Pico Rivera, California Weather Forecast Discussion

901
FXUS66 KLOX 232135
AFDLOX
Area Forecast Discussion
National Weather Service Los Angeles/Oxnard CA
235 PM PDT Tue Sep 23 2025
.SYNOPSIS...23/123 PM.
Monsoon moisture will increase tonight resulting in increasing
shower and thunderstorm chances through Wednesday, especially
west of Ventura County. Temperatures will cool off tomorrow
through the rest of the week.
&&
.SHORT TERM (TDY-FRI)...23/206 PM.
A persistent upper low just off the southern California coast
continues to entrain moisture from the south which is resulting in
increasing shower and thunderstorm activity over the coast waters.
However, the upper low has pulled a little to the west and this
has so far kept the mainland convection-free. It`s also steering
the larger area of moisture and instability, near 33n/123w at 2pm,
farther west as well. That was supposed to be the primary weather
maker tonight for the Central Coast so for right now that heavier
activity appears to be maintaining an over water trajectory and
minimal threat to land.
However, there is still moisture entering the area from a more
easterly path and with unstable air in place there is still at
least a 40-60% chance of showers and storms tonight across the
Central Coast. But those showers will be less widespread with less
chances for training and likely lower accumulations overall.
Elsewhere, including Ventura and LA Counties chances for
precipitation are much lower and any rain should be brief with
minimal impacts.
The upper low is expected to move onshore Wed night and Thursday
near Monterey and then drift slowly south back to So Cal Friday.
However, its tap of moisture will cease after Wednesday so at most
there may be a slight chance of showers and thunderstorms over the
mountains during the afternoon. Otherwise, temperatures will be
cooling the rest of the week. By Friday valley and desert highs
will only be in the mid 80s and coastal areas in the 60s and 70s.
.LONG TERM (SAT-TUE)...23/219 PM.
The chances for afternoon mountain and desert convection will
continue into Saturday before finally the upper low`s week plus
vacation over southern California will come to an end as most of
the ensemble solutions are favoring a high pressure ridge
developing for a return of warmer weather. Humidities may remain
on the higher side for the foreseeable future as SST`s locally are
near 70.
&&
.AVIATION...23/2059Z.
At 1833Z at KLAX, there was no marine layer. The top of the sfc-
based inversion was 2600 feet with a temperature of 27 C.
Low to moderate confidence in the current forecast. Higher
confidence in the current forecast for valley and desert
terminals. Lower confidence in the current forecast for coastal
terminals.
There is a 10-20 percent chance of thunderstorms through the
period for all sites, highest for KPRB, KSBP, KSMX, and KSBA.
Tstorm chances for KSBP/KSMX increase to 20-30 percent 02Z-12Z
Wed. -SHRA is possible for all other sites 00Z Wed through the
period. Any tstorm that forms may have gusty and erratic winds,
frequent lightning, and/or small hail.
KLAX...Moderate confidence in TAF. Cigs may remain VFR through the
period. There is a 10 percent chance of thunderstorms through the
period. Any east winds should be less than 7 knots, unless a
thunderstorm were to form.
KBUR...High confidence in forecast. No wind impacts are expected
at this time.
&&
.MARINE...23/150 PM.
Moderate confidence in the current forecast. Local Small Craft
Advisory (SCA) level wind gusts are possible through tonight
across the entire waters, otherwise winds and seas will remain
below SCA levels.
For the water southwest through northwest along the Central
Coast, there is a 30-50 percent chance of SCA level winds on
Wednesday afternoon and evening, increasing to 50-70 percent on
Thursday and Friday afternoon and evening. The highest chances
will be for the waters beyond 30 NM offshore.
Inside the southern California bight, there is a 30-50 percent
chance of SCA levels winds Wednesday and Thursday during the
afternoons and evenings. The highest chances will be for the
western Santa Barbara Channel.
Moisture with a tropical disturbance to the south will bring a
chance of showers and thunderstorms to the coastal waters through
Wednesday night. Low confidence exists in the exact timing and
location of showers and thunderstorms. However, current guidance
suggests more widespread thunderstorm activity will be for the
waters north and west of San Miguel Island tonight. Any thunderstorm
that forms will be capable of producing locally gale force winds
and rough seas, dangerous lightning, heavy rainfall with reduced
visibility, small hail, and waterspouts.
&&
.LOX WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
PZ...NONE.
&&
$$
PUBLIC...MW
AVIATION...Lund
MARINE...Hall/KL
SYNOPSIS...MW
weather.gov/losangeles
Experimental Graphical Hazardous Weather Outlook at:
https://www.weather.gov/erh/ghwo?wfo=lox

NWS LOX Office Area Forecast Discussion