059
FXUS66 KLOX 150402
AFDLOX

Area Forecast Discussion
National Weather Service Los Angeles/Oxnard CA
902 PM PDT Sun Jul 14 2024

.SYNOPSIS...14/837 PM.

There is a chance of thunderstorms this afternoon over the Los
Angeles and Ventura County mountains, otherwise skies will be
clear except for morning low clouds across the coasts. The
cooling trend will continue through at Tuesday, but extreme heat
is possible across the interior by next weekend.

&&

.SHORT TERM (SUN-WED)...14/836 PM.

More convective activity this afternoon, primarily centered
across eastern Antelope Valley and the adjacent foothills.
Several Special Weather statements were issued for strong
thunderstorms across this area, with the main threats being
strong outflow winds and dangerous cloud to ground lightning.
Today`s storms were a bit wetter than yesterday, as precipitable
water values climbed to between 1.2 and 1.4 inches. Current radar
imagery shows convective activity has ended this evening. For
Monday, there is sill residual monsoonal moisture across the
mountains and deserts, with a slight chance of afternoon
thunderstorms lingering across the eastern San Gabriels, eastern
Antelope Valley, and northern Ventura county mountains. Looking
at model cross sections and precipitable water values, the
mositure levels are trending down a bit for Monday, but there is
still ample instability and surface based CAPE values exceeding
1000 J/kg to support the slight chance of thunderstorms for these
areas. Looking at model soundings, there is still the inverted-V
structure, so main threats would continue to be strong outflow
winds, and dangerous cloud to ground lightning, Rainfall will
likely be fairly minimal with storms, so there will continue to be
the threat of isolated dry lightning strikes for the eastern San
Gabriels, eastern Antelope Valley, and northern Ventura county
mountains.

Current satellite imagery shows some low clouds and fog returning
to portions of the LA/Ventura coast and Central Coast and do
expect it to fill in across most coastal areas overnight, locally
spreading into some of the lower coastal valleys. Many interior
areas saw a few degrees of cooling today, however Antelope Valley
continued to climb over 100 degrees. Little change in temperature
is expected Monday.

*** From previous discussion ***

On Tuesday the onshore flow will have a little stronger push to
the east. It should be the coolest day of the next seven with
afternoon high temperatures approaching seasonal normals. Night through
morning low clouds will again persist across all of the coasts
and may penetrate into the lower valleys. Look for 1 to 3 degrees
of cooling with most areas (except the Antelope Valley) coming in
2-4 degrees below normal.

By Wednesday, model solutions continue to show the upper high
strengthening and pushing to the west. This will push up heights
and kick off a warming trend which will persist into next
weekend, especially for interior areas.

.LONG TERM (THU-SUN)...14/138 PM.

Ensemble solutions show the upper high strengthening and pushing
to the west and establishing along the NV/UT border area Thursday
through Sunday. Heights will push up to near 596 dam again. The
warming trend will be most pronounced in the interior, as during
the last heat event.

By Saturday and Sunday max temps across the Antelope Valley are
forecast to be near 110 degrees again and another round of
excessive heat warnings looks likely. The lower elevation mountain
locations and other interior areas should see highs between and
100 and 105, which would put them just under warning criteria.

&&

.AVIATION...14/2322Z.

At 2330z at KLAX, the marine layer was 1000 feet deep. The top of
the inversion was at 4000 feet with a temperature of 26 deg C.

High confidence in CAVU TAFs for KPRB and KVNY.

Moderate confidence for all other TAFs.

Isolated to scattered thunderstorms continue late this afternoon
across the eastern Antelope Valley. Direct impacts will be
possible (around 20% chance) at KPMD and KWJF until 03Z this
evening--reflected by VCTS mention. The strongest thunderstorms
will be capable of producing variable- direction wind gusts
upwards of 40-50 kt, locally heavy rainfall, frequent lightning,
abundant turbulence, and very small hail. Outside of
small thunderstorm chances, CAVU conditions are expected at KPMD
and KWJF, with west-southwest winds gusting around 25 kt this
afternoon.

For remaining TAFs over the coasts and coastal valleys, MVFR to
LIFR cigs with MVFR to IFR vsbys will return tonight through
Monday morning. The timing of flight category changes may vary
+/- 2-3 hours from current forecasts. There is a 30% chance for
minimum vsbys/cigs to be off by a category.

KLAX...Moderate confidence in TAF. There is a 30% chance for cigs
to become LIFR tonight and Monday morning. No significant east
wind component is expected.

KBUR...Moderate confidence in TAF. There is a 30% chance for MVFR
vsbys and IFR cigs to develop late tonight into early Monday
morning.

&&

.MARINE...14/902 PM.

In the outer waters, Small Craft Advisory (SCA) conditions are
not expected thru tonight. In the northern zone (PZZ670), there
is a 30% chance of SCA winds Mon afternoon thru Wed night, mainly
during the afternoon/evening hours. SCA conds are likely (60%
chance) Thu thru Fri. In the southern two zones (PZZ673/676),
there is a 60% chance of SCA level winds Mon thru Fri, especially
during the afternoon/evening hours.

In the inner waters N of Pt. Sal, there is a 20% chance of SCA
conds in the afternoon/evening hours Mon thru Wed, with a 40-50%
chance Thu afternoon/eve. Otherwise, SCA conds are not expected
thru Fri.

In the inner waters south of Pt. Conception, there is a
20-30% chance of SCA winds across the far western portion of the
Santa Barbara Channel each late afternoon thru the late night
hours Mon thru Fri. Otherwise, SCA conds are not expected.

Patchy dense fog will reduce visibilities to below one mile
during the overnight and morning hours each day through early to
middle parts of this week.

&&

.BEACHES...14/122 PM.

A series of Southern Hemispheric storm systems will send a long-
period, southerly to southwesterly swell (around 18-second wave
periods) to the Southern California coastal waters during early
to middle parts of this week. Wave periods will gradually taper
off to around 15 seconds by late week. In response to these
developments, an extended period of elevated surf -- surf heights
of 4-6 feet -- along with powerful and dangerous rip currents
will be likely (over 80% chance) from Tuesday through Thursday.
The area of greatest concern for these impacts will be those
beaches with highest exposure to southerly to southwesterly swell
directions -- especially the Los Angeles and Ventura County
beaches. These factors warrant the issuance of a Beach Hazards
Statement for the beaches of Los Angeles and Ventura Counties.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...Beach Hazards Statement in effect from Tuesday morning
      through Thursday evening for zones 354-362-366. (See LAXCFWLOX).
PZ...Small Craft Advisory in effect from 3 PM Monday to 3 AM PDT
      Tuesday for zones 673-676. (See LAXMWWLOX).

&&

$$

PUBLIC...Gomberg/jld
AVIATION...Gomberg
MARINE...Gomberg/Cohen
BEACHES...Cohen
SYNOPSIS...jld

weather.gov/losangeles

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