281
FXUS66 KLOX 130635
AFDLOX

Area Forecast Discussion...UPDATED
National Weather Service Los Angeles/Oxnard CA
1135 PM PDT Thu Jun 12 2025

.SYNOPSIS...12/804 PM.

High pressure aloft expanding into the Sonoran Desert will build
over the region into Monday. While onshore flow will keep the
coastal sections on the cool side of normal, the air mass will
heat up outside of the marine layer depth through the weekend or
early next week. Gusty northerly winds will develop early next
week across southern Santa Barbara County and through the
Interstate 5 Corridor.

&&

.SHORT TERM (THU-SUN)...12/837 PM.

The latest satellite imagery indicates high pressure aloft over
Baja California this evening and expanding the Sonoran Desert.
This high pressure system will slowly build into the region
through the weekend in a typical late June pattern setup. The air
mass will heat up away from the coast and into the interior
portions of the area, while near the coast and beaches, onshore
flow will keep low clouds and fog hugging the coast. More June
Gloom looks on tap for the next several days at the beaches and
immediate coastal locales. KLAX-KDAG surface pressure gradients
are still progged to weaken slightly each day through Sunday as
500 mb heights climb and 1000-500 mb thickness values increase.
EPS solutions suggest the valley areas to start feeling more of
the heat each day through Sunday which makes sense with onshore
flow weakening some. The valleys will start to pop above normal
starting on Friday or Saturday as less marine influence works its
way into the valleys. EPS max temperature mean climb through the
weekend at KPOC, KBUR, and KIZA. High temperatures for most valley
areas could reach the mid 80s to mid 90s for most valley
locations on Sunday with temperatures reaching or eclipsing the
100 degree mark in the hottest locations.

A weak disturbance over the north Central Pacific Ocean will move
toward the West Coast through Monday and likely brush the area
Monday. While the trough will likely serve to increase onshore
flow along the Central Coast and across the Southland, a dying
cold front north of the area will tighten the northerly pressure
gradient across the state. Early model solutions suggest KSBA-KSMX
surface pressure gradients to tighten to -4 to -5 mb on Sunday
and Monday nights, while EPS ensemble members suggest high
temperature means in the upper 80s for KSBA each day. ECMWF
Extreme Forecast indices suggests the pattern to be stronger than
CFSR period, while NAEFS wind anomalies suggest the coastal winds
along the Central Coast and into southern Santa Barbara County to
be greater than 99th percentile for CFSR period. Concern is
growing for significant Sundowner wind event early next week
bringing hot temperatures and gusty winds to southern Santa
Barbara County.

An update to the forecast will be issued shortly.

***From Previous Discussion***

.LONG TERM (MON-THU)...12/229 PM.

There is some disagreement among the models for the upper level
pattern starting on Monday next week and especially for Tuesday.
Overall the ensembles show many options for the development and
speed of a weak trough of lower pressure that may impact the
region. As a result, confidence in the temperature forecast early
next week and especially on Tuesday is much lower than normal.
There is a chance for a cooler deep marine layer (June Gloom)
pattern, and there is also a chance for another significant warm
spell. By Wednesday, models overall favor broad high pressure to
the south of the region that would allow for temperatures to
trend upwards, especially inland. There is a none-zero chance
some of some heat products being needed somewhere in the
Wednesday to Thursday time period for the warmest desert and
valley areas.

&&

.AVIATION...13/0633Z.

At 0505Z at KLAX, the marine layer was 1700 feet deep, with an
inversion top at 3900 ft and a temperature of 22 C.

High confidence in KPMD and KWJF.

Moderate confidence in TAFs - flight cat changes could be off by
as much as 2 hours and cig hgt by +/- 200 ft.

KLAX...Moderate confidence in TAF. Flight cat changes could be
off by as much as 2 hours and cig hgt by +/- 200 ft. There is a 30
percent chc no no SCT conds in the afternoon. No significant east
wind component is expected.

KBUR...Moderate confidence in TAF. Timing of cig/vsby restriction
arrivals this evening may vary by +/- 2 hours, and cig hgt by +/-
200 ft.

&&

.MARINE...12/810 PM.

Small Craft Advisory (SCA) level northwest winds will persist over
the Outer Waters through at least early next week. A Gale Warning
across all of the outer waters will continue through late tonight,
with a 40-50 percent chance of being reissued for the Friday
afternoon/overnight time frame. There is a 40-60 percent chance
of GALES again across the Outer Waters Sunday night through
Tuesday morning. This will likely be focused more so across the
southern Outer Waters.

For the nearshore waters along the Central Coast, SCA level NW
winds will persist through late tonight, and these winds will
likely continue at times through Monday night.

Nearshore south of Point Conception, there is a 40% chance of SCA
conditions across the western portion of the Santa Barbara
Channel during the afternoon/evening hours, with similar chances
late Saturday afternoon and evening. Chances will then increase
Sunday afternoon through Tuesday, with SCA gusts possibly
spreading to the eastern sections of the SBA Channel by Monday
afternoon.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...Wind Advisory in effect until 9 AM PDT Friday for zones
      376>378. (See LAXNPWLOX).
PZ...Small Craft Advisory in effect until 3 AM PDT Friday for zone
      645. (See LAXMWWLOX).
     Gale Warning in effect until 3 AM PDT Friday for zones
      670-673-676. (See LAXMWWLOX).

&&

$$

PUBLIC...Hall/Schoenfeld
AVIATION...Rorke
MARINE...Ciliberti
SYNOPSIS...Hall

weather.gov/losangeles

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