FXUS66 KLOX 111726

Area Forecast Discussion
National Weather Service Los Angeles/Oxnard CA
926 AM PST Mon Dec 11 2023

.SYNOPSIS...11/914 AM.

Offshore flow will continue most of the week, with gusty north to
northeast winds at times, especially Tuesday night through early
Thursday. Dry weather is expected through at least Saturday, with
above normal temperatures during the days. Nights will be colder
than normal, at least in wind-sheltered areas. A storm system
moving into the eastern Pacific may bring rain to the region as
early as very late this weekend, but more likely next week.


.SHORT TERM (TDY-WED)...11/925 AM.


Overall a very quiet week of weather expected in southwest
California. Offshore flow continues to weaken today with only
light northeast breezes this morning turning to light sea breezes
this afternoon. There will be some passing high clouds through the
day but plenty of sunshine today and the rest of the week. May get
some marine layer clouds near the LA/Ventura coastal areas the
next couple nights as well. Temperatures expected to cool across
most areas today and Tuesday, though likely a little warmer in the
Antelope Valley.

A weak trough over WA this morning will develop into closed upper
low near Vegas Wednesday morning and this will provide some
support for offshore winds.

***From Previous Discussion***

The upper low will become more compact and drop southward into
northwestern Arizona late Tue night/Wed morning, and a ridge will
amplify across the eastern Pacific. The will cause an increasing
gradient of the 500 mb height pattern across the region, with some
increase in northerly winds aloft. Low level gradients will
become more offshore again by Wed morning. Although the KLAX to
KDAG gradients will generally only be between 3 and 4 mb offshore
Wed morning, there will be a modest increase in upper support and
some cold air advection Tue night. This should produce an uptick
in northerly winds across SBA County and maybe through the I-5
Corridor Tue night. Then, as the low level flow turns more NE,
there may be an increase in NE winds across the mtns/valleys of
L.A./VTU Counties with winds possibly pushing into the VTU County
coast, and to the Malibu Coast. Winds could get close to advisory
level in some areas late Tue night/Wed, but at this time, it does
not look as though it will be nearly as windy as it was on Sat.

Max temps may be up a couple of degrees west of the mtns Wed due
to offshore flow and some height rises, but low level cold
advection may bring some cooling to the mtns and the Antelope
Valley. Tue night will be a chilly night in wind sheltered
locations across the interior, with some freezes possible in the
normally colder valley locations of SLO and SBA Counties.

.LONG TERM (THU-SUN)...11/453 AM.

The upper ridge will move into CA Thu, causing heights to rise.
Offshore gradients may a bit sharper Thu morning, but upper
support will wane, so expect gusty NE winds across L.A./Ventura
Counties to be below advisory levels. Expect some warming in most
areas Thu, with max temps 5 to 10 degrees above normal. Max temps
in some of the warmer locations in the valleys and in interior
sections of the coastal plain may approach 80 degrees Thu.

A large upper low will develop in the eastern Pacific Thu night
and Fri, then drop slowly southward while making very little
eastward progress thru Sat. As it drops southward, the ridge over
the area will linger, and heights may even rise a bit Fri.
Gradients will remain offshore thru Sat, and while there may be
some gusty NE winds at times, do not expect any advisory level
wind Thu night thru Sat. Some high clouds may move into the area
late in the week and over the weekend, but with the offshore flow,
do not expect any low clouds to form. Max temps will likely remain
several degrees above normal Fri and Sat. With dry conditions
continuing, it should be rather cold each night Wed night thru Fri
night in wind-sheltered locations across the interior.

The upper low will begin to push toward the West Coast Sun. Clouds
should increase across the region, and there is a slight chance of
rain, especially across northern areas late in the day. However,
with slow moving systems that are cutoff from the main flow,
there is a chance that the low may linger off the coast longer
than expected. Therefore, there will likely be a better chance of
any rain beginning some time early next week.



Around 0930Z, there was no marine layer depth at KLAX. There was a
surface-based inversion up to around 700 feet with a temperatures
near 21 degrees Celsius.

High confidence in VFR conditions at all terminals through 03Z
Tuesday, then moderate confidence for coastal terminals
thereafter. There is a low-to-moderate chance of VLIFR to LIFR
conditions after 03Z Tuesday. There is a low chance of moderate
low-level wind shear and turbulence through 16Z.

KLAX...VFR conditions are expected through at least 03Z Tuesday,
then there is a 30 percent chance of VLIFR to LIFR conditions.
There is a less than 10 percent chance of moderate low-level wind
shear and turbulence through 16Z. Any easterly winds will likely
remain less than 7 knots.

KBUR...VFR conditions are expected through the period. There is a
less than 10 percent chance of moderate low-level wind shear and
turbulence through 16Z.


.MARINE...11/853 AM.

For the waters southwest through northwest of the Channel Islands
and the nearshore waters along the Central Coast, northwest winds
will continue to increase Small Craft Advisory (SCA) levels
through this afternoon. There is a 30-50 percent chance that winds
will drop below SCA levels late tonight and early Tuesday
morning. Winds and seas will drop below SCA levels between late
Tuesday night and early Wednesday morning, then remaining below
SCA levels through the remainder of the week.

Inside the southern California bight, there is a 30-50 percent
chance of SCA level northwest to north winds each evening across
the western and central Santa Barbara Channel through Wednesday
evening. Farther to the south between Rincon Point and Pacific
Palisades, there is 30-40 percent chance of SCA level northeast
winds Wednesday morning, and again Wednesday night through
Thursday morning.


PZ...Small Craft Advisory in effect until 9 PM PST this evening
      for zone 645. (See LAXMWWLOX).
     Small Craft Advisory in effect until 3 AM PST Wednesday for
      zones 670-673. (See LAXMWWLOX).
     Small Craft Advisory in effect from 3 PM this afternoon to 9
      PM PST Tuesday for zone 676. (See LAXMWWLOX).





Experimental Graphical Hazardous Weather Outlook at: