 4 hours. There is a 40% chance of conds remaining
VFR after 21Z, and a 30% chance of BKN008 cigs at times tonight.

&&

.MARINE...26/149 PM.

Moderate to high confidence in forecast.

Across the outer waters, Small Craft Advisory (SCA) level winds
are expected to drop off late tonight. SCA winds are likely to
redevelop Monday afternoon and then persist much the time through
Thursday. There is a 15-30% chance (highest for the northern
waters) of Gale Force winds Tuesday afternoon and night. Then for
all the outer waters there is a 50-70% chance of gales Wednesday
afternoon through Wednesday night. As for seas, Tuesday seas will
build to SCA levels and becoming steep and choppy through at least
Thursday night.

Across the nearshore waters along the Central Coast, SCA level
winds are expected to last into the evening across the western
portions of the waters. There is a 20-30% chance of SCA winds
again during the afternoon/evening hours on Monday. Tuesday
afternoon through Wednesday night, SCA level winds and seas are
likely (60-70%), with a 20-30% chance of Gale Force winds
Wednesday afternoon/evening. SCA seas may linger as late as
Thursday night.

Across the southern inner waters, there is a 30-40% chance of SCA
level winds across the western portion of the Channel each
afternoon and evening through Tuesday, followed by a 60-70%
chance on Wednesday, with a 20-30% chance of gales. South of the
Channel Islands, winds are expected to remain below SCA levels
through at least Wednesday.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
PZ...Small Craft Advisory in effect until 9 PM PDT this evening
      for zone 645. (See LAXMWWLOX).
     Small Craft Advisory in effect until 3 AM PDT Monday for
      zones 670-673-676. (See LAXMWWLOX).

&&

$$

PUBLIC...Sirard
AVIATION...Schoenfeld
MARINE...Lund/Schoenfeld
SYNOPSIS...Sirard

weather.gov/losangeles

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