Crystal Lake Recreation Area, California Weather Forecast Discussion

547
FXUS66 KLOX 261527
AFDLOX
Area Forecast Discussion...UPDATED
National Weather Service Los Angeles/Oxnard CA
827 AM PDT Fri Sep 26 2025
.SYNOPSIS...26/211 AM.
A weak low pressure system will slowly move through southern
California through Saturday, bringing occasionally isolated
showers and thunderstorms, locally gusty winds, coastal drizzle,
and cooler than normal conditions. A large trough will move
through the west coast early next week maintaining cooler than
normal conditions through Tuesday and bringing light rain to
northern areas. Warming and drying expected to follow through the
end of next week.
&&
.SHORT TERM (TDY-SUN)...26/827 AM.
***UPDATE***
The forecast is well on-track, and no changes have been made to
the ongoing forecast.
***From Previous Discussion***
An upper level low pressure system, mostly cutoff from the
prevailing jet stream, is currently centered over Barstow, and
will continue to move towards the southeast through Saturday. This
low will create a rather complex weather scenario for the next 48
hours - with all sorts of potential weather on the table
including a rapidly deepening marine layer, drizzle, gusty winds,
showers, and thunderstorms.
With the core of the low just to our east, healthy north flow
aloft is generating some gusty winds through the I-5 Corridor
(gusts at Sandberg KSDB just jumped up to 56 mph while Gaviota is
holding at 45 mph). Not expecting these winds to last long as the
low marches towards the southeast, which will weaken and shift the
winds aloft to northeasterly for the rest of Friday and Saturday.
A Wind Advisory is in place for southwest Santa Barbara County
which should be good to expire early this morning. We may need a
short-lived Advisory for the I-5 Corridor if those Sandberg winds
persist. Otherwise, not expecting any additional Wind Advisories
through the week.
While offshore flow is usually dry, this round is not. The same
tropical moisture that brought over 2000 lightning strikes to the
area earlier this week, is swirling around this low (precipitable
water-pwat values will hover around 1.5 inches through the
weekend). The combination of this moisture and the destabilizing
effects of the low will bring periods of isolated to scattered
showers and or thunderstorms over the region. While any area could
see something, the highest chances are over the mountains and
interior valleys (due to the offshore flow) and over Los Angeles
and Ventura Counties. Coastal and valley areas are included as
anything that forms over the interior areas will be moving towards
the ocean with that offshore flow aloft. Saturday remains the day
with the best overall chance when the best moisture (pwats 1.6
inches) and instability (lifted indices -3 to -4 over a large
area) lines up. Upped the chances of rain and thunderstorms over
what the NBM is predicting, as the the ensemble guidance shows
significantly higher chances. While the vast majority of the area
will see minimal impacts with rainfall under 0.10 inches, there
will likely be an isolated cell or two (or three) that produces
some localized impactful downburst winds (up to 50 mph) or brief
heavy rain. The latest high resolution model guidance has pockets
of hourly rain rates of 0.50-0.75 inches per hour, mainly focused
over the Ventura and Los Angeles County Mountains. This means that
there is a low but present threat of flash flooding and burn scar
debris flows if the heaviest cell forms over a vulnerable area.
On the coastal side of the ranges, the low pressure system and
strengthening coastal eddy will continue to deepen the marine
layer each day through Saturday or Sunday. Areas of drizzle are
looking more and more likely - with some wet roads expected.
Hilly areas could see light accumulations.
With cooler air mass associated with the low, and the ample
clouds, temperatures will remain much below normal (by 6 to 12
degrees).
.LONG TERM (MON-THU)...26/314 AM.
A cold low pressure system currently brewing over Alaska, is
expected to drop into British Columbia early next week and spawn a
deep trough off the west coast. This trough will form a vigorous
cold front or two that will sweep down the Washington and Oregon
Coast Sunday through Monday, and through California later Monday
through Wednesday. These fronts will weaken significantly by the
time they reach the southern half of California - with very little
left over for us. There is a 10-40% chance of any measurable
rain, with the higher chances over the Central Coast. Any
accumulations should be light and generally under 0.25 inches.
There will likely be some gusty west winds Tuesday or Wednesday
after the front moves through.
Temperatures will remain well below normal through Tuesday or
Wednesday, but will steadily warm up after as high pressure aloft
builds in.
&&
.AVIATION...26/1204Z.
At 1144Z at KLAX, the marine layer was 3500 ft deep. The top of
the inversion was 4700 feet with a temperature of 17 C.
Moderate to high confidence in TAFs for KPMD and KWJF, there is a
slight chance of rain showers after 00Z Sat.
Low to moderate confidence in remainder of TAFs. Timing of flight
cat changes may be off by +/- 2 hours, and conditions may be off
by 1 flight category than forecast at times. There is a 30% chance
of a couple hours of VFR conds at KCMA, KOXR, KSMO and KLAX, and
a 30% chance of little to no clearing at KSBA, KLGB, KVNY and
KBUR.
KLAX...Low to moderate confidence in TAF. There is a 30% chance
of a couple hours of VFR conds late this afternoon. An east wind
component of 8 kt is possible until as late as 21Z Fri.
KBUR...Moderate confidence in forecast. Cigs will be between
OVC008-OVC028 through the period, and there is a 30% chance little
to no clearing today.
&&
.MARINE...26/316 AM.
Small Craft Advisory (SCA) level northwest winds are expected to
drop off by mid- morning today across the Outer Waters south of
Point Sal. Otherwise and elsewhere winds are likely to remain
below SCA level through Tuesday night.
Thunderstorms will be possible south of Point Conception Saturday
into Saturday night.
Seas will peaking at around 6 to 9 feet on Saturday for the Outer
waters. Sunday into early next week, southerly swell up to 4 to 7
feet may impact all of the coastal waters.
&&
.BEACHES...26/320 AM.
A moderately-long period southerly swell will develop across the
coastal waters Sunday into early next week, generated by
Hurricane Narda. Hazardous rip currents and elevated surf are
likely for south-facing beaches, especially across Los Angeles and
Ventura Counties as well as Avila Beach and Port San Luis for the
Central Coasts. Additionally, particularly vulnerable south-
facing beaches may see shallow coastal flooding over normally dry
beach areas. A High Surf Advisory (or a Beach Hazards Statement)
may be needed for the peak of the event (Sunday through Tuesday).
A Coastal Flood Advisory is no longer anticipated to be needed at
this time.
&&
.LOX WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
PZ...Small Craft Advisory in effect until 9 AM PDT this morning
      for zones 673-676. (See LAXMWWLOX).
&&
$$
PUBLIC...Kittell/Cohen
AVIATION...Schoenfeld
MARINE...Schoenfeld
BEACHES...Schoenfeld
SYNOPSIS...Kittell
weather.gov/losangeles
Experimental Graphical Hazardous Weather Outlook at:
https://www.weather.gov/erh/ghwo?wfo=lox

NWS LOX Office Area Forecast Discussion