171
FXUS66 KLOX 261801
AFDLOX

Area Forecast Discussion
National Weather Service Los Angeles/Oxnard CA
1101 AM PDT Fri Jul 26 2024

.SYNOPSIS...26/909 AM.

Temperatures will cool today to within a few degrees of normal.
This weekend, highs will be 4 to 8 degrees below normal across
the region, with an increase in morning low clouds and fog for
coasts and valleys. Next week, conditions will gradually trend
warmer each day. Locally gusty winds are expected during the
afternoon and evening for the Santa Barbara southwestern coast
and the Antelope Valley.

&&

.SHORT TERM (TDY-SUN)...26/918 AM.

***UPDATE***

No changes to the forecast this morning. Marine layer is running
700-1000` with some deepening expected this weekend as low
pressure aloft moves into northern California. For today,
temperatures will be cooler as mentioned below and the 24 hour
change map already showing widespread cooling anywhere from 2-6
degrees. Some breezy Sundowner winds expected across the
southwestern portion of Santa Barbara County tonight and again
tomorrow night. Probably below advisory levels. And some
increasing afternoon/evening winds expected across the Antelope
Valley as onshore flow increases.

***From Previous Discussion***

Today the heatwave comes to an end. A low pressure center
traveling eastward across NorCal has weakened and pushed the warm
high pressure system to the south. 500 mb heights will rapidly
fall today and tonight. High temperatures will decrease by around
2 to 6 degrees compared to yesterday (except up to 10 degrees
along the Central Coast and inland San Luis Obispo/Santa Barbara
Counties) and will be within a few degrees of normal regionwide.

Through this weekend, there will be little change in the upper
level pattern. 500 mb heights will be on the low side for the
season. The airmass aloft will cool even further for Saturday,
bringing about another significant drop in temperatures by 4 to 8
degrees. A couple more degrees of cooling is possible for Sunday,
and the whole weekend will see high temperatures around 3 to 7
degrees below normal. Expected upper 60s to low 70s at the
beaches, 80s up to around 90 for interior coastal plains and
coastal valleys, and mid 90s across the Antelope Valley.

Strong onshore flow is expected over the next few days, which
will contribute to the cooling trend, and increase the inland
extend and duration of marine layer stratus. Patchy fog and
drizzle will be possible at times, especially tonight into
tomorrow morning, due to falling heights lifting the marine layer.
A significant north- to- south pressure gradient will favor gusty
Sundowner Winds for the Santa Barbara County Southwest Coast this
afternoon and tonight. A Wind Advisory has been issued starting
late this afternoon through early tomorrow morning. Sundowner
Winds may return tomorrow afternoon and night, but are likely to
be sub- advisory level.

.LONG TERM (MON-THU)...26/447 AM.

Starting Monday, a broad ridge centered over the southern central
states is expected to develop. Good confidence that the ridge will
build through at least mid- next week, with 500 mb heights over
SoCal gradually creeping upwards. In response, high temperatures
will nudge up by a couple of degrees each day. Due to a slow rate
of temperature change, significant heat impacts are unlikely
through at least Wednesday. At this time, there is a chance of
moderate HeatRisk Thursday for inland areas, which may be
hazardous for sensitive populations. Strong-to- moderate onshore
flow will maintain a cooling seabreeze for the coastal plains,
along with overnight/morning low clouds and fog for the coasts and
valleys.

Some model solutions hint at the chance for moisture-rich
southeasterly flow aloft mid next week. However there low
confidence in this occurring. Currently there is a < 10 percent
chance of significant upper level moisture flux, that would
moderate temperatures and yield a chance of showers/thunderstorms.

&&

.AVIATION...26/1801Z.

At 1615Z, the marine layer at KLAX was around 1000 feet deep. The
top of the inversion was around 2900 ft with a temp of 28 C.

For 18Z TAF package, high confidence in valley/desert TAFs, but
low to moderate confidence in coastal TAFs. Moderate confidence in
timing of return of CIG/VSBY restrictions as well as potential
flight categories.

KLAX...Moderate confidence in 18Z TAF. There is a 30% chance of
IFR CIGs 18Z-03Z. For tonight, high confidence in return of
CIG/VSBY restrictions, but low confidence in timing (could be
+/- 4 hours of current 08Z forecast). No significant easterly
wind component is expected.

KBUR...High confidence in 18Z TAF as CAVU conditions are expected
through the period.

&&

.MARINE...26/705 AM.

In the Outer Waters, moderate confidence in the forecast. In the
southern two zones (PZZ673/676), Small Craft Advisory (SCA) level
winds will develop this morning, then continue much of the time
through Sun night. There is a 40-50% chance that SCA conds will
also cont Mon, then SCA conds are likely Mon night thru Tue night.
In the northern zone (PZZ670), SCA level winds are likely (60-70%
chance) this afternoon thru late Sat night, with a 40% chance of
SCA conds Sun thru Mon night. SCA conds are likely Tue/Tue night.

For the Inner Waters north of Pt. Sal, moderate confidence in the
forecast. There SCA level winds are likely (60-70% chance) this
afternoon/eve. SCA conds are likely (60% chance) during the
afternoon/eve hours Sat, with a 40% chance of SCA conds during
the afternoon/eve hours Sun thru Tue.

For the Inner Waters south of Pt. Conception, moderate confidence
in the forecast. In western portions of the Santa Barbara Channel,
SCA level W-NW winds are likely (60-70% chance) during the late
afternoon thru late night hours today and Sat, with a 40-50%
chance Sun afternoon/eve. There is a 30% chance of SCA level winds
from Anacapa Island to near Malibu and across portions of the San
Pedro Channel during the afternoon/eve hour today thru Sat.
Otherwise, SCA conds are not expected.

Patchy dense fog will continue to affect much of the coastal
waters this morning, and possibly again late tonight/Sat
morning.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...Wind Advisory in effect from 3 PM this afternoon to 6 AM PDT
      Saturday for zones 349-351. (See LAXNPWLOX).
PZ...Small Craft Advisory in effect from 3 PM this afternoon to 9
      PM PDT this evening for zone 645. (See LAXMWWLOX).
     Small Craft Advisory in effect from 3 PM this afternoon to 3
      AM PDT Saturday for zone 650. (See LAXMWWLOX).
     Small Craft Advisory in effect until 3 AM PDT Sunday for zone
      670. (See LAXMWWLOX).
     Small Craft Advisory in effect until 3 AM PDT Monday for
      zones 673-676. (See LAXMWWLOX).

&&

$$

PUBLIC...MW/Schoenfeld/DB
AVIATION...RAT
MARINE...DB/RAT
SYNOPSIS...MW/Schoenfeld

weather.gov/losangeles

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