714
FXUS66 KLOX 130037
AFDLOX

Area Forecast Discussion...UPDATED
National Weather Service Los Angeles/Oxnard CA
537 PM PDT Wed Jun 12 2024

.SYNOPSIS...12/123 PM.

Low clouds and fog are expected through at least Friday morning
across coast and coastal valleys with temperatures 3-6 degrees
below normal. Gusty north winds are expected Friday into the
weekend, mainly in the mountains and southern Santa Barbara County
and adjacent coastal waters. Warming temperatures are expected
Friday through weekend, with faster clearing of low clouds.

&&

.SHORT TERM (TDY-SAT)...12/207 PM.

While significant warming is on the way, we are still looking at a
couple days of similarly cool temperatures, long lasting low
clouds and fog, and possibly some morning drizzle. An upper low
that has been spinning a few hundred miles southwest of KLAX will
finally start moving towards the coast later tonight and pass
overhead Thursday afternoon based on all the latest ensemble
forecasts. We`re still seeing onshore trends in the gradients
which is indicative of an approaching trough, and overnight there
should be a corresponding increase in marine layer depth. With
this in mind we may see an increase in drizzle later tonight and
Thursday morning across coast and valleys. Likely won`t see it
everywhere in those locations as the low won`t pass directly
overhead until the afternoon, but the pattern seems favorable for
at least spotty drizzle tonight and Thursday morning. And to go
along with that, a deeper marine layer will mean slower clearing
and cooler temperatures.

Changes start happening rapidly Friday after the low zips off into
AZ. Northerly flow will quickly be ramping up over the northern
coastal waters and by Friday evening models are showing solid gale
force winds. The northerly flow will also be impacting the
western portions of SLO and SB Counties, generating some gusty
Sundowner winds and downslope warming off the Santa Lucia and
Santa Ynez Ranges Friday into Friday night. Will certainly be
needing wind advisories across those areas with around a 30-40%
chance of gusts to around 60 mph (warning level) in the more
favorable north wind areas such as the hills above Montecito. At
the same time models show very warm temperatures developing during
the evening and overnight periods and this looks like a situation
where temperatures stay in the 80s and possibly even low 90s
throughout much of the night in the Santa Ynez Range and even
down into the coastal plain. Advisory level winds also expected
across the northern Ventura mountains and the Grapevine areas.
Some of those winds will filter down into the LA valleys but
probably not stronger than 30 mph.

Marine layer stratus will be quickly dissipating from the north
Friday and most areas should see much earlier clearing. By
Saturday morning stratus coverage will either be zero or just
minimal clouds across the coast from LA to Ventura county.
Saturday will be a much warmer day for most areas. Warmest
locations will be in the Sundowner areas where highs in the 80s
and lower 90s are likely, even at some beach areas in SLO and SB
Counties. This may require the issuance of heat advisories for
parts of the Central Coast and southern Santa Barbara County with
highs 15-20 degrees above normal. Elsewhere, warmer valleys also
expected to be in the 90s and coastal areas in the 70s to lower
80s.

Another round of warm and gusty Sundowner winds are expected
Saturday night.

.LONG TERM (SUN-WED)...12/230 PM.

Sunday will be an interesting day as there will still be strong
northerly winds continuing across the western counties, adjacent
coastal waters, and the northern mountains. However, models have
been consistent showing the development of a coastal eddy
circulation developing off the coast of LA and Orange Counties and
significant cooling at least for LA/Ventura County coast and
valley areas. And most of the models are even showing several
degrees of cooling across inland areas of LA/Ventura Counties as
well. Will likely still see advisory level Sundowner winds again
Sunday into Monday for the Santa Barbara area but probably not
quite as warm as the previous couple days. With the eddy
developing later in the weekend will likely see marine layer
stratus moving up from the south and into coastal LA/Ventura
Counties.

Northerly flow expected to remain quite strong across the offshore
coastal waters through the middle of next week, which will keep at
least a threat of Sundowner winds going for southern Santa Barbara
Counties going into next week as well. For this reason, stratus
coverage should be confined to just LA/Ventura Counties at least
for the first half of the week. Temperatures in these areas will
drop back to normal or slightly below normal levels.

For SLO and northern Santa Barbara Counties, gusty northwest winds
will continue, especially near the coast, but little or no marine
layer stratus is expected. Temperatures will generally be within a
few degrees of normal.

&&

.AVIATION...13/0037Z.

At 2233Z at KLAX, the marine layer was 1300 ft deep. The top of
the inversion was at 3200 ft with a temperature of 24 C.

High confidence in desert TAFs.

Low to moderate confidence in all other TAFs due to uncertainty in
CIG heights and timing of flight cat changes (which could be off
by +/- 2 hours). There is a 40% chance that KPRB could remain VFR
through the period. There is a 30% chance that KSMX could lower
to LIFR 07-15Z. DZ possible at all TAF sites (except desert) late
night into morning. There is a 30-40% chance of IFR conds for LA
coastal TAF sites and KBUR/KVNY 09Z-15Z.

KLAX...Moderate confidence in TAF. There is a 40% chance of BKN008
cond 09Z-15Z Thu. Any east wind component should remain weaker
than 7 kt.

KBUR...Moderate confidence in TAF. There is a 40% chance of BKN008
conds 09Z-15Z Thu.

&&

.MARINE...12/125 PM.

In the outer waters, high confidence in the forecast. Winds and
seas are expected to remain below Small Craft Advisory (SCA)
levels thru Thu afternoon, then an extended period of strong NW
winds is likely. SCA winds will occur starting Thu night,
increasing to Gale Force Friday afternoon with Gales continuing
into Monday afternoon. SCAs and Gale Watches have been issued.
There is even a 20-30% chance of STORM Force wind gusts (to 48 kt
or greater) at times Fri night thru Sun night, mainly during the
evening hours.

In the inner waters N of Pt. Sal, conditions will likely remain
below SCA levels thru Fri morning. SCA conds are likely (80% chance)
Fri afternoon thru Sun night. Winds may drop below SCA levels for
a few hours during the late night thru morning hours, but seas will
likely remain at or above SCA levels. There is a 40-50% chance of
Gale force winds during the afternoon/eve hours Sat and Sun.

In the Santa Barbara Channel, conds will likely remain below SCA
levels thru Thu afternoon. There is a 30% chance of SCA level
winds in western portions Thu night. SCA level winds are likely
(80% chance) across western portions of the SBA Channel during
the late afternoon thru late night hours Fri thru Sun, with a 40%
chance of Gale force winds during these hours Sat and Sun. In the
eastern portion of the SBA Channel, SCA conds are likely (60-70%
chance) during the late afternoon thru late evening hours Fri thru
Sun. Steep waves of 8 to 12 ft are likely late Fri thru Mon.

In the southern inner waters, forecast confidence is lower. There
is a 30% chance of SCA level W-NW winds in northwestern portions
Fri afternoon/evening, and a 60% chance of SCA conds Sat afternoon
thru Sun night, mainly from Anacapa Island to Malibu. There will
likely be steep and dangerous seas, possibly to SCA levels Sat-Mon.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
PZ...Small Craft Advisory in effect from 2 AM to 2 PM PDT Friday
      for zones 670-673-676. (See LAXMWWLOX).
     Gale Watch in effect from Friday afternoon through Monday
      afternoon for zones 670-673-676. (See LAXMWWLOX).

&&

$$

PUBLIC...MW
AVIATION...Lund
MARINE...DB/Cohen
SYNOPSIS...MW

weather.gov/losangeles

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