Area Forecast Discussion
Issued by NWS Los Angeles, CA

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000
FXUS66 KLOX 220010
AFDLOX

Area Forecast Discussion
National Weather Service Los Angeles/Oxnard CA
410 PM PST Mon Jan 21 2019

.SYNOPSIS...21/245 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 as
conditions remain dry.

&&

.SHORT TERM (TDY-THU)...21/203 PM.

Strong and gusty NW to N winds persisted over much of the mtns and
foothills as well as across the Antelope Vly early this afternoon.
Recent highest gusts include 53 mph at the Saugus RAWS and 49 mph at
the Camp 9 RAWS. For the VTU/L.A. County vlys, there were some gusts
over 35 mph noted such as 40 mph at Whittier Hills. These winds will
persist thru the rest of the afternoon, especially in the deserts,
mtns and foothills, with widespread Wind Advisories continuing for
much of the area.

Partly cloudy skies were noted over portions of SLO/SBA Counties and
along the N mtn slopes early this afternoon. Otherwise, mostly
sunny skies continued with the breezy and cool conditions. Highs
this afternoon will be in the mid 50s to mid 60s for much of the
coast and vlys, and upper 40s to low 50s in the Antelope Vly.

A rather potent inside slider upper level trof was over eastern CA
this afternoon will gradually move off to the SE thru tonight. An
upper level ridge of high pressure will build off the CA coast late
tonight and Tue then edge closer to the coast 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 and
Thu, altho by Thu afternoon a weak upper level trof will approach
the area from the N.

The strong and gusty NW to N winds will transition to N to NE
tonight and Tue and affect 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. Additional rounds of gusty NE
winds are expected in these areas Tue night into Wed morning, with
Wind Advisories in effect through Wed morning. For the SBA County
S coast and mtns, gusty N winds can be expected through Tue
morning, especially below and thru the passes and canyons, where
Wind Advisories are in effect thru the period. The Antelope Vly
can also expect strong and gusty W to NW winds thru this evening,
where Wind Advisories are in affect through 9 PM. Expected wind
gusts range from 45 to 55 mph in the deserts, mtns and foothills,
and generally 35 to 45 mph elsewhere in the Advisory areas. Please
see the latest Non-Precipitation Weather Message (LAXNPWLOX) for
further details on the ongoing Wind Advisories.

There should be residual clouds and isolated snow showers on the N
mtns slopes through tonight, otherwise mostly clear skies will
prevail across the forecast area tonight through Thu. Temps are
forecast to still be only near normal to slightly below normal on
Tue, then rebound to near normal to slightly above normal for many
areas on Wed. It will be warmest on Thursday 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 mid to upper 60s on Tue, the upper
60s to lower 70s on Wed, and generally in the 70s to near 80 on Thu.
Low temps will also be quite cool the next couple of nights with the
coldest sheltered vlys dropping to near or slightly above freezing.
However, 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 (FRI-MON)...21/205 PM.

The EC and GFS are in generally good agreement with the synoptic
features over the ern Pac to western U.S. for Fri thru Sun. On Mon,
the EC dives an upper level trof deep into the Great Basin, with
srn CA under a broad northerly flow aloft and lowering 500 mb
heights. The GFS, however, keeps weakening upper level ridging
over CA Sun night and Mon. Will lean more toward the GFS for Mon,
with milder temps continuing. At any rate, both the EC and GFS
bring dry weather to the forecast area thru the extended period.

Gusty offshore winds night and morning hours can be expected across
swrn CA Fri and Sat, with gusts possibly reaching advisory levels in
the wind-prone areas. Weaker offshore flow can be expected into Sun,
with a transition to some onshore flow on Mon. Mostly clear skies
will prevail across the region Fri thru Sun, then some mid and hi
level clouds could move in for Mon with partly cloudy skies as a
whole.

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

&&

.AVIATION...22/0008Z.

At 2355Z, there was no marine inversion at KLAX.

Moderate confidence in 00Z TAF package. High confidence in VFR
sky conditions for all sites through the TAF period. Low to
moderate confidence in wind forecast due to some uncertainty of
the timing of changes in strength/direction. With strong upper
level wind support tonight through Tuesday morning, there will be
the potential for strong uddfs and llws for TAF sites south of
Point Conception.

KLAX...Moderate confidence in 00Z TAF. High confidence in VFR
conditions through TAF period. Moderate confidence in timing of
changes in wind strength/direction. Northerly cross wind gusts
of 15-25 knots likely sometime between 03Z-12Z tonight. After 12z,
there is a chance of NE winds but mostly likely remaining below 10
knots, however there is possibility of LLWS with uddfs during the
morning hours.

KBUR...Moderate confidence in 00Z TAF. High confidence in VFR
conditions through TAF period. Moderate confidence in timing of
changes in wind strength/direction. Northwest-north winds likely
gusting between 20 and 30 knots through tonight, shifting to the
northeast on Tuesday morning. There is the potential for strong
uddfs and LLWS during this period due to strengthening upper level
wind support.

&&

.MARINE...21/153 PM.

For the Outer Waters, moderate confidence in current forecast.
Strong Small Craft Advisory (SCA) level northwest winds will
continue through tonight with a 20% chance of Gale force gusts. On
Tuesday, there is a 30% chance of SCA level winds then winds and
seas are expected to remain below SCA levels Wednesday through
Friday.

For the Inner Waters north of Point Sal, high confidence in
current forecast. SCA level northwest winds will continue through
tonight. For Tuesday through Friday, winds and seas are expected
to remain below SCA levels.

For the Inner Waters south of Point Conception, moderate
confidence in current forecast. Extended the SCA right through
tonight and into Tuesday as the strong northwest winds shift to
northeast Tuesday morning and are likely to be above SCA speeds
again Tuesday morning, if not right through the night.

&&

.BEACHES...21/1137 AM.

A new west to northwest swell will move into the coastal waters
today. These swells will produce elevated surf and strong rip
currents on west-facing beaches through this afternoon, before
very slowly decreasing tonight and Tuesday. Large astronomical
high tides are also be expected each morning through this time,
peaking today. Due to the higher than normal tides and elevated
surf, there could be minor coastal flooding near the times of the
morning high tide each day. As a result of the elevated surf and
potential for minor coastal flooding, a Beach Hazards Statement is
in effect for all west facing beaches through Tuesday, except
southern Santa Barbara county, which expires this afternoon.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...Beach Hazards Statement in effect through Tuesday morning for
      zones 34-35-40-41-87. (See LAXCFWLOX).
     Wind Advisory in effect until 10 AM PST Tuesday for zones
      39-52. (See LAXNPWLOX).
     Wind Advisory in effect until noon PST Wednesday for zones
      41-44>46-53-54-88-547. (See LAXNPWLOX).
     Wind Advisory in effect until 9 PM PST this evening for zone
      59. (See LAXNPWLOX).
PZ...Small Craft Advisory in effect until 3 AM PST Tuesday for
      zones 645-670-673-676. (See LAXMWWLOX).
     Small Craft Advisory in effect until 1 PM PST Tuesday for
      zones 650-655. (See LAXMWWLOX).

&&

.HAZARD POTENTIAL OUTLOOK (THU-MON).

Advisory level north to northeast winds will be possible night
and morning hours Thursday and Friday for wind-prone areas of
Ventura and Los Angeles Counties.

&&

$$

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

weather.gov/losangeles


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