High Wind Watch 3, NWS Los Angeles, CA

Area Forecast Discussion
National Weather Service Los Angeles/Oxnard CA
148 PM PDT Fri Oct 18 2019

.SYNOPSIS...18/133 PM.

Gusty north to northwest winds are expected to continue tonight
through Sunday, the with strongest winds expected Saturday night.
Weak Santa Ana winds are expected Sunday night through Tuesday
with temperatures warming above normal.

&&

.SHORT TERM (TDY-MON)...18/146 PM.

Wind continues to be the primary weather concern over the next few
days. We had isolated warning level wind gusts early this morning
in the I5 corridor and in srn SB County. The parameters aren't
quite as favorable tonight as upper support is weaker due to the
trough having moved to the east. Still pretty impressive surface
gradients though and enough to keep wind advisories going for srn
SB County and the I5 corridor.

Pretty similar day Saturday as today overall with temps within a
few degrees of today. We'll be transitioning to another strong
northerly wind event later Saturday into Sunday so we'll likely
see winds increasing in strength in many areas by afternoon and
evening. Then overnight into Sunday the upper support from the
trough passage will kick in along with some cold air advection to
push wind speeds up to at least Thursday night's levels and likely
a tad stronger. Models still showing a 6-7mb gradient from BFL
early Sunday morning which is 1-2mb stronger than what happened
earlier this morning. For this reason a high wind watch will be
issued for all the mountains, including the Santa Monicas, as well
as the Santa Clarita Valley Saturday night into Sunday morning.
Advisory level winds expected to develop in many other areas
including the LA/Ventura Valleys and even parts of the LA Coast,
especially from Malibu to the Hollywood Hills and down through the
south bay area. Highs Sunday expected to rise 3-6 degrees in most
areas.

Sunday afternoon into Monday we'll be transitioning to a low
grade Santa Ana as the trough moves east and winds take on a more
easterly component. Upper support drops off and the air mass warms
as the ridge starts building in from the west but there will be
just enough surface gradient and winds up to 850 mb to maintain
gusty (though mostly sub-advisory level) Santa Ana winds across
LA/Ventura Counties as well as the Santa Lucia's along the Central
Coast. Temps will be warming up quite a bit as well with highs
jumping up into the lower 90s for inland coastal areas and
valleys.

.LONG TERM (TUE-FRI)...18/143 PM.

Tuesday is expected to be the warmest day for coast/valleys as
gradients will start trending onshore later in the day into
Wednesday. Some light offshore breezes possible, mainly in the
mountains, but otherwise just hot and dry.

The ridge will start to shift back to the west as a trough drops
out of Canada and into the northern Rockies and Great Basin.
Gradients will turn onshore Wednesday into Thursday with high
temps dropping several degrees across coast/valleys, though still
a few degrees above normal. The Pacific ridge is expected to
expand east again over California and gradients will again turn
offshore following the trough passage through the Great Basin and
into the Plains. The GFS has fluctuated a fair amount on this but
the ECMWF has been consistent and now more ensemble members are
supporting at least an advisory level Santa Ana wind event Friday
into next weekend and likely very warm and dry.

&&

.AVIATION...18/1742Z.

At 17Z at KLAX, there was no marine inversion. There was a
shallow moist layer around 1500 feet deep.

VFR conditions with clear skies expected across the majority of
terminals. The only exception will be scattered MVFR clouds across
the LA Basin after 09Z Saturday and could impact KLGB or KLAX by
sunrise. Gusty N to NW winds will affect the mountains, the Santa
Clarita Valley and the south coast of SBA County through Saturday,
with associated local LLWS and moderate UDDF.

KLAX...High confidence in the 18Z TAF. VFR conds expected through
the period. There is a 10% chance of MVFR cigs between 12Z and
17Z Saturday morning. East winds will remain below 8 kts between
10-17Z tomorrow.

KBUR...High confidence in the 18Z TAF with VFR conds expected
through the period.

&&

.MARINE...18/946 AM.

Outer Waters...Moderate to high confidence. Gale force winds were
widespread across most of the outer waters, but dropping to small
craft advisory levels for northern waters. Across the remainder
of the outer waters, Gale force winds will likely continue through
late tonight. Thereafter, winds will likely remain at or above
Small Craft Advisory (SCA) Levels through Tue, except possibly
just Mon for the southernmost areas.

Inner Waters N of Pt. Sal...Moderate to high confidence. Seas will
be near to slightly above SCA levels this morning. NW winds will
increase to SCA levels this afternoon and continue through late
tonight. SCA level NW winds are likely during the afternoon and
evening hours Sat, and there is a 40-50% chance of SCA level NW
winds Sun afternoon and evening.

Santa Barbara Channel...Moderate confidence. SCA level W to NW
winds are expected across western portions through late tonight.
There is a 20% chance that SCA level winds will affect eastern
areas this afternoon and evening. SCA level W to NW winds are
likely across western portions again Sat afternoon and possibly
into the evening.

For the inner waters south of Pt. Mugu...Moderate confidence.
Winds and seas are expected to remain below SCA levels through
Tue. However, there is a 20% chance of SCA level W-NW winds
across western portions this afternoon and evening. There is a
20-30% chance of SCA level N to NE winds near shore from Pt. Mugu
to Santa Monica Sunday morning and Monday morning.

Rather hazardous short period seas are expected across all of the
waters during much of the forecast period due to strong winds and
large, steep seas, combined with a long period NW swell.

&&

.BEACHES...18/136 PM.

Surf will continue to build from 9 to 12 feet on west-facing
beaches of the central coast with local sets to 15 feet possible.
Surf will gradually subside early Saturday morning. There is a
chance that the surf will remain near or above the high surf
threshold of 10 feet through Saturday evening.

South of Point Conception, the northwesterly component of the
swell means that less energy will make it to shore. However, the
west facing beaches of Ventura and Los Angeles Counties could have
surf of 3 to 6 feet tonight through Sunday.

&&

.FIRE WEATHER...18/948 AM.

Northerly winds will persist across many portions of Southwest California
today through Sunday, with peak gusts between 30 and 50 mph common.
These winds will affect southern and central Santa Barbara County, the Santa
Clarita Valley, San Fernando Valley, Santa Monica Mountains and
Central Coast. The strongest northerly winds will be over the entire
Santa Ynez Range and the Tejon Pass Saturday night into Sunday, when
isolated gusts of 60 to 70 mph are likely (especially near Montecito Hills
and Whitaker Peak).  While humidities will generally remain above 20 percent
across the higher mountains (where winds will be strongest) with moderate
recoveries at night, humidities will generally lower to between 10 and 20
percent across downslope areas each day through Sunday. The combination of
moderate to locally strong sundowner winds combined with low humidities and
dry fuels has resulted in the issuance of the Red Flag Warning for the
Santa Barbara south coast and mountains later this afternoon through
Sunday evening. There will be widespread elevated to brief critical fire weather
conditions for many other portions of Southwest California through Sunday due
to the northerly winds and areas of low humidities.

The winds are  expected to shift to northeasterly Sunday night into Monday.
These winds look weaker than previous projections, and humidities look
slightly higher. Elevated fire weather conditions will continue into
Monday due to the offshore winds, lingering low humidities, and
warm conditions, with highs between 85 and 95 degrees in warmer coastal
and valley areas.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...High Surf Advisory in effect until 8 AM PDT Saturday for
      zones 34-35. (See LAXCFWLOX).
     Wind Advisory in effect until 11 AM PDT Sunday for zone 39. (See LAXNPWLOX).
     Wind Advisory in effect from 6 PM Saturday to 11 AM PDT
      Sunday for zones 41-44-45-547. (See LAXNPWLOX).
     High Wind Watch in effect from Saturday evening through
      Sunday morning for zones 46-52>54-88. (See LAXNPWLOX).
     Wind Advisory in effect until 6 PM PDT Saturday for zones
      52-54. (See LAXNPWLOX).
     Wind Advisory in effect from 1 PM Saturday to 3 AM PDT Sunday
      for zone 59. (See LAXNPWLOX).
     Red Flag Warning in effect until 10 PM PDT Sunday for zones
      239-252. (See LAXRFWLOX).
PZ...Small Craft Advisory in effect until 3 AM PDT Saturday for
      zones 645-650. (See LAXMWWLOX).
     Small Craft Advisory in effect until 3 AM PDT Monday for zone
      670. (See LAXMWWLOX).
     Gale Warning in effect until 3 AM PDT Saturday for zones
      673-676. (See LAXMWWLOX).

&&

.HAZARD POTENTIAL OUTLOOK (MON-FRI).

Elevated to briefly critical fire weather conditions possible
over Los Angeles and Ventura Counties Monday due to hot and dry
conditions and locally breezy Santa Ana winds. Critical fire
weather conditions possible later next week as Santa Ana winds
are expected to return.

&&

PUBLIC...MW
AVIATION...EB
MARINE...EB/DB
BEACHES...EB
FIRE...Gomberg
SYNOPSIS...Stewart

weather.gov/losangeles

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
1127 AM PDT FRI OCT 18 2019

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0505 AM     NON-TSTM WND DMG 2 WSW BURBANK           34.18N 118.35W
10/18/2019                   LOS ANGELES        CA   PUBLIC

            MULTIPLE UPROOTED TREES NEAR HOLLYWOOD WAY
            AND WYOMING AVE IN BURBANK.

&&

KS