556
FXUS66 KLOX 050644
AFDLOX

Area Forecast Discussion
National Weather Service Los Angeles/Oxnard CA
1044 PM PST Tue Feb 4 2025

.SYNOPSIS...04/957 PM.

A series of Pacific storm systems will move over the region
through late this week. Rain will continue to spread over the
area tonight and into early Wednesday along with gusty winds.
Rain will turn to showers on Wednesday. Rain chances will linger
into Thursday, then the next storm system will bring rain to the
area again Thursday night into Friday. A warming and drying trend
will establish over the weekend, then a weak weather system will
move into the region for early next week.

&&

.SHORT TERM (TDY-THU)...04/1043 PM.

Rain continues to spread over the area this evening as the first
of two Pacific storm systems advance over the region. A moist air
mass continues to stream over the area this evening. The latest
KVBG soundings indicate precipitable water value approaching 1.03
inches. Satellite-based precipitable water normal suggests the air
mass to be on the order of 150-200 percent of normal. This air
mass will continue to interact with the complex topography of
southern California. As this air mass is forced to lift over the
terrain, the unstable air mass aloft will interact with the
moisture to wring out the moisture as rain and high elevation
snow.

Hourly amounts have widely ranged between 0.10 to 0.25 inch
per hour, but a few locations have picked up hourly rainfall rates
between 0.50-0.71 inch per hour in San Luis Obispo County
earlier. The latest high-resolution models continue indicate the
heavier rain spreading south into southern Santa Barbara County
overnight. HRRR solutions continue to suggest isolated hourly
rainfall rates between 0.50 and 0.70 inch continuing through late
tonight. Otherwise for the remaining areas into the Southland, it
will very likely be beneficial light to moderate rain across the
area. With the latest high-resolution multi-model ensembles
showing very high probabilities of measurable rain across the
area, PoPs were increased to categorical across the coastal and
valley region into Wednesday, while trimming some chance in the
desert due to the high amount of orographic effects taking place.
Snow levels will remain high, keeping any snowfall on the highest
mountain roads such as Lockwood Valley Road in Ventura County, and
Highway 2, or Angeles Crest Highway in Los Angeles County. Snow
amounts should be on the lighter side with a few inches of
accumulation expected.

A high wind warning was added for the Santa Lucia mountains
earlier this evening as 850 mb winds approached 50 knots, while
wind advisories were expanded a little farther to the south in
southern Santa Barbara County, and into the Santa Monica mountains
and the Interstate 5 Corridor. No changes are planned for the wind
headlines at this time.

An update to the forecast was sent earlier and no additional
updates are planned.

***From Previous Discussion***

The storm is slowly moving into the area with light to moderate
rain across western SLO County since this morning. Rocky Butte in
the Santa Lucias is already at 1.22" as of 2pm while most other
areas are under a quarter inch. No significant changes to the
forecast today with forecast rain amounts and rates more or less
the same as has been advertised the last few days. The GEFS
ensemble system continues to be 50-75% less than most of the other
models including the EC ensemble mean and the higher res models
like the NAM and HRRR. The heaviest part of the storm will be
during the overnight hours into early Wednesday morning when the
combination of highest PW`s and strongest forcing develop. Rain
amounts will be highest in the Santa Lucias in NW SLO County where
3-6" are expected. Rain rates will be highest there as well as
the south facing slopes of the Santa Ynez Range where rates up to
or briefly exceeding a half inch per hour are possible. MUCAPEs
spike overnight along the Central Coast helping to boost rates.
Not expecting any thunderstorms but it wouldn`t be a complete
surprise either across the Central Coast.

Winds will be gusty across SLO and northern Santa Barbara Counties
this tonight and wind advisories and warnings are in effect.
Expecting those winds to drop off quickly after the front moves
through Wednesday morning.

For LA/Ventura Counties, amounts and rates drop off quite a bit
as the AR weakens as the storm advances to the southeast. 12z EC
ensembles actually bumped up amounts slightly across southern
areas but still in the quarter to one inch range, higher in
Ventura County and in the mountains. While there will be brief
periods of moderate rain across this area, rates are expected to
peak around a quarter inch per hour which is well below USGS
thresholds for potential debris flows, so chances remain very low
(5% or less) for any large scale flows in the recent burn areas.

This is a warm storm so little to no snow below 8000 feet.

There will be a brief 18-24 hour break before a second non-AR
storm moves in Thursday night into Friday. Rain amounts are
expected to be similar to slightly less across LA/Ventura Counties
and roughly 50% less across the Central Coast. Snow levels may
lower slightly but still mostly above 7500 feet.

.LONG TERM (FRI-MON)...04/223 PM.

All mdls show a rain free weekend with dry NW flow aloft. A little
trof ripples through the flow on Monday and brings a slight chc of
rain with it - mostly for the Central Coast.

Gusty north to northeast winds will develop later Friday Night
and continue into Sunday. The offshore push from the north is
forecast to reach between 7 and 8 mb with weaker flow from the
east. So this will likely be a more northerly type wind event with
the greatest affects over the typical wind prone areas such as
the I-5 Corridor, Ventura Valleys and southern Santa Barbara
County.

There will be some warming but max temps will mostly be in the
lower to mid 60s. There will be another round of chilly overnight
lows in the wind sheltered areas away from the coasts.

If you choose to believe 10 day forecasts the next storm is slated
for Valentines Day.

&&

.AVIATION...05/0606Z.

At 0505Z at KLAX, there was a 7000 ft moist layer with a weak
inversion above.

Low confidence in TAFs. There will be frequent category changes in
both cig and vis as well as periods of rain. Gusty SE to S winds
are expected during this timeframe with potential for LLWS and
turbulence especially for the Antelope Valley and near the
foothills and mtns.

KLAX...Low confidence in TAF. Cigs and Vis will vary frequently.
Conditions will be mostly be between BKN020-030, but cigs as low
as BKN006 are possible. VFR conds are also possible. There is a
moderate chc for a 10 kt east wind component 08Z-20Z.

KBUR...Low confidence in TAF. Cigs and Vis will vary frequently.
Conditions will be mostly be between BKN015-025, but cigs as low
as BKN006 are possible. VFR conds are also possible

&&

.MARINE...04/938 PM.

For the Outer Waters and Inner Waters along the Central Coast,
Small Craft Advisory (SCA) level winds are expected (>90% chance)
through Wednesday morning. Gusts from 25 to gale force strength
will be ongoing for all waters north of Point Sal through late
tonight. There is a 20-30% chance for GALES for northern portions
of PZZ673 (N of Pt. Arguello) for the aforementioned timeframe.
SCA level wind gusts should then persist into Wed afternoon. A
lull is then likely before a return of periods of SCA level winds,
and potential gales Friday into the weekend.

For the Inner Waters south of Point Conception, tonight through
Wednesday afternoon, there is a 60-80% chance for SCA winds
across the Santa Barbara Channel. There is 20-30% chance for
western portions of PZZ655. Sub advisory conds are expected
Wednesday night through Friday morning. NW winds should increase
Friday afternoon, bringing a 30-40% chance for SCA level conds
into the first half of the weekend.

Reduced visibilities in light to moderate rain can be expected
for much of the coastal waters for most of the waters north of Los
Angeles County, spreading to southern areas tonight and Wednesday.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...Wind Advisory in effect until 3 AM PST Wednesday for zones
      38-376-378. (See LAXNPWLOX).
     Wind Advisory remains in effect until 3 AM PST Wednesday for
      zones 340-341-343-346-347. (See LAXNPWLOX).
     High Wind Warning remains in effect until 3 AM PST Wednesday
      for zones 342-344-345-353-377. (See LAXNPWLOX).
     Wind Advisory in effect until 9 AM PST Wednesday for zones
      348>352-369-370-379>382. (See LAXNPWLOX).
PZ...Gale Warning in effect until 4 AM PST Wednesday for zones
      645-670. (See LAXMWWLOX).
     Small Craft Advisory in effect until 3 PM PST Wednesday for
      zones 650-673-676. (See LAXMWWLOX).

&&

$$

PUBLIC...Hall/MW
AVIATION...Rorke
MARINE...Phillips
SYNOPSIS...Hall

weather.gov/losangeles

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