878
FXUS66 KLOX 052034
AFDLOX

Area Forecast Discussion
National Weather Service Los Angeles/Oxnard CA
134 PM PDT Wed Jun 5 2024

.SYNOPSIS...05/226 AM.

High pressure over the region will continue the warming trend
through today, most pronounced away from the coast. The marine
layer will continue to bring some night through morning low clouds
to the coastal and valley areas. well above normal temperatures
will continue across the interior valleys for much of this week.
Closer to the coast, high temperatures will be moderated by the
marine layer and moderate to strong onshore flow.

&&

.SHORT TERM (TDY-SAT)...05/133 PM.

Overall for the short term, 12Z models in good synoptic agreement
through the period. At upper levels, ridge will remain over the
desert Southwest through Thursday then will shift eastward Friday
and Saturday as a trough develops along the West Coast. Near the
surface, onshore flow will gradually strengthen through the
period.

Forecast-wise for the immediate short term, main issue is heat.
With upper ridge remaining dominant feature through Thursday,
inland heat will continue. Looking at both deterministic and
ensemble stuff, heat will continue through Thursday across
interior sections with temperatures actually threatening records
across the Antelope Valley. So will keep EXCESSIVE HEAT WARNING in
effect for the Antelope Valley and HEAT ADVISORIES in effect for
interior San Luis Obispo county, the Cuyama Valley and the western
range of the San Gabriel Mountains. For areas west of the
mountains, a continued marine influence and moderate to strong
onshore gradients will keep things cooler. For Friday and
Saturday, all areas will experience some slight cooling on Friday
and a bit more pronounced cooling on Saturday.

Otherwise, no major issues are expected through Saturday. Will
expect the marine inversion to gradually deepen each day with
better inland penetration each night/morning. Dissipation of
stratus each day should be good for all areas but the immediate
coast where clouds could remain stubborn each afternoon. Also, 12Z
models came in much drier at mid-levels on Thursday, so have
knocked down POPs to below mentionable levels for the mountains.
As for winds, the moderate to strong onshore gradients will
generate gusty southwesterly winds across interior sections,
including the Antelope Valley, but any advisory-level winds should
remain localized.

.LONG TERM (SUN-WED)...05/133 PM.

For the extended, 12Z models continue to exhibit decent synoptic
agreement. At upper levels, trough will linger along the West
Coast through Sunday then will slowly drift southwestward early
next week (well offshore) as a ridge builds once again over the
desert Southwest. Near the surface, moderate to strong onshore
gradients are forecast to continue.

Forecast-wise, no significant issues are anticipated through the
period. Main "concern" will be the continued presence of the
marine layer stratus. Inversion likely to be deepest on Sunday
then will shrink slightly early next week. So, low clouds and fog
will likely push into the coastal valleys each night with good
dissipation each afternoon. Other than the stratus, skies should
remain mostly clear through the middle of next week. As for
temperatures, Sunday will likely be the coolest day with a slight
warming trend for most areas Monday through Wednesday. The onshore
gradients will continue to generate gusty southwesterly winds each
afternoon across interior sections.

&&

.AVIATION...05/1514Z.

At 15Z at KLAX, the marine layer was 1600 ft deep. The top of the
inversion was at 3600 ft with a temperature of 27 Celsius.

IFR/MVFR ceilings and visibility will be common today where/when
clouds exist. Moderate confidence in clearing being slower at
KSBA KOXR KCMA KSMO KLAX KLGB. There is a possibility in 2 hours
or less of clearing at KSBA (30%) KOXR (60%) KCMA (40%). High
confidence in all sites that saw ceilings again today will see
them again tonight into Thursday, with the possible addition of
KPRB (30%). Ceilings and visibility should be improved compared to
today, with 5-8SM and OVC008-015 most common.

KLAX...Ceilings likely to clear today, as early as 17Z and as
late as 20Z. Ceilings will return tonight as early as 02Z and as
late as 06Z. High confidence that any ceilings will be above
OVC010. High confidence in any east winds staying below 8 knots.

KBUR...Ceilings likely to clear today, as early as 16Z and as
late as 18Z. Ceilings will return tonight as early as 06Z and as
late as 10Z. Moderate confidence that ceilings OVC008-012 will be
common, but low confidence on timing of when it will be IFR or
MVFR.

&&

.MARINE...05/1221 PM.

Moderate confidence that local Small Craft Advisory (SCA) winds
and seas will continue through this evening for the offshore
waters off the Central Coast. Otherwise, southeast to southwest
winds will be dominant through Thursday. Winds will peak around 15
knots in the afternoon and in the morning between the islands and
through any channels. There is a 30% chance of SCA level winds
late Sat thru Sun, especially off the Central Coast.

Reduced visibilities are expected each morning through at least
the weekend, possibly dense each morning and below one mile from
Santa Barbara to the Central Coast.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...Heat Advisory remains in effect until 8 PM PDT Thursday for
      zones 38-343-344-379. (See LAXNPWLOX).
     Excessive Heat Warning remains in effect until 8 PM PDT
      Thursday for zones 381>383. (See LAXNPWLOX).
PZ...Small Craft Advisory in effect until 9 PM PDT this evening
      for zone 670. (See LAXMWWLOX).

&&

$$

PUBLIC...Thompson
AVIATION...RK
MARINE...Kittell
SYNOPSIS...30

weather.gov/losangeles

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