434
FXUS66 KLOX 241227
AFDLOX

Area Forecast Discussion
National Weather Service Los Angeles/Oxnard CA
527 AM PDT Fri May 24 2024

.SYNOPSIS...23/901 AM.

Strong onshore flow and a deep marine layer will keep the night
through morning low clouds and fog pattern going with low clouds
reaching the foothills each day. There will be patchy drizzle each
morning. The near shore area will see limited or no clearing through
Saturday. High pressure will bring better clearing and warmer
temperatures to the area starting Sunday and continuing into next
week.

&&

.SHORT TERM (TDY-SUN)...24/422 AM.

Another in a seemingly endless series of days with a very deep
marine layer across the region, now over 5000 feet deep. Low
clouds have pushed all the way into the mountain slopes and into
the far interior valleys of SLO and SBA Counties, and some clouds
could even spill into the Antelope Valley for a few hours this
morning. With the very deep marine layer in place, cyclonic flow
aloft, and some low level lift, there could be some drizzle this
morning, especially in the foothills and mtn slopes south of
Point Conception.

A positively tilted trough extending from the Pac NW into northern
CA will sharpen some as it moves into the forecast area this
afternoon. There may be enough lift and instability within the
deep moist layer to bring a few showers to the mountains this
afternoon and early this evening. With the trough axis remaining
to the west of the region for most of the day, and with very
strong onshore gradients, expect another slow clearing day. Skies
may stay mostly cloudy for much of the day, especially in coastal
and valley areas of L.A./VTU Counties. Strong onshore gradients
will likely produce advisory level winds in the Antelope Valley
and the adjacent foothills, and Wind Advisories are in effect
there for this afternoon and evening. Winds may get close to
advisory levels as well through the Highway 14 Corridor in the
mountains of L.A. County, and advisories may have to be extended
into that area as well. It will be another unseasonably cool day
with highs topping out in the 60s in most coastal and valley areas,
with a few 70-degree readings possible.

N-S gradients will increase across SLO and SBA Counties this
afternoon and evening, and there will be some subsidence once the
trough axis passes that area. Expect gusty NW winds to reach
advisory levels across much of southwestern SBA Counties this
afternoon and evening.

The trough axis will swing through the region this evening and
early tonight, then a broad NW flow pattern aloft will set up
across the area later tonight and Sat. The models show some
reduction in low clouds tonight, which make sense since cooling
aloft will wipe out any weak marine inversion. Expect a rather
less solid and rather haphazard cloud field tonight and Sat
morning, and there should be more in the way of sunshine in most
areas Sat afternoon. Due to increased sunshine and small height
rises, expect a couple of degrees of warming in most areas Sat,
though temps should still be below normal. Strong N-S gradients
will likely produce another round of advisory level winds across
the southwestern coast of SBA County and the western Santa Ynez
mtns late Sat afternoon and evening.

The flow aloft will become more zone Sat night and Sun, and
heights will rise a bit. Expect the marine layer to reorganize,
but it will likely be less deep, with night thru morning low
clouds and fog confined mainly to coastal and valley areas Sat
night/Sun morning. Expect mostly sunny skies in most areas Sunday
afternoon, with a few degrees of warming due to height rises,
warming at 950 mb and slight weakening of the onshore gradients.
High temps will likely rise into the 80s in the Antelope Valley,
and could even approach 80 degrees in the Salinas and Cuyama
Valleys. Temps should rise into the mid to possibly upper 70s in
the warmest valley locations in L.A. and Ventura Counties.

.LONG TERM (MON-THU)...24/526 AM.

Models are in fairly good agreement in showing an upper low
moving toward the coast of southwestern Canada Mon and Tue, then
dropping slowly southeastward thru the Pacific NW Wed and Thu.
Heights across the region gradually rise Mon and Tue, then change
little for Wed and Thu. Onshore gradients remain rather strong
thru the period. Overall, expect rather benign weather Mon
thru Thu, with areas of night/morning low clouds in coastal and
most valley areas. Max temps should rise a bit Mon and Tue, with
little change Wed and Thu, with max temps Tue thru Thu at near
normal levels for the end of May.

&&

.AVIATION...24/0023Z.

At 23Z at KLAX, the marine layer was 3600 ft deep. The top of the
inversion was at 5600 feet with a temperature of 16 C.

High confidence in desert TAFs.

Low to moderate confidence in remainder of TAFs. There is a 30
percent chc that the low clouds could dissipate some time this
late evening or after midnight. There is also a 30 percent chc
that cigs will remain AOA OVC020 at any site.

KLAX...Low to moderate confidence in TAF. There is a 30 percent
of SCT conds developing and persisting into the early morning
hours. Flight Cat changes could be off by +/- 2 hours. High
confidence in any east wind component remaining less than 6 kt.

KBUR...Moderate confidence in TAF. There is a 30 percent
of SCT conds developing later this evening. Flight Cat changes
could be off by +/- 2 hours.

&&

.MARINE...23/933 PM.

Moderate to high confidence in the current forecast. Higher
confidence in wind forecast relative to sea forecast.

Across the outer waters, there is a 80-100 percent chance of
Small Craft Advisory (SCA) level winds through at least late
Friday night, decreasing to 60-80 percent between Saturday and
Sunday. Widespread SCA conditions (winds and seas) are likely
especially between Friday afternoon and Friday night. There is a
moderate chance that winds could drop below SCA levels on
Saturday morning. Winds may drop below SCA levels late Sat
night/Sun morning. There is a 40 percent chance of SCA level
winds on Monday increasing to 60 percent on Tuesday.

Across the nearshore waters along the Central Coast, there is a
30 percent chance of SCA level winds tonight, increasing to 80
percent on Friday afternoon and night, and again on Saturday
afternoon and night. There is a high chance of widespread SCA
conditions (winds and seas) on Friday afternoon and evening. There
is a 30 percent chance of SCA winds during the afternoon and
evening hours Sunday and Monday.

Across the Santa Barbara Channel and into the southern inner
waters, there is a 70-80 percent chance of SCA level winds across
the western and central portions of the Santa Barbara Channel
Friday afternoon and evening, and again Saturday afternoon and
evening. Farther to the south, there is a 30-50 percent chance of
SCA level winds pushing into the southern inner waters Friday
evening and again Saturday evening. Winds and seas should drop
below SCA levels between Sunday and Tuesday.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...Wind Advisory in effect from 2 PM this afternoon to 9 PM PDT
      this evening for zones 349-351-381>383. (See LAXNPWLOX).
PZ...Small Craft Advisory in effect from 9 AM this morning to 3 AM
      PDT Saturday for zone 645. (See LAXMWWLOX).
     Small Craft Advisory in effect from 3 PM this afternoon to 3
      AM PDT Saturday for zone 650. (See LAXMWWLOX).
     Small Craft Advisory in effect until 3 AM PDT Sunday for
      zones 670-673-676. (See LAXMWWLOX).

&&

$$

PUBLIC...DB
AVIATION...Rorke
MARINE...Hall
SYNOPSIS...30

weather.gov/losangeles

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