Piru, California Weather Forecast Discussion

864
FXUS66 KLOX 070534
AFDLOX
Area Forecast Discussion...UPDATED
National Weather Service Los Angeles/Oxnard CA
1034 PM PDT Sat Sep 6 2025
.SYNOPSIS...06/828 PM.
Near to slightly above normal temperatures will continue through
the weekend, with minor warming on Sunday for most areas. Much
cooler weather is expected next week as a low pressure system
approaches California.
&&
.SHORT TERM (SAT-TUE)...06/845 PM.
***UPDATE***
Temperatures today were about as expected, though the clouds
cleared out well past the local coastal waters today. Current
satellite imagery shows most of the area free from clouds, save
for a few patches trying to form around Catalina Island and Palos
Verdes. Either the marine layer clouds will push in very late
overnight/near dawn, or many people will wake up to clear skies
and the potential for their high temperatures to be ever so
slightly warmer than currently forecast. Overall, not too
impactful, however.
High temperatures tomorrow will warm a few degrees compared to
today, especially as the 500 dam heights rise by 1-2 mb, but the
same general story remains: interior areas/warmest valleys will be
in the low to high 90s, with with areas inland from the coasts in
the 80s to low 90s, and beaches in the high 60s to high 70s.
Other than adjusting the onset time for clouds at a few
locations, no changes were needed to the forecast this evening.
***From Previous Discussion***
Not much day-to-day changes in the forecast through Sunday. An
upper level low pressure system over the Pacific NE will pivot
towards the coast of northern California, pulling warmer air from
the south and causing an upper level ridge of high pressure to
continue to build over southeastern California/four corners area
through Sunday night. As a result, 500 dam heights will increase
by 1-2 mb on Sunday (compared to today), with many areas seeing
1-3 degrees of warming - bringing temperatures 2-5 degrees above
normal for this time of year.
As for sky coverage, night through morning marine layer low clouds
and patchy fog will continue for most coastal areas, while along
the Central Coast the marine layer will be a little deeper and
push into some of the valleys Sunday morning, including the
Salinas Valley.
By Monday, the upper low will be moving inland near the CA/OR
border and this will be the start of a significant cooling trend
that will continue through next week. The marine layer will deepen
each day and easily push into the LA/Ventura valleys each
morning. The trough will initiate a return of northerly flow
across the western portion of the forecast area, in particular the
western Santa Ynez Range, where low end advisory level winds are
possible - especially Monday night when gusts up to 50 mph near
Gaviota will be possible.
.LONG TERM (WED-SAT)...06/303 PM.
The incoming low pressure system will stall and hang out over
northwestern U.S. (Northern CA, OR, WA, NV, ID location), moving
very little through Friday morning. As the affiliated trough
shifts over SW California, 500 mb heights will continue to lower,
with heights falling below 580 dam (the first time since mid to
late June). These lowering heights will support a deepening
marine layer, and the combination of the two will help keep the
cooling trend continuing through most of next week.
The forecast leans more conservatively in terms of the Marine
Layer, with depths of 2000 to 3000 feet forecasted for much of the
week, meaning low clouds could push into the Santa Clarita Valley
and up some of the coastal mountain slopes. With the rapid
deepening of the marine layer, the region could see some morning
drizzle by Tuesday, especially near the lower mountain slopes.
Wednesday and Thursday are expected to be the coolest days with
many valley areas not even getting to 80 degrees and some coastal
areas remaining cloudy much of the day.
Thereafter, most of the ensemble solutions show a warming trend,
but there is quite a bit of disagreement with how quickly
temperatures will rebound. In fact, the more recent solutions are
only showing a brief warm up through Saturday before another
unseasonably cold upper low arrives along the northern California
coast later next weekend. Although it`s very far out, some of the
ECWMF ensembles do suggest some light rain accumulating over the
weekend, but most members show under 0.10 inches, if anything at
all.
&&
.AVIATION...07/0534Z.
At 0429Z at KLAX, the marine layer was 400 feet deep. The top of
the inversion was near 2100 feet with a temperature of 28 C.
High confidence in VFR TAFs for desert airfields (KPMD & KWJF).
Moderate confidence in remaining TAFs. There is a 30% chance of no
CIGs from 10Z to 16Z Sun at KPRB. There is a 20% chc of IFR CIGs
at KVNY and KBUR both from 10Z to 16Z Sun. There is a 20-30% chc of no
cigs at sites south of Point Conception through the period.
Otherwise, timing of CIG/VSBY restrictions for all sites may be
off +/- 2 hours, and flight minimums may be off by one category.
KLAX...Moderate confidence in TAF. Arrival and departure of CIGs
may be off by 2 hours, and flight categories could be off by one
cat when CIGs are present. There is a 20-30% chance the site
remains VFR through the period. High confidence in any east wind
component remaining below 7 kts.
KBUR...Good confidence in TAF. There is a 10-20% chance of IFR
CIGs between 10Z and 15Z.
&&
.MARINE...06/821 PM.
Localized Small Craft Advisory (SCA) level wind gusts are
possible (30% chance) across the waters north of Point Conception
during the afternoon & evening hours through the weekend.
Widespread SCA level winds are expected during the afternoon &
evening hours south of Point Conception through the weekend. Wind
gusts may drop below SCA levels from Point Conception to buoy
46069 Sunday morning.
This coming week, high confidence in SCA level winds during the
afternoon & evening hours south of Point Conception, with a 20-30%
chance of GALE force wind gusts Monday through Wednesday.
Marginal SCA level wind gusts will be possible north of Point
Conception through Wednesday, with increasing chances through the
end of the work week. Seas are likely to remain at or below 8 feet
through Friday.
Inside the southern California bight, there is a moderate chance
of SCA level wind gusts for western/southern portions of the
Santa Barbara Channel, near Point Dume, & across the San Pedro
Channel during the afternoon & evening hours through Sunday.
Winds are expected to become stronger and more widespread across
the inner waters, potentially impacting the eastern portion of the
SBA Channel and the Santa Monica Bay through at least Wednesday.
Seas may exceed 5 feet across western/southern portions of the
SBA Channel on Monday & Tuesday.
&&
.LOX WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
PZ...Small Craft Advisory in effect until 3 AM PDT Tuesday for
      zones 673-676. (See LAXMWWLOX).
&&
$$
PUBLIC...MW/Lund
AVIATION...Ciliberti/Lund
MARINE...Black/Ciliberti
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