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406
FXUS66 KLOX 291021
AFDLOX

Area Forecast Discussion
National Weather Service Los Angeles/Oxnard CA
321 AM PDT Mon Apr 29 2024

.SYNOPSIS...
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29/222 AM.

Mostly clear skies and warmer temperatures will prevail across
the region through this week, with just some night through
morning coastal low clouds and fog. Gusty northwest to north
winds will prevail over the mountains and deserts at least through
Tuesday.
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&&

.SHORT TERM (TDY-WED)...
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29/301 AM.

Not much going on for the next three days. Winds will be the only
concern. The state will be under NW slightly cyclonic flow through
the period with hgts near 576 dam today and Tue falling to 574 dam
on Wed. There will be continuous offshore flow from the north
through the three day period peaking near 5 mb early Tuesday
morning. There will be weak onshore flow to the east both today
and Wednesday but it will be weakly onshore on Tuesday.

Skies will be mostly clear through the period. The only possible
exceptions will be some night through morning low clouds over two
small areas. The first area will be the western portion of SBA
county where west winds will create back building low clouds in
the Santa Ynez valley which will spread back into the coastal
plain. The second area will be the LGB-LAX area where a weak eddy
may bring some low clouds up from the south in the early mornings.

As mentioned above winds will be the biggest issue over the next
72 hours. The offshore N to S gradients will combine with the
northerly upper level flow to produce periods of advisory level
winds from now until Tuesday afternoon and  beyond into
Wednesday. The winds will peak tonight as the offshore sfc
gradients reach their peak. Due to the diurnal cycle of the
pressure gradients there will be lulls in the winds esp in the
afternoons and early evenings. Please see the product LAXNPWLOX
for all of the wind advisory informations.

Most areas will warm today and Tuesday. Max temps will cool some
on Wednesday as the offshore flow relaxes. Most max temps across
the csts/vlys will be in the 70s with a smattering of lower 80s in
the warmest vly locations. These max temps will be a few degrees
either side of normal.

.LONG TERM (THU-SUN)...29/319 AM.

The EC and GFS both ensembles and deterministic runs are in
decent agreement Thu and Fri. At the upper levels there will be
increasing troffiness which would normally cool things, but
another round of offshore flow from both the north and east will
prevent that and actually warming to the coasts and vlys. On
Friday a reversal to onshore flow will bring increased morning low
clouds and cooling to the csts and vlys.

Mdl agreement wanes sharply for the weekend day 6 and 7 forecast.
The GFS and esp its deterministic run is steadfast in its resolve
to bring a late season storm to the area. The EC and most of its
ensembles just run a broad trof over the area. The GFS ensembles
are pretty varied and do not strongly support the stormy scenario.
At this time the weekend forecast is biased towards the EC
solutions and is dry. There will be a cooling trend each day with
the GFS coming in much cooler than the EC. Again the cooling trend
has been slanted in the EC`s direction. Still need to keep an eye
on the evolution of the GFS`s fcst and if the EC shows any trend
towards a deeper wetter soln as well.
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&&

.AVIATION...29/0638Z.

At 0505Z at KLAX, there was no marine layer. There was a sfc based
inversion with a top of 2400 feet with a temperature of 17 C.

High confidence in TAF package, except for KLAX (30 percent of low
MVFR cigs 13Z-17Z), KLGB (40 percent chc of no cigs) and KSMX (25
percent chc of IFR cigs 12Z-16Z).

KLAX...Moderate confidence in TAF. There is a 30 percent chc of
BKN012 conds 13Z-17Z. No significant easterly wind component is
expected.

KBUR...High confidence in TAF.

&&

.MARINE...28/725 PM.

A very long period of gale force winds is expected to continue
thru at least Tue night for the outer waters. SCA conds are
expected Wed thru Thu, with a 30% chance of gales persisting into
Wed evening.

In the inner waters N of Pt. Sal, SCA level winds are likely thru
Tue night, especially in the afternoon/eve hours. There is a 50%
chance of SCA conds during the afternoon/eve hours Wed/Thu. Seas
are expected to be near SCA levels during the periods of weaker
winds. There is a 25% chance of gale force winds during the
afternoon/eve hours Mon into Tue.

In the SBA Channel, SCA level W-NW winds are expected across
western portions during the afternoon thru late night hours
thru Wed. Winds will likely remain below SCA levels for eastern
portions of the channel through the period.

In the southern inner waters, there is a 20% chance of SCA level
W to NW winds across northwestern portions, mainly from Anacapa
Island to Malibu during the late afternoon thru late evening hours
thru Tue.

Widespread strong to gale force winds will keep dangerous sea
conditions across much of the coastal waters (particularly the
outer waters) thru the middle of the week, with short-period,
steep, and choppy waves. There may be dangerous breaking waves
near west-facing harbors. Mariners should plan accordingly.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
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CA...Wind Advisory now in effect until 3 PM PDT Tuesday for zones
      349-351. (See LAXNPWLOX).
     Wind Advisory in effect until 3 PM PDT Tuesday for zones
      352-353-376-377. (See LAXNPWLOX).
     Wind Advisory remains in effect until 3 PM PDT Tuesday for
      zones 378-381-383. (See LAXNPWLOX).
PZ...Small Craft Advisory in effect until 3 AM PDT Wednesday for
      zone 645. (See LAXMWWLOX).
     Small Craft Advisory in effect until 3 AM PDT Tuesday for
      zone 650. (See LAXMWWLOX).
     Gale Warning in effect until 3 AM PDT Wednesday for zones
      670-673-676. (See LAXMWWLOX).
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&&

$$

PUBLIC...Rorke
AVIATION...Rorke
MARINE...Gomberg/RM
SYNOPSIS...Sirard

weather.gov/losangeles

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