394
FXUS66 KLOX 201100
AFDLOX

Area Forecast Discussion
National Weather Service Los Angeles/Oxnard CA
400 AM PDT Sat Jul 20 2024

.SYNOPSIS...20/253 AM.

Well above normal temperatures are expected through early next
week, especially across the interior areas, with some cooling
expected closer to the coast as onshore flow increases.
Temperatures across the mountains and far interior areas will be
dangerously high, and heat illness will pose a threat to anyone in
those locations through early next week. Night and morning low
clouds and areas of dense fog will continue near the coast.

&&

.SHORT TERM (TDY-MON)...20/400 AM.

Unsurprisingly, heat will continue to be the main story through
the middle of next week with temperatures well above normal across
the region. A ridge of high pressure will remain over the western
states through the majority of the week, resulting in temperatures
remaining elevated through the week. Rising 500 mb heights will
cause interior areas to have a slight warming trend across the
mountains and far interior areas including the Antelope Valley
through Monday. However, increasing onshore trends and a very
shallow marine layer will result in some cooling across the
coasts and into coastal valleys.

Temperatures across the far interior mountains will range from
100 to 110 degrees each day, with coastal valleys reaching 95 to
103 degrees, and temperatures in the 70s across the beaches. While
being quite warm during the days, the coastal valleys and Santa
Clarita Valleys will being on the cooler side (in the 60s) during
the night, so HeatRisk remains lower for those locations.
Overnight low temperatures for the interior, however, will remain
in the 70s (with the Antelope Valley pushing 80s at times) - these
temps will provide little relief overnight and increase the risk
of heat illness. Therefor, an Excessive Heat Warning remains in
place through much of the week for the interior mountains and far
interior locations, while heat advisories span across the Santa
Monica Mountains, Santa Susanna Mountains, Santa Lucia Mountains,
and the San Luis Obispo County`s portion of the Salinas Valley
through Sunday evening.

Winds each afternoon and evening through Sunday will span the
interior mountains and interior valleys (including the Antelope
Valley and I-5 Corridor), with south to southwest wind gusts of 25
to 40 mph expected. Similar wind gust speeds will be expected for
the southwestern portion of Santa Barbara County, however winds
will be north to northwesterly and strongest tonight.

.LONG TERM (TUE-FRI)...19/156 PM.

No significant changes in temperatures early next week so it will
remain dangerously hot across the far interior, and 4-8 degrees
normal elsewhere. Ensemble based guidance indicates slight warming
may develop Tuesday and Wednesday away from the immediate coast
which may push some areas into heat advisory territory,
particularly across the southern Salinas Valley and warmer parts
of the LA/Ventura Valleys. Then as high pressure begins to weaken
Thursday and Friday highs in all areas are expected to cool with
those trends continuing into next weekend.

Lastly, increasing moisture from the southeast east next Tuesday
and Wednesday may be enough to bring some thunderstorms back to
at least eastern LA County. Otherwise, thunderstorm chances will
be under 10% through the period.

&&

.AVIATION...20/0830Z.

At 0521Z at KLAX, the marine layer was 900 feet deep. The top of
the inversion was at 1700 feet with a temperature of 30 Celsius.

High confidence in TAFs for KPRB, KBUR, KVNY, KWJF, and KPMD.

Low confidence in all coastal sites. Minimum flight cat may vary
one category at any time during the fcst period. Timing of flight
cat changes may be off by +/- 2 hours. There is 40% chance of
VLIFR conditions at KSMX, 30% chance at KSBP, KSBA, KOXR, KCMA,
and a 10% chance at KSMO, and KLAX. MVFR-VFR conditions likely at
most coastal sites by 20Z.

KLAX...Low confidence in TAF. Vis may bounce between 1/4 to 1 SM
through 14Z. Timing of VFR transition may be as late as 20Z. No
significant east wind component expected.

KBUR...High confidence TAF with seasonal winds expected.

&&

.MARINE...20/335 AM.

Patchy dense fog and low visibilities under one mile are expected
to impact the coastal waters through the weekend, and may
continue into next week.

High confidence in northwest winds increasing this weekend, with
Gale Force wind likely for the outer waters this afternoon
through Sunday evening. For the nearshore waters off the Central
Coast waters, there is a 60 percent chance for SCA conditions this
afternoon and evening, and again Sunday.

Across the Santa Barbara Channel, there is moderate-to-high
confidence that SCA winds and seas will occur for the western
portion this afternoon and evening, and again Sunday. There is a
40% chance of SCA conditions overspreading the entire channel
during these times.

Moderate confidence in conditions falling below advisory levels
for all waters by Monday afternoon and remaining below through
Wednesday morning. On Wednesday afternoon, a chance for SCA level
conditions returns for the outer waters.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...Excessive Heat Warning remains in effect until 10 PM PDT
      Wednesday for zones 38-344-345-353-376>383. (See LAXNPWLOX).
     Beach Hazards Statement in effect from this evening through
      late Sunday night for zones 87-354-362-366. (See LAXCFWLOX).
     Heat Advisory remains in effect until 10 PM PDT Sunday for
      zones 342-343-369-370-375. (See LAXNPWLOX).
     Heat Advisory in effect until 9 PM PDT this evening for zones
      373-548. (See LAXNPWLOX).
PZ...Small Craft Advisory in effect from 3 PM this afternoon to 3
      AM PDT Sunday for zones 645-650. (See LAXMWWLOX).
     Small Craft Advisory in effect until 3 PM PDT this afternoon
      for zones 670-673-676. (See LAXMWWLOX).
     Gale Warning in effect from 3 PM this afternoon to 9 PM PDT
      Sunday for zones 670-673-676. (See LAXMWWLOX).

&&

$$

PUBLIC...Lund/MW
AVIATION...Lund
MARINE...Schoenfeld/KL
SYNOPSIS...MW/Smith/KL

weather.gov/losangeles

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