481
FXUS66 KLOX 061136
AFDLOX

Area Forecast Discussion
National Weather Service Los Angeles/Oxnard CA
436 AM PDT Mon May 6 2024

.SYNOPSIS...06/426 AM.

A warming trend will establish through Wednesday as area sits
between high pressure to the west and a trough to the east. Gusty
northerly winds are expected at times, especially in the
mountains and in southern Santa Barbara County. A return of low
clouds and fog is expected through the week, possibly extending
into the valleys over the weekend.

&&

.SHORT TERM (TDY-WED)...06/428 AM.

The satellite imagery shows the region sitting in zonal flow
between an upper-level ridge of high pressure building into the
eastern Pacific Ocean and an upper-level trough over the northern
Intermountain Region. Clearer skies and less wind across the area
is setting up for a cool start to a May morning. Some wind
sheltered areas are dipping down to the mid 30s to lower 40s to
start today. With several hours until daybreak, a frost advisory
was added for the coldest areas in the northern interior valleys
through 8 am PDT this morning.

A northerly surface pressure gradient remains across the area in
the wake of yesterday`s cold front. The gradient has relaxed some
this morning, and some the wind advisories have been allowed to
expire. Winds are still remaining just strong enough through the
Interstate 5 Corridor this morning to keep the wind advisory in
place. Some weakening of the winds will continue through this
morning, then the gradient will tighten again this afternoon into
this evening. A wind advisory was extended for the Interstate 5
Corridor through 3 am PDT Tuesday, and reissued for southwestern
Santa Barbara County from 4 pm PDT this afternoon through 3 am PDT
Tuesday morning. There is a chance that the southeastern portion
of Santa Barbara County could see some another round of gusty
winds late tonight, but the chances looks less at this time.
Surface pressure gradients, local 3-km WRF, and EPS ensemble
members all indicate gusty northerly winds lingering across
southern Santa Barbara County and into the Interstate 5 Corridor
again Tuesday night and into Wednesday morning, so there will
likely be another round of wind advisories across the same areas.

With the ridge aloft to the west of the area, a warming trend will
take shape over the coming days with mostly sunny skies continuing.
Temperatures will warm to near to slightly above normal for most
areas on Tuesday and above normal on Wednesday. Marine layer
induced stratus clouds will likely be kept a bay (and very patchy
at best) today due to a weaker marine inversion, but low clouds
and fog could make a patchy appearance on Tuesday morning across
the South Coast of Los Angeles County. The chances for low clouds
and fog will increase through the week with the best chance for
any low clouds and fog in the short term on Tuesday night and into
Wednesday morning across the Los Angeles County coast and
possibly extending into the Ventura County beaches.

.LONG TERM (THU-SUN)...06/435 AM.

There is still a good amount of uncertainty in the long term
period. Models are struggling to handle a retrograding upper-
level trough of low pressure late in the week. The forecast
ensembles are still trending higher with temperatures away from
the coast while leveling off the warming trend along the coastal
sections toward the weekend. There are still about a fifth of the
solution going warmer for late week at the coast, but most trend
cooler with increasing cloud cover means. Interior portions of the
area have a good chance of seeing a steady warming trend through
the week. For the current time, temperatures go with NBM values
and moderate the warming trend toward at the coast into the
weekend, while the forecast reintroduces a mention of low clouds
and fog over the weekend.

&&

.AVIATION...06/0253Z.

At 0018Z at KLAX, there was no marine layer. The top of the
inversion was at 1000 ft with a temperature of 16 C.

Moderate to high confidence in TAFs. Timing of wind changes could
be off by +/- 2 hours, and +/- 5 kt gusts. There is a 10-20%
chance of IFR- VLIFR conds for KPRB and KSMX 08Z-17Z, and 20%
chance of MVFR cigs at KSMO, KLAX, KLGB, and KVNY 10Z-16Z. Gusty W
to NW winds will affect much of the region thru early tonight
with areas of LLWS, turbulence and mdt UDDF.

KLAX...Moderate confidence in TAF. There is a 10-20% chance of
bkn018-025 cigs 10Z-16Z Mon. There is a 20% chance of northerly
cross winds to 12-18 kt through 07Z, and a 20% chance of an E
wind component of 7-8 kt 08Z-17Z Mon.

KBUR...Moderate confidence in TAF. There is a 10-20% chance of
bkn018-025 cigs 10Z-16Z Mon. There is a 30% chance of NW wind
gusts to 25 kt through 04Z Mon and again 16Z-02Z Mon.

&&

.MARINE...05/827 PM.

In the Outer Waters, moderate to high confidence in the forecast.
In the southern two zones (PZZ673/676), Gale force winds will
continue through tonight. Elsewhere and otherwise, Small Craft
Advisory (SCA) level winds (and seas at times) are expected thru
Wed night, with a 40% chance of SCA conds (mainly seas) continuing
Thu. There is a 20% chance of Gale Force wind gusts across the
waters south of Point Sal on Mon afternoon into Mon night, and a
50% chance for all outer waters Tue afternoon into Tue night.
Winds and seas should remain below SCA levels Thu night thru Sat
morning.

For the Inner Waters N of Pt. Sal, moderate to high confidence in
the forecast. Thru Wed night, winds are expected to reach SCA
levels during the afternoon/eve hours. Seas may remain at or above
SCA levels Mon night thru Wed morning, even when the winds
decrease. Then, conds should remain below SCA levels Thu night
thru Sat morning.

In the Inner Waters S of Pt. Conception, moderate confidence in the
forecast. Expect Gale force winds to continue tonight across the
western portion of the Santa Barbara channel. Otherwise, look
for SCA level winds to continue tonight across eastern portions of
the channel and zone 655. SCA conds are likely (70% chance)
across the Western SBA Channel during the late afternoon thru late
night hours Mon and Tue, with a 30-40% chance of SCA conds during
these times in the eastern portion of the SBA Channel and western
portions of the southern inner waters.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...Frost Advisory in effect until 8 AM PDT this morning for
      zones 38-343-344. (See LAXNPWLOX).
     Wind Advisory remains in effect from 4 PM this afternoon to 3
      AM PDT Tuesday for zones 349-351. (See LAXNPWLOX).
     Wind Advisory remains in effect until 3 AM PDT Tuesday for
      zones 377-378. (See LAXNPWLOX).
PZ...Small Craft Advisory in effect from 3 PM this afternoon to 9
      PM PDT this evening for zone 645. (See LAXMWWLOX).
     Small Craft Advisory in effect from 3 PM this afternoon to 3
      AM PDT Tuesday for zone 650. (See LAXMWWLOX).
     Small Craft Advisory in effect until 3 PM PDT Tuesday for
      zone 670. (See LAXMWWLOX).
     Gale Watch in effect from Tuesday afternoon through late
      Tuesday night for zone 670. (See LAXMWWLOX).
     Gale Warning in effect until 3 AM PDT Tuesday for zones
      673-676. (See LAXMWWLOX).

&&

$$

PUBLIC...Hall
AVIATION...Phillips/Lund
MARINE...Gomberg/Lund
SYNOPSIS...Hall

weather.gov/losangeles

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