399
FXUS66 KLOX 031656
AFDLOX

Area Forecast Discussion
National Weather Service Los Angeles/Oxnard CA
956 AM PDT Thu Apr 3 2025

.SYNOPSIS...03/956 AM.

Showers are likely today with possible thunderstorms across the
mountains and spilling into the valleys and even parts of the
coast. Though some areas, especially the coastal areas, will
remain dry. Dry weather is expected starting Friday and lasting
through next week. A strong warming trend will begin Friday and
will continue through late next week with only a one day break on
Monday. Well above normal temperatures are very likely next
Tuesday and Wednesday with highs in the 90s expected across the
valleys.

&&

.SHORT TERM (TDY-SAT)...03/952 AM.

***UPDATE***

No changes to the current forecast. Already starting to see some
small cumulus developing across LA County coast and valley areas
which is good sign that there will be at least some shower
activity by this afternoon. HREF still indicating the potential
for as much as a half inch per hour across the northern San
Fernando Valley and San Gabriel Valley as the storms make their
way south from the mountains. CAPE values between 400-600 J/km are
pretty high for our area and certainly worth paying close
attention to. Thunderstorms are a strong possibility as well with
gusty winds and possibly small hail as well. Wouldn`t want to
totally exclude those rates from other areas but certainly
confidence is a little higher there due to the mountain proximity
and at least a few consistent runs favoring that area.

Outside of those areas, lighter showers are expected all the way
from the Central Coast through Santa Barbara County, the Ventura
Mountains and spilling over into the northern Ventura County
valleys, the Santa Monican Mountains, as well as Downtown LA and
possibly even towards the coast.

***From Previous Discussion***

Ydy`s showers have tapered off. Quite a bit of cloudiness remains
over SLO and SBA counties with VTA and LA counties under clear
skies. The persistent upper low over NV will finally begin to move
to the east. It will, however, deliver one last shot of PVA and
instability to the region this afternoon and early evening. Due
the eastward progress of the low this afternoon`s activity will be
focused over Nrn VTA county and most of LA county. The best chc of
convective activity will be over the mtns but there is a 25
percent chc that the showers or TSTMs will move off of the mtns
and into the vlys and perhaps into DTLA. Rainfall rates under the
heavier showers will be near a half inch per hour. The storms will
be moving along at a decent clip pushed along with about a 30 mph
upper level flow. This means that any one cell will not likely
produce any hydrologic problems. There is, however, a chance that
multiple cells will train over a single area and this could create
some flooding issues. Snow levels will be near 5000 ft but could
lower to 4000 ft under a heavy convective burst.

The clouds and showers over LA county will linger into the evening
but then will diminish.

A ridge will slowly build into the area on Friday and Saturday.
Weak offshore flow will develop as well. Skies will be mostly
clear through the period. The rising hgts, offshore flow and early
April sunshine will all combine to bring 3 to 6 degrees of warming
each day. Below normal temperatures will continue on Friday but
Saturday`s warming will bring most temps up to 2 to 3 degrees over
normal. Highs Saturday across the csts and vlys will mostly be in
the 70s with an outside chc of lower 80s in the warmest vly
locations.

.LONG TERM (SUN-WED)...03/321 AM.

The xtnd forecast is all about the heat. The ridge will peak on
Sunday and then will be knocked down some on Monday as a trof
passes well to north. The lower hgts will make Monday the only day
of the 4 that does not see warming temps. A stronger ridge builds
in starting Tuesday and continues through Thursday.

Weak offshore flow will continue through the period. Skies will be
mostly clear. The forecast does not contain any low clouds but
there is 20 to 30 percent chc of some clouds each morning esp over
Srn LA county and western SBA county.

Look for 2 to 4 degrees of warming on Sunday which will push vly
temps into the lower 80s with isolated mid 80s. 3 to 6 degrees of
cooling is slated for Monday with the trof and some onshore flow.
Then the serious warming begins with 3 to 6 degrees of warming
Tue and 4 to 8 additional degrees on Wed. Most temps on Wed will
be 10 to 15 degrees above normal with mostly mid 70s to lower 80s
near the coast and mid to upper 80s further inland. The vlys will
be in the upper 80s through the mid 90s.

&&

.AVIATION...03/1557Z.

At 1545Z at KLAX, there was no marine inversion or marine layer.

Moderate to high confidence in 18Z TAF package. Overall, high
confidence in VFR conditions for all sites through the period, but
there will be a 20-30% chance of MVFR/IFR conditions 08Z-17Z at
KSMO/KLAX/KLGB.

There is a 20-30% chance of showers and thunderstorms 20Z-04Z
across the mountains of LA and Ventura counties and any showers or
thunderstorms that develop could drift over coastal/valley sites
across Ventura/LA counties.

KLAX...Overall, high confidence in 18Z TAF. There is a 10-15%
chance of showers and thunderstorms 20Z-03Z. For tonight, there
is a 20-30% chance of MVFR/IFR CIGs/VSBYs 08Z-17Z. No significant
easterly wind is expected.

KBUR...Overall, high confidence in 18Z TAF. There is a 20% chance
of showers and thunderstorms 20Z-03Z.

&&

.MARINE...03/857 AM.

For the Outer Waters, moderate to high confidence in current
forecast. Today through Friday night, high confidence in Small
Craft Advisory (SCA) level winds. On Saturday, there is a 30%
chance of SCA level winds continuing. On Sunday, high confidence
in winds and seas remaining below SCA levels. For Monday, there
is a 60-80% chance of SCA level winds developing.

For the Inner Waters north of Point Sal, moderate to high
confidence in current forecast. Today through Friday, there is a
60-80% chance of SCA level winds in the afternoon and evening
hours. For Saturday and Sunday, high confidence in winds and seas
remaining below SCA levels. On Monday, there is a 50-70% chance of
SCA level winds in the afternoon and evening hours.

For the Inner Waters south of Point Conception, moderate to high
confidence in current forecast. For the western half of the Santa
Barbara Channel, there is a 60-70% chance of SCA level winds late
this afternoon evening then a 50-60% chance of SCA level winds
late Friday afternoon and evening. Otherwise across the southern
Inner Waters, high confidence in winds and seas remaining below
SCA levels through Monday.

Dense fog may develop this upcoming weekend, especially in the
evening to morning hours, in response to a ridge building over
the region.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
PZ...Small Craft Advisory in effect until 3 AM PDT Friday for
      zones 645-676. (See LAXMWWLOX).
     Small Craft Advisory in effect until 9 PM PDT this evening
      for zone 650. (See LAXMWWLOX).
     Small Craft Advisory in effect until 11 AM PDT Friday for
      zones 670-673. (See LAXMWWLOX).

&&

$$

PUBLIC...MW/Rorke
AVIATION...RAT
MARINE...RAT
SYNOPSIS...MW

weather.gov/losangeles

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