Area Forecast Discussion
Issued by NWS Los Angeles, CA

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FXUS66 KLOX 250033

Area Forecast Discussion...UPDATED
National Weather Service Los Angeles/Oxnard CA
533 PM PDT Sat Mar 24 2018

.SYNOPSIS...24/107 PM.

There is a slight chance of light showers north of Point
Conception this weekend then breezy offshore winds will develop
early in the week. Temperatures will warm to above normal by late
in the week.


.SHORT TERM (SAT-TUE)...24/132 PM.

Upper level trough will prevail across California this weekend
with onshore flow near the surface. Most of the energy with
this current system will pass to our north with scattered showers
detected this afternoon across Monterey county northward and
extending offshore. A weakening frontal system will bring isolated
showers to SLO county through this evening. There will be some
upslope flow and associated moisture that will also bring
a 20-30 percent chance of showers to the north facing mountain
slopes as well as the interior valleys of SLO/SBA counties tonight
into Sunday morning (with best chance near the Kern county line).
Snow levels are expected to fall to between 3500 and 4000 feet
across interior sections later tonight, bringing a threat of
brief snow showers to Interstate 5 near the Grapevine overnight
into Sunday morning. For most of the region, this upper level
trough will usher in cooler and windy conditions this weekend,
with winds potentially approaching advisory levels in the Antelope
Valley on Sunday.

Behind this upper level trough, gusty northwest to north winds
will develop across typical north facing passes and canyons
including the Interstate 5 corridor and Santa Ynez mountains/SBA
south coast. Advisory level winds will be possible in these
areas with gusts generally ranging between 35 and 45 mph.
By late Monday night into Tuesday, the upper level flow shifts
to the northeast for a return of gusty Santa Ana winds to
portions of LA/Ventura counties. While the surface gradient
remains modest (with LAX-Daggett peaking at around -3 mb on
Tuesday morning), there is a fairly good burst of upper level
wind support (with NAM 850 mb winds expected to range between
35 and 45 knots). As a result, could see some northeast winds
reaching advisory levels in the mountains of LA/Ventura counties
during this period, possibly extending into some of the valleys.
The offshore flow will bring noticeably warmer temperatures
on Tuesday with highs climbing well into the 70s.

.LONG TERM (WED-SAT)...24/128 PM.

Offshore flow will likely continue Wednesday through Friday
maintaining warm temperatures across the area. In fact,
some of our warmer valley areas could reach 80 degrees.
By next weekend, long range models in agreement that
onshore flow will most likely return to the area bringing
a cooling trend. And looking down the horizon, both
the ECMWF and GFS models not showing any precipitation
chances during the 3-10 day period.



At 00Z, there was a weak marine inversion around 500 feet KLAX.

Moderate confidence in the current forecast. There is a chance of
MVFR conditions at Los Angeles County terminals and terminals
north of Point Conception. Periods of moderate wind shear and
turbulence are possible through 16Z at KSBA.

KLAX...There is a 50 percent chance of ceilings less than 5000
feet between 04Z and 20Z. Any north winds that develop should
remain less than 10 knots through Sunday evening, then north winds
could increase above 10 knots on Sunday night.

KBUR...There is a 50 percent chance of ceilings less than 5000
feet between 04Z and 20Z.


.MARINE...24/119 PM.

Generally good confidence in the current forecast. For the outer
waters, Small Craft Advisory (SCA) winds will affect PZZ676 at
least through Monday morning, with SCA winds for PZZ670 and PZZ673
Sun thru at least Tue morning. There will then be a 30%-40%
chance of Gale Warning wind gusts for these zones Mon afternoon
and evening, followed by a 50%-60% chance of SCA winds late Mon
night thru Tue morning.

For the inner waters zones N of Point Conception, winds are
expected to increase to SCA levels Sun night and persist at times
thru Mon evening. For the inner waters S of Point Conception, SCA
winds will prevail tonight then again Sun night into Mon night,
altho there is a 30%-40% chance of Gale Warning gusts at times
during the period. Gusty offshore winds near SCA levels can be
expected especially near shore from near Point Mugu to Santa
Monica late Mon night into Tue morning. PZZ655 will also have a
30% chance of SCA wind gusts Tue evening.


PZ...Small Craft Advisory in effect until 3 AM PDT Sunday for
      zones 650-655. (See LAXMWWLOX).
     Small Craft Advisory in effect until 9 AM PDT Monday for
      zones 670-673-676. (See LAXMWWLOX).



Advisory level Santa Ana winds are possible late Monday night into
Tuesday across the mountains and valleys of Los Angeles and
Ventura counties.



SYNOPSIS...Kj is the U.S. government's official web portal to all federal, state and local government web resources and services.