Area Forecast Discussion
Issued by NWS Los Angeles, CA

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000
FXUS66 KLOX 222351
AFDLOX

Area Forecast Discussion...UPDATED
National Weather Service Los Angeles/Oxnard CA
351 PM PST Tue Jan 22 2019

.SYNOPSIS...22/258 PM.

Gusty offshore winds will continue through Wednesday across many
mountain and valley areas and will be strongest during the morning
hours. Temperatures will gradually warm through the week to above
normal as conditions remain dry and sunny.

&&

.SHORT TERM (TDY-FRI)...22/159 PM.

Strong and gusty N to NE winds persisted early this afternoon across
much of the mtns and foothills of L.A./VTU Counties, with some gusty
winds lingering in some of the adjacent valleys, and coastal areas
especially below passes and canyons of the L.A. County coast from
Leo Carillo to the Hollywood Hills. Recent gusts included 60 mph at
at Chilao RAWS, 47 mph at Mill Creek RAWS, and 46 mph at Malibu
Hills RAWS. Many of these areas will continue to have advisory-level
winds through the rest of the afternoon, with Wind Advisories
continuing.

Otherwise, mostly sunny skies with some hi clouds were noted over
the forecast area early this afternoon, with little change
expected thru sunset. Temps will be slightly warmer than
yesterday but remain below normal for the most part. Highs in the
warmest vlys and inland coastal areas should reach the mid to
upper 60s, mainly over VTU/L.A. Counties.

A rather deep upper level trof over the southern Great Basin this
afternoon will gradually move off to the E thru tonight. An upper
level ridge of high pressure well off the CA coast this afternoon
will expand E and into CA tonight thru Wed, with 500 mb heights over
SW CA increasing to near 584 dm on Wed. The upper ridging will
persist along and off the CA coast Wed night thru Fri, altho by Thu
afternoon a weak upper level trof will approach the area from the N.
This weak upper trof should move along the CA/NV border Thu night,
then another sharper upper level trof should move into this area
from the N on Fri.

The strong and gusty N to NE winds will persist through Wed morning
over the mtns, foothills and many vlys of VTU/L.A. Counties, as well
as the L.A. County coast mainly from Malibu to the Hollywood Hills.
Wind Advisories are in effect through Wed morning for all of these
areas. Expected peak wind gusts range from 45 to 55 mph in the mtns
and foothills, and generally 40 to 50 mph elsewhere in the Advisory
areas. Please see the latest Non-Precipitation Weather Message
(LAXNPWLOX) for further details on the ongoing Wind Advisories.

Additional sub-advisory offshore winds will prevail night and
morning hours for many of these areas into Thu, then another round
of advisory level winds can be expected Thu night into Fri morning
as offshore gradients increase substantially (NAM predicted
gradients for LAX-DAG at 12Z Fri is -7.5 mb).

Mostly clear skies with a few hi clouds at times will prevail across
the forecast area tonight through Fri. Temps are forecast to rebound
to near normal to slightly above normal for many areas on Wed. It
will be warmer on Thu and Fri with above normal temps just about
everywhere thanks to offshore flow and warming at 850 mb and in the
boundary layer. Look for highs in the warmest vlys and inland
coastal areas to reach the upper 60s to mid 70s on Wed, and
generally in the 70s on Thu and Fri. Low temps will also be quite
cool again tonight with the coldest sheltered vlys dropping to near
or slightly above freezing, especially over SLO/SBA Counties. It
looks like widespread frost is likely for the SLO County interior
vlys, with freezing conditions in the mid to upper 20s expected for
the Antelope Vly.

.LONG TERM (SAT-TUE)...22/159 PM.

The EC and GFS are in generally good agreement with the synoptic
features over the ern Pac to western U.S. for Sat thru Tue. The
upper level ridging along and off the CA coast will build and
expand into CA over the weekend, with 500 mb heights reaching to
586 dm or so by early Sun. The upper level ridge will then slowly
weaken Mon and Tue while moving back to or just off the CA coast.
Dry weather with mostly offshore flow will prevail across the
forecast area thru the extended period.

Gusty offshore winds night and morning hours can be expected across
swrn CA Sat, with gusts possibly reaching advisory levels in the
wind-prone areas. Sub-advisory offshore flow can be expected into
Sun, with a transition to some weak onshore flow on Mon. Offshore
gradients should increase quickly Mon night into Tue morning, with
support for possible advisory-level or even stronger northeast winds
during that time especially over portions of VTU/L.A. Counties.

Mostly clear skies will continue across the region Sat thru Sun,
then some mid and hi level clouds should move in for Mon with
partly cloudy skies as a whole. Mostly clear skies can then be
expected across the area for Tue.

Temps are forecast to be several degrees above normal for many areas
Sat thru Sun. Temps for Mon should drop to slightly above normal for
the most part, then to near to slightly above normal for Tue. Highs
in the warmest vlys and inland coastal areas should reach the mid
70s to near 80 on Sat, 70s on Sun, and upper 60s to lower 70s Mon
and Tue.

&&

.AVIATION...22/2349Z.

At 00Z, there was no marine layer at KLAX.

VFR conditions are expected through the period. There is a chance
of moderate low-level wind shear and turbulence at terminals
south of Point Conception through 16Z.

KLAX...VFR conditions are expected through the period. There is a
30 percent chance of moderate low-level wind shear and turbulence
between 04Z and 08Z. Any east winds should remain below 7 knots.

KBUR...VFR conditions are expected through the period. There is a
30 percent chance of moderate low-level wind shear and turbulence
between 04Z and 10Z.

&&

.MARINE...22/202 PM.

For the Outer Waters, high confidence in current forecast. Winds
and seas are expected to remain below Small Craft Advisory (SCA)
levels through Saturday.

For the Inner Waters north of Point Sal, high confidence in
current forecast. Winds and seas are expected to remain below SCA
levels through Saturday.

For the Inner Waters south of Point Concpetion, moderate
confidence in current forecast. There is a 50% chance of SCA
level northeast winds again late tonight and Wednesday. Otherwise,
winds and seas are expected to remain below SCA levels through
Friday. On Saturday, there is a 50% chance of SCA level northeast
winds developing again, from Ventura southward.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...Wind Advisory in effect until noon PST Wednesday for zones
      41-44>46-53-54-88-547. (See LAXNPWLOX).
PZ...NONE.

&&

.HAZARD POTENTIAL OUTLOOK (FRI-TUE).

Advisory level north to northeast winds will be possible night
and morning hours Fri and Sat for wind-prone areas of Ventura and
Los Angeles Counties. These areas may have advisory-level to
possible high wind warning level wind gusts Mon night into Tue.

&&

$$

PUBLIC...Sirard
AVIATION...Hall
MARINE...Sweet
BEACHES...Sweet
SYNOPSIS...Kj

weather.gov/losangeles


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