Santa Monica, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

713
FXUS66 KLOX 221307
AFDLOX

Area Forecast Discussion...UPDATED
National Weather Service Los Angeles/Oxnard CA
507 AM PST Sun Dec 22 2024

.SYNOPSIS...22/340 AM.

A significant high surf event with coastal flooding is expected
through the week, with the most dangerous conditions expected
Monday and Tuesday. Patchy fog near the coast will create low
visibilities at times through Monday. Aside from a small chance
for light rain near San Luis Obispo County coast this morning, it
will be dry through Monday. A stronger weather system will bring
light rainfall to more areas Tuesday and Tuesday night.
Temperatures will range from near normal near the coast, to well
above normal for interior areas.

&&

.SHORT TERM (TDY-TUE)...22/450 AM.

***Significant high-surf event with coastal flooding expected this
 week, with the most dangerous conditions Monday into Tuesday***

High level clouds are streaming over the region this morning and
will lead to a partly to mostly cloudy day. These higher clouds
are currently limiting the formation of low clouds and fog, but
gaps in the higher clouds as the day breaks may lead to some
patchy fog and low clouds sneaking in this morning (more so for
S. of Pt Conception than northward). Temperatures will be similar
to yesterday with the high clouds prohibiting solar heating,
resulting in highs generally in the 60s range with the valleys
reaching into the 70s. This afternoon through evening, northerly
flow will settle in, with sub-advisory winds affecting the
mountains of SBA and VTA, as well as the I-5 corridor and Antelope
Valley. As for rain, A weak system moving over northern SLO
County this morning has already brought some very light rain and a
slight chance will continue through the mid- morning hours.
Elsewhere and otherwise, conditions are forecast to remain dry
through Monday.

Pretty benign weather on track for Monday. The aforementioned
higher clouds will thin out overnight tonight, and given the time
of year and weak gradients, patchy dense fog and low clouds have a
higher chance of making a return tonight, possibly even pushing
into the valleys. Temperatures will have the chance to warm up
Monday with the lack of high level clouds, bringing highs at the
coasts into the low to mid 60s, while valleys will be in the 70s,
and the warmest valleys in the mid to high 70s.

Tuesday will be the most interesting day weather-wise in the
short term forecast. A trough extending from a low pressure system
over the Pacific NW will cross the region, bringing rain chances
further south and into L.A. County. Rain amounts are expected to
be a half to one inch across coastal SLO county, then dropping
off quickly to around a quarter inch or less in Santa Barbara
County, Eastern Ventura, and across the eastern San Gabriel
Mountains. Elsewhere, around a tenth of an inch or less is likely.
The slight southerly component of this system will cause the
south facing mountains south of Pt. Conception to have slightly
higher rain totals. The system will cause high temps to crash
around 5 to 10 degrees compared to Monday, resulting in temps in
the 60s range, to 50s across the higher elevations and at the
immediate coasts.

Please reference the High Surf Warning and High Surf Advisory, as
well as the Coastal Flood Advisory, regarding the significant
high-surf event.

.LONG TERM (WED-SAT)...22/506 AM.

Following the system, winds will start to pick up in the evening
on Tuesday with moderate to locally strong northerly flow settling
across the area. Winds will pick up that evening with the
strongest winds in the mountains/canyons, including the Santa Ynez
Range, where some Wind Advisories may be needed into
Wednesday/Christmas morning. Christmas day will be sunny but
remain on the cooler side. The GFS/ECMWF deterministic models show
a ridge gradually building over the area through the week after
the trough passes through Tuesday. Periods of gusty winds will
continue all week with a slow warming trend going into next
weekend. Longer range ensembles show very little in terms of
precipitation chances through the first week in 2025. Possibly a
couple very weak systems for the Central Coast Thursday night,
next weekend, and early the following week but these show little
hope of bringing any meaningful rain.

&&

.AVIATION...22/0003Z.

At 23Z at KLAX, the marine layer was 400 ft deep. The top of the
inversion was at 2200 ft with a temperature of 18 C.

Overall, moderate confidence in 00Z TAF Package. High confidence
for desert sites and KSBA, KBUR, KVNY. Moderate to Low confidence
for remaining sites.

After 06Z, there is a 20 to 30% chance of LIFR conds at cig/vsby
restricted sites. There is a 10 to 20% chance for VLIFR conds
after 10z.

Timing of Cigs/vsby restrictions may be off +/- 2 hours. Flight
cats could be off one or two, especially during worst conditions.

KLAX...Low confidence in 00Z TAF. VLIFR to IFR conds should
persist through 18Z-19Z then improve to MVFR. There is a 30%
chance for vsbys less than 1/2SM and cigs VV001-VV002 after 07Z.
Low confidence in the minimum flight cats after 00Z Monday till
the end of the fcst pd. No significant east wind component
expected.

KBUR...High confidence in 00Z TAF.

&&

.MARINE...21/831 PM.

Buoy observations indicate that seas are building on schedule with
high confidence that these large, long period west to northwest
swells will last through next week. Seas will peak at 15 to 20
feet across our Outer Waters, with the largest swells in our
Northern Waters. For our Inner waters, seas will peak around 12
feet for the Santa Barbara Channel and the waters west of Catalina
Island bordering PZZ676.

Between the Peaks, small craft advisory (SCA) seas will likely
persist (70-80% chance) widespread across much of our Outer
Waters through next week. These conditions pose a risk for
damaging breaking waves at Morro Bay and Ventura Harbor
entrances.

Alongside high seas, there is roughly a 70% chance of SCA level
winds for the waters around the Channel Islands beginning tomorrow
morning and persisting through at least Monday evening. By
Christmas Eve (Tuesday), we can expect SCA level winds to become
widespread across most of the coastal waters through at least
Thursday morning (80-90% chance). There is a 20% chance of GALE
force Gusts from around Point Conception south to San Nicolas
Island Wednesday morning into Thursday.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...High Surf Advisory in effect until 4 AM PST Wednesday for
      zones 87-349-350-362-366. (See LAXCFWLOX).
     High Surf Warning in effect until noon PST Tuesday for zones
      340-346-354. (See LAXCFWLOX).
     Coastal Flood Advisory in effect until 9 AM PST Tuesday for
      zones 340-346-354. (See LAXCFWLOX).
PZ...Small Craft Advisory in effect until 2 AM PST Thursday for
      zones 645-670-673-676. (See LAXMWWLOX).
     Small Craft Advisory in effect until 4 AM PST Monday for zone
      650. (See LAXMWWLOX).

&&

$$

PUBLIC...Lund/MW
AVIATION...Black
MARINE...Black
SYNOPSIS...Phillips/KL

weather.gov/losangeles

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