559
FXUS66 KLOX 151222
AFDLOX

Area Forecast Discussion
National Weather Service Los Angeles/Oxnard CA
522 AM PDT Mon Jul 15 2024

.SYNOPSIS...15/236 AM.

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. A cooling
trend will continue through Tuesday, but a warming trend starting
Wednesday will lead to the possibility of extreme heat across the
interior by next weekend.

&&

.SHORT TERM (TDY-WED)...15/259 AM.

The marine layer is 1000 ft deep and although skies were much
clearer than normal late last evening the low clouds have filled
in across most of the coasts except for the SBA south coast. There
are some shower over Riverside county associated with a weak wave
but hi rez short term ensemble guidance shows these showers stay
to the east of LA county. Low clouds will give way to mostly sunny
skies later this morning. There is just enough residual moisture
and instability across the LA/VTA mtns to warrant a slight chc of
TSTMs this afternoon. With the south flow some TSTMs might drift
into the Antelope Vly as well. Max temps will cool some today
except for Southern SBA county where local northerly flow will
bring some warming.

Tuesday will be the coolest day of the next 7 as hgts fall in
response to a trof approaching from the west. The most noticeable
cooling will occur across the interior of SLO county. Max temps
will end up about 4 degrees blo normal across VTA and LA counties
(xcp for the Antelope Vly where max temps will be 3 degrees above
normals) and 4 to 8 degrees blo normal for SLO and SBA counties.

On 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. Onshore flow will persist and there
will be morning low clouds at most of the coastal locations.

.LONG TERM (THU-SUN)...15/334 AM.

Both Deterministic and ensemble solutions agree that the upper
high will strengthen and push to the west. By Saturday it will be
over the southern NV/UT border. Heights will rise to near 596 dam
again. Max temps will rise 1 to 3 degrees each day Wed through
Fri. On Saturday the csts/vlys will cool a couple of degrees as
onshore flow increases. The interior will warm another 1 to 2
degrees.

Lower mtn elevations and the far interior will all have triple
digit heat on Saturday with the Antelope Vly topping out between
105 and 110 degrees. These Antelope Vly temps will likely bring
another round of Excessive Heat Warnings. The rest of the
interior, however, will likely come in just below warning
criteria.

Some cooling is forecast for next Sunday but both the EC and GFS
keep hgts similar to Saturday and would not be surprised if temps
remain similar esp inland.

There is no convection in the fcst but the upper high is in
position that there could be some monsoon flow at some point.

Onshore flow will keep the night through morning low cloud pattern
going through the period. The higher than normal hgts will keep
the marine layer shallow enough to preclude any vly penetration
unless a surprise eddy slins up. Toward the end of the week
onshore flow increases enough that some west facing beaches may
struggle to clear.

&&

.AVIATION...15/1218Z.

At 08Z at KLAX, the marine layer was 1200 feet deep. The top of
the inversion was at 3400 feet with a temperature of 25 deg C.

High confidence in CAVU TAFs for KBUR and KVNY.

There is a 15 percent chance of a TSTM at KPMD and KWJF tomorrow
afternoon 20Z-02Z.

Low clouds were widespread in most coastal areas, and in the
valleys of Ventura County. There is a chance that low clouds
will push into the Salinas Valley, the Santa Ynez Valley, and the
San Gabriel Valley for a few hours this morning. Conds were mostly
IFR to LIFR, except locally VLIFR on the Central Coast and in the
valleys, and low MVFR in coastal sections of L.A. County. Skies
should clear by mid morning in the valleys and late morning
elsewhere, except possibly early afternoon near the coast. Expect
a very similar low cloud pattern tonight.

KLAX...Low confidence in TAF. There is a 30% chance that cigs
will scatter out at times thru 16Z. There is a 20% chance that
cigs will linger until 20Z, but also a 20% chance that cigs will
scatter out as early at 16Z. There is a 20-30% chance that cigs
will not arrive tonight until past 16/08Z. No significant east
wind component is expected.

KBUR...Good confidence in CAVU TAF.

&&

.MARINE...15/504 AM.

In the outer waters, Small Craft Advisory (SCA) conditions are
not expected thru this morning. In the northern zone (PZZ670),
there is a 40% chance of SCA winds this afternoon thru Wed night,
mainly during the afternoon/evening hours. SCA conds are likely
(70% chance) Thu thru Fri night. In the southern two zones
(PZZ673/676), SCA conds are likely (70% chance) this afternoon
thru late tonight, during the afternoon thru late night hours
Tue thru Wed Night, and most of the time Thu thru Fri night.

In the inner waters N of Pt. Sal, there is a 20% chance of SCA
conds in the afternoon/evening hours today, and a 40% chance
during the afternoon/eve hours Tue thru Fri night. Otherwise,
SCA conds are not expected thru Fri night.

In the inner waters S of Pt. Conception, there is a 30-40% chance
of SCA winds across the far western portion of the Santa Barbara
Channel each late afternoon thru the late each night today thru
Fri. Otherwise, SCA conds are not expected thru Fri night.

Areas of dense fog will reduce visibilities to below one mile
this morning. There is a good chance that this will occur during
the night thru morning hours each day thru Wed or Thu.

&&

.BEACHES...15/507 AM.

A series of Southern Hemispheric storms will send a long-period,
S to SW swell (around 18-second wave periods) to the Southern
California coastal waters during early to middle parts of this
week. Wave periods will gradually shorten 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 is likely (over 80% chance)
from Tue thru Thu. The area of greatest concern for these impacts
will be on beaches with highest exposure to a S to SW swell
directions -- especially on the L.A. and VTU County beaches.
These factors warrant the issuance of a Beach Hazards Statement
for the beaches of L.A. and VTU 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 this afternoon to 3
      AM PDT Tuesday for zones 673-676. (See LAXMWWLOX).

&&

$$

PUBLIC...Rorke
AVIATION...DB
MARINE...DB
BEACHES...Cohen/DB
SYNOPSIS...jld

weather.gov/losangeles

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