South San Jose Hills, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

839
FXUS66 KLOX 250854
AFDLOX

Area Forecast Discussion...UPDATED
National Weather Service Los Angeles/Oxnard CA
154 AM PDT Sun May 25 2025

Updated Marine and Beaches Sections

.SYNOPSIS...24/208 PM.

Marine layer clouds will affect the coast and valleys each night
and morning through next week, otherwise look for mostly clear
skies to prevail. Temperatures will be slightly below normal for
most areas into the early part of next week, then trend warmer
than normal for the second half of the week.

&&

.SHORT TERM (TDY-TUE)...24/825 PM.

***UPDATE***

A deep 4000+ ft marine layer capped by a weak inversion brought
reverse clearing to the area with most vly areas remaining cloudy
through at least mid afternoon. A weak trof moved through the area
today. This trof combined with the deep marine layer and strong
onshore flow to bring 2 to 4 degrees of cooling to the csts and 4
to 8 degrees further inland. These max temps are 4 to 8 locally 10
degrees blo normal. A little pop up ridge will bring 2 to 4
degrees of warming to most areas tomorrow with only the LA/VTA
csts seeing no change.

The evening sounding show that the marine layer has shrunk to
about 1500 ft and the current satellite shows low clouds moving
into the Central Coast and just off the Long Beach coast. The low
clouds will likely arrive a little later than they did last night,
but by Sunday morning all of the coasts and most of the vlys will
be covered by low clouds.

Forecast is in good shape and no updates are planned.

***From Previous Discussion***

Upper level troffiness over the forecast area today will be
replaced by weak upper level ridging on Sun, with H5 heights
increasing to around 581 dam. Another upper level trof will move
into the region by Mon afternoon. The trof will move slowly SE
and develop into a weak upper level low (579-580 dam at H5) over
far SW CA by Tue.

The marine layer pattern is going to persist tonight through Tue
with varying amounts of night and morning low clouds and fog
expected for the coast and vlys, altho the inland extent of the
low clouds should gradually lessen each night. Otherwise, mostly
clear skies can be expected across the region for the most part.

Strong onshore pressure gradients are expected to continue each
day. Areas of gusty onshore winds will continue, especially across
the Antelope Valley and adjacent foothills where gusts may reach
advisory level Sun evening. Gusty NW-N winds across southwestern
Santa Barbara County can be expected each evening, and may reach
Advisory levels Sunday and Monday nights.

Temps are forecast to be several deg below normal for many areas
each day, except a few deg above normal for interior areas and
deserts for Sun and Tue. Max temps for the warmest vlys and lwr
mtns should be in the mid 70s to mid 80s Sun, 70s to around 80 on
Mon, and upper 70s and 80s Tue.

.LONG TERM (WED-SAT)...24/210 PM.

Fairly complex upper level pattern during the extended period, but
this results in only minor differences in and GFS deterministic
and mean ensembles. Weak upper level troffiness should linger over
SW CA on Wed, then a relatively weak upper level low will develop
along or just off the nrn Baja coast on Thu. This upper level low
will meander around the nrn Baja region Fri and Sat. At the same
time, upper level ridging will develop and linger over nrn CA.

The proximity of the upper level low will help to keep the marine
layer pattern and onshore pressure gradients over the forecast
area during the extended period. The marine inversion should be
deepest Tue night into Wed morning with plenty of low clouds from
the coast to vlys, including the Santa Clarita Vly. The marine
layer depth should lower gradually Thu thru Sat, with just mainly
coastal areas expected to have the low clouds Fri night/Sat
morning. Otherwise and elsewhere, mostly clear skies will prevail
across the region Wed thru Sat.

A typical diurnal wind pattern can be expected during the extended
period with weak flow at night and breezy to gusty S to W onshore
flow each afternoon and early evening.

Temps on Wed are expected to be from a few deg below normal to
near normal for the coast and vlys and from near normal to a few
deg above normal for inland areas. It will then turn warmer to
several deg above normal for the most part Thu thru Sat. Fri
looks to be the warmest day during the extended period with highs
in the warmest inland areas reaching the mid 80s to mid 90s.

&&

.AVIATION...25/0740Z.

At 0649Z at KLAX, the marine layer was 3600 feet deep. The top of
the inversion was around 4700 feet with a temperature of 15 C.

High confidence in TAFs for KPMD and KWJF.

Low confidence in TAF for KSBA with a 40 percent chc of no low
clouds. If low clouds do arrive they could arrive as early as 10Z
or as late as 15Z.

Moderate confidence in TAFs for KPRB, KSBP, and KSMX. Flight Cat
changes could be off by +/- 90 min and cigs off by +/- 200 ft.

Moderate confidence in the rest of the TAFs. Flight cat changes
could be off by +/- 2 hours and cigs could be up to 500 ft lower
than fcst at times.

KLAX...Moderate confidence in TAF. BKN025 conds may arrive as
early as 08Z and as late as 10Z Sun. There is a 20 percent chc of
SCT conds arriving at 19Z and a 25 percent chc of being delayed
to 22Z. There is a 40 percent chc of BKN015 conds overnight. Good
confidence that any east wind component will be under 7 kt. Low
confidence in the return of cigs after 03Z Mon.

KBUR...Moderate confidence in TAF. Arrival of cigs tonight may be
off +/- 2 hours. There is a 20 percent chc of BKN008 conds
11Z-16Z

&&

.MARINE...25/153 AM.

For the Outer Waters, high confidence in Small Craft Advisory
(SCA) level winds through Memorial Day weekend and into early
Tuesday, with brief lulls possible each morning. Local gusts to 35
kts may occur this afternoon and evening in the northeastern Outer
Waters as well as around Point Conception south to San Nicolas
Island. Seas are expected to remain below SCA criteria through
mid- week, however, there could be localized SCA level seas at
times, with highest chances Monday evening into Tuesday.
Thereafter, moderate chances for SCA winds through Friday, and
seas may build to SCA levels by Thursday.

For the Inner Waters along the Central Coast, moderate confidence
in SCA winds each afternoon and evening through Memorial Day
Weekend (60-80% chance). Local gusts to 35 kt may occur this
afternoon and evening. Seas are expected to remain below SCA
levels through at least mid-week.

For the Santa Barbara Channel, there is a 40-60% chance of SCA
level winds across the western and southern portions of the
Channel, including the waters around the Channel Islands, each
afternoon and evening over the remainder of Memorial Day Weekend.
Lower chances exist Tuesday.

For the Inner Waters off the Los Angeles and Orange County coasts,
high confidence in conditions remaining below advisory levels
this weekend. Local gusts up to 20 kt may occur in the afternoon
through evenings Monday near Malibu and in the far western
portion of the zone. Thereafter, winds and seas are expected to
remain below SCA levels through at least mid-week.

&&

.BEACHES...25/102 AM.

A long period south swell will bring elevated surf conditions up
to 6 feet along with a high risk for hazardous rip currents for
south facing beaches through the remainder of Memorial Day
Weekend.

Considering the expected high beach attendance this weekend,
ocean rescues may be numerous. If you plan on swimming in the
ocean, be sure to swim near an occupied lifeguard tower.

Minor nuisance flooding may occur at susceptible beaches during
high tide in the evening to late night hours Sunday through
Tuesday.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...Beach Hazards Statement in effect through late Monday night
      for zones 354-362-366. (See LAXCFWLOX).
PZ...Small Craft Advisory in effect until 3 AM PDT early this
      morning for zones 645-650. (See LAXMWWLOX).
     Small Craft Advisory in effect from noon today to 9 PM PDT
      this evening for zone 645. (See LAXMWWLOX).
     Small Craft Advisory in effect from 3 PM this afternoon to 9
      PM PDT this evening for zone 650. (See LAXMWWLOX).
     Small Craft Advisory in effect until 3 AM PDT Tuesday for
      zones 670-673-676. (See LAXMWWLOX).

&&

$$

PUBLIC...Sirard/Rorke
AVIATION...Rorke/Schoenfeld
MARINE...Lewis/Gomberg
BEACHES...Lewis
SYNOPSIS...Sirard

weather.gov/losangeles

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