Stevenson Ranch, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

330
FXUS66 KLOX 270724
AFDLOX

Area Forecast Discussion...UPDATED
National Weather Service Los Angeles/Oxnard CA
1124 PM PST Thu Dec 26 2024

.SYNOPSIS...26/109 PM.

Light rain is expected across portions of San Luis Obispo and
Santa Barbara Counties as well as the Grapevine region Friday and
again on Sunday, otherwise dry weather is expected through New
Years Day. Periods of gusty north winds are expected the next
several days.

&&

.SHORT TERM (THU-SUN)...26/802 PM.

***UPDATE***

Another pleasant if somewhat cloudy day. The offshore flow
allowed most cst/vly locations to warm 2 to 4 degrees. Rising hgts
and the lack of cooler air moving in from the interior brought 8
to 12 locally 18 degrees of warming to the inland areas. Most max
temps temps today ended up 2 to 5 degrees above normal.

Satellite shows the weak from moving towards SLO county (Note Well
the Vandenberg Radar is not working and radar mosaics for the
Central Coast will be missing this key data) Light rain will
likely (almost definitely for areas N of the city of SLO) develop
across the Central Coast. The chc of rain will diminish quickly
south of Point Conception with only a slight chc for VTA county
and a less than 10 percent chc for the non mtn areas of LA county.
The chc of rain will be confined to the mtns tomorrow morning.

Although winds are in a bit of lull now in the advisory areas They
will be picking up again as the front moves through.

Forecast is in good shape and will only be updated to add some
dense fog across the western portion of SBA county and to massage
the pops and clouds.

***From Previous Discussion***

Northern areas (including the Grapevine region) will get the tail
end of another weakening frontal band Friday morning with rain
amounts mostly under a tenth of an inch, except for the usual
upslope enhancement across far northwest SLO County where a half
inch could fall, all mostly before 10am. Could see some light non
measuring rain as far south as around Santa Barbara. The bigger
impact will be to inject another burst of north winds through the
passes and canyons, especially the Santa Ynez Range and I5
corridor where gusts up to 50 mph are possible. Some of those
winds will also filter down into the Santa Clarita and San
Fernando Valleys as well the Antelope Valley.

Dry with breezy north winds continuing into Saturday into same
areas. Outside of those areas it will be quite a nice day with
highs in the mid 60s coast to mid 70s valleys. That`s near normal
for the coast but 6-12 degrees above normal inland.

Sunday there will be another passing blow from a weakening system
along the Central Coast. Again very light rain expected with the
southern extent being around Santa Maria and rain amounts under a
tenth of an inch in those areas. High temperatures will be a few
degrees cooler than Saturday. And more northerly winds to follow
Sunday night into Monday.

.LONG TERM (MON-THU)...26/206 PM.

It`s going to be a dry pattern through next week with potentially
a moderate to strong north to northeast wind event Tuesday through
Thursday. The models are indicating it will start out as a north
wind event from southern Santa Barbara County through the
Grapevine region, then transition to a traditional Santa Ana event
New Years Day and Thursday across LA/Ventura Counties. There`s
still a fair amount of uncertainty with the strength of the winds
but confidence is high that winds will at least be in the advisory
category for both the north and northeast events with around a
30-40% chance of winds reaching 60 mph across the mountains based
on the latest ensemble wind projections. With most of the
ensembles favoring a building ridge through the period,
high temperatures across coast and valleys were nudged up several
degrees above the standard consensus blend for Wednesday and
Thursday, matching closer to the 75th or even 95th percentile
temps.

&&

.AVIATION...27/0722Z.

At 0614Z at KLAX, the marine layer was 2400 ft deep. The top of
the inversion was at 3400 ft with a temp of 15 deg C.

Overall, moderate confidence in TAF package. Winds speeds may be
off by 5 kts during peak winds at KPMD and KWJF. Best rain
chances for KSBP and KSMX, lower for KPRB, KSBA. Timing of
cigs/vsby restrictions may be off +/- 2 hours, with flight cats
being off one or two, especially during worse conditions. There is
a 20% chance of no MVFR developing for LA County tonight.

KLAX...Good confidence in the TAF. There is a 20% chance of an
east wind component of 6-8 kt from 13Z-18Z.

.KBUR..High confidence in the TAF. There is a 20% chance of no
OVC025 cigs developing.

&&

.MARINE...26/755 PM.

For the outer waters, there is high confidence in the current
forecast. Expect a series of large westerly swells to continue
propagating into the waters for the next several days. Whether it
be wind and/or seas, expect Small Craft Advisory (SCA) conditions
through Monday night. There is a 40-50% chance that SCA level wind
gusts could continue Tue and Tue night.

For the inner waters north of Point Sal, expect SCA conds (seas
and/or wind at times) to persist through at least Monday
afternoon.

For the inner waters south of Point Conception, Winds and/or seas
will be at SCA levels through Friday night, with the strongest
winds in the Santa Barbara Channel. There may be a brief reduction
below SCA level winds thereafter. By Sunday afternoon/eve, there
is a 80% chance of SCA level winds to become widespread across
much of the Santa Barbara Channel.

For Monday thru Tuesday night, winds and seas should generally
remain below SCA levels, although the western portion of the
Santa Barbara Channel could see seas approach SCA levels at times.

&&

.BEACHES...26/755 PM.

A series of large and long period west to northwest swells will
bring high surf to the west-facing beaches of the Central Coast
and to Ventura County beaches thru early next week. Above normal
surf is also expected on west-facing beaches of the south Santa
Barbara County coast and the Los Angeles County coast through Sun
night.

Surf of 10 to 15 ft is expected much of the time thru Sun morning
on Central Coast beaches. The surf there should diminish some to
8 to 11 feet Sunday afternoon and continue into Mon night.

For the VTU County beaches, surf of 6 to 9 ft with local sets up
to 11 feet is expected through Sun then lower to around 5 to 7
feet Sun night and continue through Mon evening.

On west-facing beaches of L.A. County and west-facing points on
the south coast of SBA County, elevated surf of 3 to 6 ft is
expected thru the weekend. Local sets up to 7 feet will be
possible Friday on west-facing beaches of L.A. county as well.

Nuisance to minor coastal flooding may continue to affect beaches
on the Central Coast and Ventura County Coast around the time of
the early morning high tides thru the weekend. Please reference
our SRF and CFW products for details.

&&

.FIRE WEATHER...26/210 PM.

***Elevated to critical fire-weather conditions due to gusty north
 to northeast winds and low humidities across the mountains and
 foothills of Los Angeles, Ventura, and Santa Barbara Counties, in
 addition to Santa Ana wind-prone corridors at lower elevations,
 for Monday through next Thursday, January 2***

A prolonged period of gusty and potentially strong north to
northeast winds is expected to impact the region for early to middle
parts of next week. And with additional drying and a warming trend, a
long duration of elevated to critical fire-weather conditions could
materialize from Monday through next Thursday, January 2.

Confidence continues increasing that the weather pattern next week will
become increasingly favorable for elevated to critical fire-weather
conditions across Santa Ana wind-prone areas of Los Angeles and Ventura
Counties, as well as portions of Santa Barbara County prone to north-
wind enhancements. Next week, an upper-level ridge is forecast to
gradually build along the Pacific coast to the west of a large upper
trough encompassing much of the central and eastern states.
Correspondingly, surface high pressure strengthening over the Great
Basin will facilitate increasing offshore flow amid slight to moderate
upper support, which will combine with unseasonably warm temperatures
assisted by the building upper ridge to produce the increased fire-
weather risk. LAX-Bakersfield offshore gradients are currently forecast
to reach 5-7 mb starting Monday, with LAX-Daggett offshore gradients
reaching 4-5 mb starting Tuesday. Given the enhanced northerly pressure
gradients, wind directions could be 10-20 degrees more northerly than
easterly for this event compared to other November and December 2024
events, especially early on.

The greatest potential for critical fire-weather conditions would
include areas prone to a moderate Santa Ana wind event, for Tuesday
through next Thursday, January 2. This includes the mountains and
foothills of Los Angeles and Ventura Counties, and extending through
lower elevations prone to moderate Santa Ana winds. While there is
increasing confidence in these conditions materializing, differences
among weather-model solutions regarding the details of the pattern at
this far of a time range cast uncertainty on the critical fire-weather
risk at this time. As a result, potential issuance of fire-weather
headlines will be re-evaluated in subsequent forecasts. Present
indications are that fire-weather headlines will be possible --
40-60 percent chance.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...High Surf Advisory in effect until 3 AM PST Tuesday for zones
      340-346. (See LAXCFWLOX).
     Wind Advisory remains in effect until noon PST Friday for
      zones 349-351>353. (See LAXNPWLOX).
     Beach Hazards Statement in effect through Sunday evening for
      zones 349-350. (See LAXCFWLOX).
     High Surf Advisory in effect until 9 PM PST Monday for zone
      354. (See LAXCFWLOX).
     High Surf Advisory in effect until 3 AM PST Monday for zones
      362-366. (See LAXCFWLOX).
     Wind Advisory remains in effect until 10 PM PST Friday for
      zones 376>378. (See LAXNPWLOX).
     Wind Advisory remains in effect from 10 AM to 10 PM PST
      Friday for zones 381>383. (See LAXNPWLOX).
PZ...Small Craft Advisory in effect until 3 PM PST Monday for zone
      645. (See LAXMWWLOX).
     Small Craft Advisory in effect until 3 AM PST Saturday for
      zones 650-655. (See LAXMWWLOX).
     Small Craft Advisory in effect until 3 AM PST Tuesday for
      zones 670-673-676. (See LAXMWWLOX).

&&

$$

PUBLIC...MW
AVIATION...Schoenfeld
MARINE...Black
BEACHES...Sirard/Black
FIRE...Cohen
SYNOPSIS...MW/Schoenfeld

weather.gov/losangeles

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