Area Forecast Discussion
Issued by NWS Los Angeles, CA

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FXUS66 KLOX 161846
AFDLOX

Area Forecast Discussion
National Weather Service Los Angeles/Oxnard CA
1146 AM PDT Mon May 16 2022

Updated Aviation and Hazards Section

.SYNOPSIS...16/138 AM.

Zonal to northwest flow will continue across the region for much
of next week. This will support a cooling trend through Tuesday
with an increase in northwest winds focused across the mountains
and the Santa Barbara county south coast. Low clouds and fog will
gradually return to many coastal and some valley areas through at
least Tuesday.

&&

.SHORT TERM (TDY-THU)...16/924 AM.

***UPDATE***

Marine layer clouds have begun to dissipate across coastal and
lower valley areas, tracking to clear for most areas by later this
morning. Areas within the marine layer will see highs in the 60s
and 70s today. 80s expected inland, extending into portions of
the South Coast thanks to sundowner winds. Isolated gusty winds to
around 40 mph were observed in southwest SBA county and northern
Antelope Valley foothills and surrounding area. Moderate northwest
to onshore surface pressure gradient trends support the slew of
advisories that expand across mainly mountains later today.
Although the LA/VTA mountain advisories are marginal with a 30 of
gusts largely remaining below advisory levels. Have decided to
drop the wind advisory (update to NPW to follow) for eastern
portions of the Santa Barbara county South Coast as the marine
layer presence there and a lack of a stronger northeast push will
likely limit any advisory level winds to the foothills at best.
The high wind warning for southwest SBA county looks good with the
typical windier locations from Refugio to Gaviota having a good
shot at wind gusts peaking between 50 and 60 mph later this
afternoon into tonight.

***From Previous Discussion***

A reinforcing shot of NW winds aloft and cold air advection will
bring a big boost in the north winds later this afternoon. Warning
level gusts to 60 mph will develop across the western SBA south
coast while the eastern portion will see gusts to 45 or 50 mph.
The I-5 corridor and the NW portions of the Antelope Vly will also
see advisory level gusts between 45 and 50 mph. Cool air
advection will lower max temps 4 to 8 degrees today every where
except for the SBA south coast and the Central Coast where there
will be offshore flow.

Tonight`s stratus pattern will be similar to this morning`s but
it will likely develop a little quicker as the eddy should spin up
faster due to stronger winds across the outer waters. The
afternoon`s wind warnings and advisories will continue into the
early hours of Tuesday morning (but not the Antelope Vly where
winds will subside by mid evening)

Short range deterministic guidance as well as ensemble based
metrics support the idea of weak troffing on Tuesday and weak
ridging on Wednesday. Ensemble based wind guidance shows another
round of advisory level sundowners across the SBA south coast on
Tuesday evening. Hier hgts and offshore trends will combine to
reduce the marine layer stratus pattern on Wednesday morning. The
troffing will bring cooling to the area. The SBA south coast will
really cool (12-15 degrees) due to lack of offshore flow. On
Wednesday the increased hgts will lead to about 6 degrees of
warming across the board.

.LONG TERM (FRI-MON)...16/316 AM.

he GFS and EC as well as their ensembles are in decent agreement
for Thursday and Friday but then the deterministic mdls diverge
and the ensemble spread grows over the weekend which leads to
decreased confidence for the weekend forecast.

Thursday looks to be a breezy day with the GFS forecasting an 10.5
mb onshore push to the east - the EC is a little tamer at 7 mb.
This strong an onshore push will likely bring advisory level wind
gusts to the Central Coast and the Antelope Vly. It will also
bring a powerful seabreeze and most areas can expect 2 to 4
degrees of cooling. Ensemble cloud forecast is underwhelming and
somewhat in contradiction to the amount of onshore flow forecast
would not be surprised if the morning is a little cloudier than
currently forecast. Most areas will likely cool a few degrees.

An inside slider moves down the CA/NV state line Thursday evening
and early Friday and sets up strong NW flow over the area. The
north push should limit stratus formation and will likely set up
another round of advisory level wind gusts across the SBA south
coast and the I-5 corridor. Max temps will wind up a few degrees
above normal esp south of Point Conception.

As mentioned above there is some disagreement for the forecast
next weekend. The EC and most of its ensembles are troffier and
cooler on Saturday with more stratus and stronger onshore flow. On
Sunday the situation is reversed with the GFS and the bulk of its
ensembles troffier and cooler while the EC has higher hgts and
warmer temps. Oddly the ensembles, when combined, forecast some
warming each day.

&&

.AVIATION...16/1845Z.

At 17Z at KLAX, the marine layer was 1800 ft deep. The top of the
inversion was at 3200 feet with a temperature of 19 Celsius.

High confidence in gusty W-NW winds 20-03Z KSBP KSMX KWJF KPMD.
Chance of BLDU vis under 6 miles at KWJF. Chance of sporadic
northwest gusts and LLWS 15-20 knots at KSBA 01-08Z.

Moderate confidence in VFR at all sites through 03Z. 20 percent
chance of BKN010 at KOXR KLAX at times through 22Z. Moderate
confidence in mostly similar CIG height, coverage, timing over
next 24 hours as previous 24 hours. 50 percent chance of brief
IFR/LIFR at KPRB 11-15Z. Chance of BKN008-12 at KVNY (20%) and
KBUR (40%). High confidence in VLIFR at KSMX early Tuesday.

KLAX...20 percent chance of an hour or two of BKN015 through 22Z.
Otherwise, moderate confidence of VFR through at least 05Z.
Moderate confidence in CIGS return 06-10Z and staying above 1000
feet. SE winds likely after 08Z, with a 40 percent chance of
reaching 10 knots 10-15Z.

KBUR...High confidence in VFR through at least 10Z. 40 percent
chance for a few hours of BKN008-012 starting 10-14Z. SE winds
will likely persist through most of the night.

&&

.MARINE...16/929 AM.

Gale force winds will be common through at least Thursday for the
outer waters from the Central Coast to San Nicolas Island. This
will create steep short period waves over all coastal waters
through at least Thursday, with ample white caps for hazardous sea
conditions.

For the nearshore waters along the Central Coast, Small Craft
Advisory (SCA) level winds are likely each day through at least
Thursday for the afternoon and evening hours.

For the Santa Barbara Channel, high confidence in Gale Force winds
this afternoon and night staying confined to the western half.
dangerous winds likely between the Channel Islands west of Santa
Cruz Island. Widespread steep waves likely. Winds should retreat
to the west starting Tuesday, but could affect the far western
portion.

For the Santa Monica Basin, San Pedro Channel, Orange County area,
high confidence in typical west afternoon winds (10 to 15 knots).
Local gusts to 25 kt possible beyond 20 miles from shore, and in
the San Pedro Channel this afternoon and night. Choppy seas likely
each afternoon and night. A Small Craft Advisory was issued to
address mainly for the choppy seas from nearby winds.

High confidence in all nearshore waters south of Point Conception
will see moderate southeast winds each morning, with isolated 15
to 20 knots possible near San Pedro and Point Mugu.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...Wind Advisory in effect from 3 PM this afternoon to 9 AM PDT
      Tuesday for zones 53-54. (See LAXNPWLOX).
     Wind Advisory in effect from 3 PM this afternoon to 3 AM PDT
      Tuesday for zones 59-352. (See LAXNPWLOX).
     Wind Advisory in effect until 3 PM PDT this afternoon for
      zones 349-351. (See LAXNPWLOX).
     High Wind Warning in effect from 3 PM this afternoon to 3 AM
      PDT Tuesday for zones 349-351. (See LAXNPWLOX).
PZ...Small Craft Advisory in effect until 3 AM PDT Tuesday for
      zones 645-655. (See LAXMWWLOX).
     Small Craft Advisory in effect until 1 PM PDT this afternoon
      for zone 650. (See LAXMWWLOX).
     Gale Warning in effect until 3 AM PDT Tuesday for zones
      650-670. (See LAXMWWLOX).
     Gale Warning in effect until 9 AM PDT Tuesday for zones
      673-676. (See LAXMWWLOX).

&&

$$

PUBLIC...Rorke
AVIATION...Kittell
MARINE...Hall/Kittell
SYNOPSIS...Munroe/TF

weather.gov/losangeles

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


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