680
FXUS66 KLOX 252021
AFDLOX

Area Forecast Discussion
National Weather Service Los Angeles/Oxnard CA
121 PM PDT Tue Jun 25 2024

.SYNOPSIS...25/227 AM.

A gradual cooling trend will continue through midweek as high
pressure weakens over the area and onshore flow strengthens. Night
through morning low clouds and fog will slowly return to the
coastal areas. Temperatures will likely rebound next weekend as
high pressure builds back into the region.

&&

.SHORT TERM (TDY-FRI)...25/117 PM.

The latest satellite imagery showed no significant clouds
building up across the high terrain supports little to no threat
of even isolated showers for those areas and virtually no chance
elsewhere. Drying trends aloft should maintain dry conditions
through the short term minus the small chance for morning drizzle
with a deepening marine layer as early as Thursday.

Modest cooling and moistening trends were evident just about
everywhere, but most significant towards the coast where
moderate onshore trends is a reverse of trends of previous days,
asserting the greater natural cooling effects a recovering marine
layer. Heat products for portions of the interior are set to
expire this evening with no plans for further extension as
cooling trends (especially for morning low temperatures) continue
into midweek.

Weak ridging aloft will be replaced by weak troughing by Friday
with a gradual return to night to morning low clouds and fog that
will venture further inland each day save for possible the Santa
Barbara South Coast due to an increase in Sundowner Activity
beginning Wednesday evening. Breezy northwest to onshore winds are
expected during this time and may approach advisory levels for
areas prone to northwest to onshore winds such as southwest Santa
Barbara County and the mountains near the I-5 corridor into the
western Antelope Valley and foothills. Increased marine layer
presence and earlier and stronger onshore flow will settle daytime
highs Thursday and Friday closer to normals with 70s common near
the coast, 80s to near 90 for coastal valleys and higher terrain,
and 90s further inland.

.LONG TERM (SAT-TUE)...25/117 PM.

We have moderate confidence in the extended period with a warm up
as early as the weekend but more likely (70-80 percent chance)
into early next week due to a building ridge. Low to moderate
heat impacts may return by Sunday with a 30-40 percent chance of
moderate to high heat impacts and the need associated heat
products for at least interior areas by Tuesday of next week. The
ridge may squash the marine layer and associated low clouds back
to the coast with an uptick of northerly flow Sunday potentially
clearing at least south facing coasts. Southwest Santa Barbara
County and the mountains near the I-5 corridor may reach advisory
level northwest winds around the Sunday/Monday time frame, which
could locally enhance warming trends such as for the Santa
Barbara County South Coast including Santa Barbara City.

&&

.AVIATION...25/1636Z.

At 16Z over KLAX, the marine layer was 600 feet deep. The top of
the inversion was 3000 feet and 25 degrees Celsius.

High confidence in VFR conditions with lighter than usual winds.
There is a 5-10% chance of afternoon thunderstorms over the
mountains and over KWJF KPMD. Moderate confidence in more low
cloud coverage over the region tonight into Wednesday, but
generally low confidence in exact coverage and timing. There is a
chance for LIFR ceilings and visibility at KSBP (30%) KSMX (50%)
KSBA (10%). There is a chance for IFR conditions at KOXR (30%)
KCMA (20%) KSMO (40%) KLAX (40%) KLGB (50%). Otherwise, VFR
conditions expected.

KLAX...High confidence in VFR conditions through 04Z. There is a
50% chance of ceilings tonight, forming as early as 06Z or as
late as 12Z. Moderate confidence in IFR conditions if ceilings
form. SE winds are likely 09-15Z, but high confidence in winds
staying under 8 knots.

KBUR...High confidence in VFR conditions through Wednesday with
seasonal winds.

&&

.MARINE...25/846 AM.

Patchy dense fog will cover more of the area tonight and
Wednesday, with a possibility of being dense especially off the
Central Coast.

There is a 20% chance of Small Craft Advisory (SCA) level wind
gusts this tonight in the Outer Waters (offshore waters of the
Central Coast to San Nicolas Island). Otherwise high confidence in
quieter than usual conditions into Wednesday.

Northwest winds will increase Wednesday and Thursday. High
confidence in SCA conditions for the outer waters, with a 20-40%
chance of low-end gale force winds (highest chances well off the
Central Coast). For the nearshore waters, the is a 40-60% chance
of SCA winds along the Central Coast (afternoon and evening hours)
and a 20% chance for the western Santa Barbara Channel. Higher
chances on Thursday.

Winds will gradually weaken Friday and Saturday.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...Heat Advisory remains in effect until 8 PM PDT this evening
      for zones 38-344-345-353. (See LAXNPWLOX).
     Excessive Heat Warning remains in effect until 8 PM PDT this
      evening for zones 382-383. (See LAXNPWLOX).
PZ...NONE.

&&

$$

PUBLIC...Munroe
AVIATION...RK
MARINE...RK
SYNOPSIS...30

weather.gov/losangeles

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