Leona Valley California Weather Forecast Discussion

918
FXUS66 KLOX 112231
AFDLOX
Area Forecast Discussion...UPDATED
National Weather Service Los Angeles/Oxnard CA
331 PM PDT Sat Oct 11 2025
.SYNOPSIS...11/324 PM.
Gusty northerly winds will increase through today, then shift to
northeast and weaken on Sunday. This will result in drying
conditions through the weekend. A storm system will move across
the area late Monday through Wednesday, with most of the rainfall
likely on Tuesday. Expect widespread light to moderate rain with
potential for locally heavy showers and thunderstorms.
&&
.SHORT TERM (TDY-TUE)...11/147 PM.
Overall, 12Z models in good synoptic agreement through the short
term period. At upper levels, broad cyclonic flow remains over the
area through Sunday then a potent upper low develops just off the
Northern CA coast Monday then dives southward into Central CA on
Tuesday. With this pattern, a combination of winds and
precipitation is on tap for Southwestern CA.
WINDS...
Strong northerly offshore pressure gradients and good upper level
support will generate gusty northwest to north winds through
tonight. The strongest winds, gusts 35-50 MPH with isolated gusts
to around 60 MPH, are expected across the entire Santa Ynez Range
as well as the I-5 Corridor through tonight with slightly weaker
winds across the Central Coast and Santa Clarita Valley. Due to
the expected wind gusts, WIND ADVISORIES remain in effect for
these areas through tonight. Check LAXNPWLOX for the details.
Late tonight/Sunday, the winds shift to the northeast with gusts
of 20-40 MPH likely in the Santa Ana wind-prone spots of Ventura
and LA counties. At this time, expect any advisory-level northeast
winds to remain very localized and no wind advisories will be
issued.
On Monday/Tuesday, south to southwest wind will increase across
the area in association with the upper low dropping down across
the state. Widespread wind advisories are likely across the
mountains and interior sections, especially Monday night and
Tuesday (and even a chance of some areas reaching warning levels).
PRECIPITATION...
All systems are "GO" for a rather potent early season storm for
the area Monday night through Tuesday night. Rain will begin
across San Luis Obispo county late Monday afternoon/evening then
spread south and east Monday night and Tuesday. No major changes
to thinking about rainfall totals with SLO/SBA counties getting
widespread 1.50-4.00 inch totals and Ventura/LA counties getting
widespread 0.75-3.00 inch totals. The highest amounts will occur
across the foothills due to good orographic lift.
Based on 12Z model guidance, it looks like there is a greater
chance for more significant rainfall rates. High resolution models
indicate a QLCS-type structure zipping across the area Tuesday
morning into the afternoon. If this feature verifies, rainfall
rates up to around 0.80 inches per hour will be possible.
Otherwise, rainfall rates are expected to be in the 0.10-0.50
inch per hour range. With those potential enhanced rainfall
rates, there could be some flash flooding and debris flow issues
Monday night and Tuesday.
As for thunderstorms, parameters are looking pretty decent. So,
have bumped up thunderstorm chances into the 25-35% range for
SLO/SBA counties and 15-25% range for Ventura county and far
western LA county. Along with brief heavy rainfall, any
thunderstorms could generate strong winds, small hail and even a
waterspout or a weak, short-lived, tornado.
Finally, looking at the 1000-500 MB thickness and Wet Bulb Zero
forecasts, snow levels are expected to drop into the 6000-7000
foot range on Tuesday. So, there is the potential for decent
snowfall accumulations (several inches) at the resort level.
Confidence in any exact amounts is low at this time, but the
potential will need to be monitored closely.
.LONG TERM (WED-SAT)...11/147 PM.
For the extended, 12Z models continue to exhibit good synoptic
agreement. At upper levels, low moves to the east on Wednesday as
a ridge builds over the Eastern Pacific Thursday through Saturday.
With this pattern, rather benign weather is expected. On
Wednesday, cool conditions are anticipated in the wake of the
upper low. However, do not anticipate any mentionable threat of
showers on Wednesday. For Thursday through Saturday, a warming
trend is expected with the ridge building offshore and limited
marine layer stratus. The ECMWF indicates a period of weak
offshore flow while the GFS indicates a more diurnal flow pattern.
So, there may be some areas of locally gusty offshore winds in the
Thursday-Saturday time frame.
&&
.AVIATION...11/1024Z.
Around 07Z, the marine layer depth was around 900 ft deep at KLAX.
The top of the inversion was near 1700 feet with a temperature of
24 degrees Celsius.
Moderate confidence in the current forecast. There is a low-to-
moderate chance of LIFR to IFR conditions at coastal terminals and
KPRB through 16Z. Otherwise, VFR conditions are expected. Periods
of moderate to strong low-level wind shear and turbulence are
possible near KSBA through 10Z Sunday. Periods of moderate to
strong low-level wind shear and turbulence are possible at all
terminals from 22Z through 10Z Sunday.
KLAX...There is a 40 percent chance of IFR conditions between 13Z
and 16Z. Wind impacts could be the main issue. While any easterly
winds are expected to remain below 7 knots this morning. There is
a high chance of significant north wind between 8 and 12 knots
with gusts potentially up to 20 knots from 02Z to 06Z Sunday, then
there is moderate chance of northeasterly winds between 7 and 10
knots thereafter. Periods of moderate low- level wind shear and
turbulence are possible near KLAX between 04Z and 08Z Sunday.
KBUR...VFR conditions are expected through the period. Periods of
moderate to strong low-level wind shear and turbulence are
possible near KBUR between 02Z and 10Z Sunday.
&&
.MARINE...11/105 PM.
For the outer waters southwest through northwest of the Channel
Islands, including the nearshore waters along the Central Coast,
Gale force winds will expand across the remainder of the waters by
mid-afternoon today and last through tonight. However, the
strongest winds will be from near Point Conception south to San
Nicolas Island, and will continue into Sunday night with winds
briefly dropping to Small Craft Advisory (SCA) late tonight into
Sunday morning. Otherwise, SCA level winds and seas will continue
through at least early Sunday morning, with a 40-60% chance of
lingering into late Sunday night or early Monday morning. Due to
the GALES and hazardous seas, inexperienced boaters should seek or
remain in safe harbor.
Inside the southern California bight, SCA level winds are expected
mainly across western portions of the bight, as well as the
southern portion of the Santa Barbara Channel and possibly across
the Anacapa passage. Short- period hazardous seas could develop
across the Santa Barbara Channel this evening, with winds and seas
potentially reaching Ventura County harbors, such as Ventura and
Channel Islands Harbor during this time. The strongest winds are
expected across the western portion of the Santa Barbara Channel,
where a moderate-to- high (30-50 percent) chance of GALES exists
this afternoon and evening.
Looking out at Monday night into Tuesday night, a storm system and
associated cold front will move across the region. With this cold
front brings a 20-40% chance of thunderstorms across the Santa
Barbara Channel, west past the Channel Islands, and northward to
the San Luis Obispo County Line. For the waters south of the Santa
Barbara Channel, including the waters nearshore LA and Orange
Counties, there is a 10-20% chance of thunderstorms. Any
thunderstorm that forms may be capable of frequent cloud to
surface lightning, gusty and erratic winds, small hail, and even a
waterspout. Additionally, widespread SCA level SW winds and seas,
with a moderate chance of GALES is expected between Monday night
and Tuesday night due to the aforementioned storm.
&&
.LOX WATCHES/WARNINGS/ADVISORIES...
CA...Wind Advisory remains in effect until 10 AM PDT Sunday for
      zones 88-349>353-375>379-381-383. (See LAXNPWLOX).
     Wind Advisory remains in effect until midnight PDT tonight
      for zones 340-341-346>348. (See LAXNPWLOX).
PZ...Gale Warning in effect until 3 AM PDT Sunday for zones
      645-670. (See LAXMWWLOX).
     Small Craft Advisory in effect until 3 AM PDT Monday for zone
      650. (See LAXMWWLOX).
     Small Craft Advisory in effect until 3 AM PDT Sunday for zone
      655. (See LAXMWWLOX).
     Gale Warning in effect until 3 AM PDT Monday for zones
      673-676. (See LAXMWWLOX).
&&
$$
PUBLIC...Thompson
AVIATION...Hall
MARINE...Hall/Lund
SYNOPSIS...RK/Schoenfeld
weather.gov/losangeles
Experimental Graphical Hazardous Weather Outlook at:
https://www.weather.gov/erh/ghwo?wfo=lox

NWS LOX Office Area Forecast Discussion