Glassell, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

343
FXUS66 KLOX 292114
AFDLOX

Area Forecast Discussion...UPDATED
National Weather Service Los Angeles/Oxnard CA
214 PM PDT Thu May 29 2025

.SYNOPSIS...29/152 PM.

Dramatic warming is expected today and Friday, with above normal
temperatures into the weekend. Highs Friday will near 100 degrees
across inland valleys and deserts. Expect marine layer clouds and
fog each night and morning. There is a slight chance of showers
or thunderstorms this weekend, mostly for the San Gabriel
Mountains.

&&

.SHORT TERM (TDY-SUN)...29/152 PM.

Synoptically, the area is under an the northern portion of a cut-
off Low which is centered about 750 miles to our south. The Low
will slowly move southward off the Baja Peninsula and then return
north before exiting to our Southeast on Sunday night/Monday
morning. The Low brings PWAT values of around an inch to the CWA,
so showers (including thunderstorms) are possible (10-20%). There
is less confidence in the track of a second cut-off Low that will
follow down California next Monday through Wednesday, but by next
Thursday that feature will become part of a CONUS-spanning upper
level trough.

The cutoff low is now centered around 750 miles to our south over
the coastal waters, and is expected to stall just west of Baja
California through Saturday. Concurrently, a ridge of high
pressure is setting up over the southwestern United States and
should build over the next few days. These two very different
synoptic features will both impact our regional weather into the
weekend. Notably with this pattern, northern areas (such as San
Luis Obispo County) will see higher pressure than southern areas,
where the dampening influence of the nearby low will be greater.

Friday is still forecast to be the warmest day, with temperatures
8 to 16 degrees above normal, and highs in the 90s to just above
100 degrees across the valleys, lower mountains, and deserts. Some
calender day records will be in play Friday, most notably for
Paso Robles where the current daily record is 102. Heat Advisories
were added for some Ventura and Los Angeles County locations as
temperatures will be 10 or more degrees above normal. High pressure
aloft will compress the marine layer, thus clouds will be mostly
confided to the coastal plains on Friday. Dense fog will be
possible in the shallow marine layer, including for the coastal
waters, most likely Friday night into Saturday morning.

The ridge starts to break down and onshore flow will increase on
Saturday, and temperatures are expected to trend downwards.
Ensembles still show a moderate range of outcome for the
temperatures forecast, however 2 to 8 degrees of cooling seems
most likely. The largest drop in temperatures will be north of
Point Conception. By Saturday afternoon, the Low will begin to
shuttle moisture into the region and raise PWAT values to around
an inch. Showers/thunderstorms will be possible (10-20% chance Saturday
afternoon through Sunday night, south of Point Conception. The
greatest chance of precipitation will be during the afternoons for
the San Gabriel Mountains.

Tropical Storm Alvin has formed in the eastern Pacific and should
be nearing the southern tip of Baja by late Saturday as a Tropical
Depression, but models are not picking up on any affect this may
have on the motion of our cutoff Low.

Moisture from the current cutoff low will sustain a 10 to 20
percent chance of showers or thunderstorms through Sunday night,
focused south of Point Conception, where PWATs may exceed 1 inch.
The greatest chance of convection will still be over the San
Gabriel Mountains. Expecting the Low to travel eastward on
Sunday, with the center of circulation over the northern Baja
Peninsula. Expecting 500 mb heights will fall rapidly locally,
and temperatures as well.

.LONG TERM (MON-THU)...29/153 PM.

Another low pressure system is expected to drop down along the
California Coast on Monday, clearing out of the region by
Wednesday. There is little model agreement on the track of this
Low and the more general upper level pattern late Monday onward,
thus overall confidence for mid next week is on the low end. Even
so, temperatures are likely to cool each day through Tuesday, when
most highs will be 5 to 10 degrees below normal and in the mid
60s to mid 70s. By Wednesday, most ensembles favor a gradual
warming trend, that will last through the end of the week.

Areas of gusty winds are possible early next week with this
pattern, but it will depend on the path of the low pressure
system. More wind details will be available as we get closer.
Overnight to morning low clouds and fog will occur at times, but
are favored to become less widespread by mid next week.

There are a few ensemble members that are keeping some
precipitation early next week (Mon-Wed), and depending on the
location and axis of that next system, showers and thunderstorms
may again be possible, but the likelihood has been trending down
with the latest model guidance. Probably less than 10% now.

By Thursday the area will be under a broad area of lower pressure
so marine layer heights may increase for a June Gloom pattern, but
no precipitation is in the forecast.

&&

.AVIATION...29/2111Z.

Around 2100Z, the marine layer was 2800 feet deep at KLAX. The
top of the inversion was around 4000 feet with a temperature of 18
C.

Overall, low to moderate confidence in the 18Z TAF Package.
High confidence for desert and valley terminals and low for
coastal sites. Significant lowering of the marine layer is
expected tonight with IFR conditions along the coast and a 20
percent chance of LIFR conditions. There is also a 30% chance
that conditions remain VFR through 18z Fri.

KLAX...Low confidence in the 18Z TAF. Most likely outcome is IFR
cigs developing after 10z, with clearing by 15-17z. There is a 20%
chance of LIFR conditions and a 30% chance of conditions remaining
VFR through 00z Sat. No significant east wind component expected.

KBUR...High confidence in the 18Z TAF.

&&

.MARINE...29/212 PM.

For the outer waters, moderate to high confidence in current
forecast. Widespread Small Craft Advisory (SCA) conditions with
localized GALE force wind gusts are expected through Thursday
morning. From Thursday afternoon into the late night hours, strong
SCA level sustained winds with GALE force wind gusts will be
common across PZZ670/673. For PZZ676, Gale force wind gusts will
likely be confined to far western portions - thus will let the
morning shift decide on whether or not to upgrade to a GALE
warning due to lack of spatial coverage. Thereafter, SCA conds
are expected to linger through Friday morning.

For the weekend, conditions are expected to remain below SCA
criteria through Saturday, with increasing chances for SCA winds
and seas into early next week. Higher confidence in seas reaching
SCA thresholds.

For the nearshore waters along the Central Coast, there will be a
lull in winds (below SCA) early Thursday morning for portions of
PZZ645, before increasing to strong SCA sustained winds with GALE
force wind gusts during the afternoon and evening hours. Conds
are generally expected to remain below SCA criteria through the
weekend. However, there is a 30% chance of SCA level wind gusts
during the afternoon hours on Friday. Low-to-moderate chance for
SCA winds and seas early next week.

For the Santa Barbara Channel, there is a 10-20% chance of SCA
level wind gusts across far western portions of the channel Thu
afternoon/eve. Moderate-to-high confidence in conds remaining
below SCA levels for the weekend.

For the Inner Waters off the Los Angeles and Orange County coasts,
moderate-to-high confidence in conditions remaining below SCA
levels through Sunday.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...Heat Advisory in effect from 11 AM to 8 PM PDT Friday for
      zones 38-88-343>345-358-372-373. (See LAXNPWLOX).
PZ...Small Craft Advisory in effect until 3 PM PDT this afternoon
      for zones 645-670-673-676. (See LAXMWWLOX).
     Gale Warning in effect until 9 PM PDT this evening for zone
      645. (See LAXMWWLOX).
     Gale Warning in effect until 3 AM PDT Friday for zones
      670-673-676. (See LAXMWWLOX).

&&

$$

PUBLIC...Schoenfeld/jld
AVIATION...MW
MARINE...MW/Black
SYNOPSIS...Schoenfeld

weather.gov/losangeles

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