-- Discussion containing changed information from previous version are highlighted. --
336
FXUS66 KLOX 012309
AFDLOX

Area Forecast Discussion
National Weather Service Los Angeles/Oxnard CA
409 PM PDT Sat Jun 1 2024

.SYNOPSIS...01/128 PM.

A persistent marine layer with cooler than normal weather will
remain in place through the weekend as strong onshore flow
continues across the area. High pressure aloft will build in next
week, weaken onshore flow, and bring a warming trend to area. The
hottest temperatures are expected for the interior portions of
the area Tuesday through Thursday.

&&

.SHORT TERM (TDY-TUE)...01/203 PM.

Southwest California continues to be mired in a deep marine layer
and strong onshore flow pattern as a result of persistent
troughing along the West Coast. While not atypical to have low
clouds in May and June, this year does seem to be a little more
gloomy than usual. The trough is expected to start loosening its
grip Sunday into next week that will bring about a warming trend,
especially by Tuesday, with the main focus being the deserts and
other areas far removed from the still chilly influence of the
Pacific Ocean.

There are already signs of improving conditions as northerly flow
is starting to develop across our western areas, where satellite
imagery is showing low clouds rapidly pulling away from the coast
near Pt Conception. In addition, downslope warming due to the
gusty north winds passing over the western Transverse range is
causing warming and drying conditions there this afternoon. While
clearing may not reach all areas to the east and south, this is a
good sign that better clearing is likely over the next couple days
along with a slight warming trend. Despite these current trends,
clouds are expected to reform in most coast/valley areas overnight
tonight and last through early afternoon Sunday, and likely
longer at some beaches.

High pressure tries to build over the area Monday, however, there
is one more weak trough that will pass through the West Coast,
keeping temperatures on the cooler side still. By Tuesday the
trough will be east of California. With weakening onshore flow and
a warmer air mass in place most areas should experience a warming
trend and much earlier clearing of the marine layer. The one
exception will likely be the immediate coast where onshore flow
and a strengthening inversion may keep low clouds lingering into
the afternoon. Coastal valley highs Tuesday should be close to 90
and even farther inland in the deserts temps should be close to
100.

.LONG TERM (WED-SAT)...01/209 PM.

The warmest day of this stretch will be Wednesday in most areas as
high pressure is at it`s peak locally and onshore gradients are
weakest. Still, due to the cold ocean SST`s and likely a strong
and low marine inversion, coastal areas temps will only rise to
around normal for this time of year. Inland temperatures, though,
will climb into the lower 90s for coast valleys and lower 100s for
the deserts.

A cooling trend will begin in most areas Thursday as high pressure
shifts east and onshore flow strengthens. By next Friday and
especially Saturday highs will again be 2-5 degrees below normal
for coast/valleys with a very likely return of a deepening marine
layer that will keep skies cloudy into the afternoon.

&&

.AVIATION...
-- Changed Discussion --
01/2309Z.

At 2215Z at KLAX, the marine layer was 2600 ft deep. The top of
the inversion was at 4800 feet with a temperature of 20 deg C.

Overall, moderate to high confidence in 00Z TAF package. High
confidence in return of CIG/VSBY restrictions to all coastal and
valley sites, but only moderate confidence in timing of flight
category changes (could be +/- 2 hours of current forecasts).

KLAX...Moderate confidence in 00Z TAF. There is a 40% chance that
IFR conditions will not develop overnight. Moderate confidence in
timing of flight category changes (could be +/- 2 hours of current
forecasts). No significant easterly wind component is expected.

KBUR...Moderate confidence in 00Z TAF. Timing of flight category
changes could be +/- 2 hours of current forecasts.
-- End Changed Discussion --

&&

.MARINE...01/107 PM.

In the northern outer waters zone (PZZ670), SCA winds will likely
to increase to Gale Force (70% chance) this afternoon and
continue thru late tonight. Then, SCA conds are expected (80%
chance) late tonight thru Tue. There is a 40% chance gales Sun
afternoon/eve. There is a 50% chance of SCA conds Tue night/Wed
morning. Conds should then be below SCA levels Wed afternoon
through Thu.

In the southern two outer waters zones, (PZZ673/676), SCA conds
are likely this afternoon (70-80% chance), continuing thru late
Mon night or Tue. Conds should then be below SCA levels late Tue
night through Thu.

In the inner waters N of Pt. Sal, SCA level winds are likely (70%
chance) during the afternoon/eve hours today thru Mon and possible
thru Tue. Conds will then be below SCA levels Tue night through
Thu.

In the inner waters S of Pt. Sal, there is a 60% chance of SCA
winds in western portion of the SBA Channel during the afternoon
and evening hours today through Mon. Otherwise, conds over the
inner waters should be below SCA levels thru Thu.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
-- Changed Discussion --
CA...Wind Advisory remains in effect until 3 AM PDT Sunday for
      zones 349-351. (See LAXNPWLOX).
     Wind Advisory remains in effect until 9 PM PDT this evening
      for zones 381-383. (See LAXNPWLOX).
PZ...Small Craft Advisory in effect until 3 AM PDT Tuesday for
      zones 645-673-676. (See LAXMWWLOX).
     Small Craft Advisory in effect until 3 AM PDT Sunday for zone
      650. (See LAXMWWLOX).
     Gale Warning in effect until 3 AM PDT Sunday for zone 670. (See LAXMWWLOX).
-- End Changed Discussion --

&&

$$

PUBLIC...MW
AVIATION...RAT
MARINE...Sirard
SYNOPSIS...Hall

weather.gov/losangeles

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