Wind Advisory 34, NWS Los Angeles, CA

Area Forecast Discussion
National Weather Service Los Angeles/Oxnard CA
143 PM PDT Mon Apr 8 2019

.SYNOPSIS...08/128 PM.

A weak front may bring showers to the Ventura mountains on
Tuesday. Elsewhere, it will be partly cloudy and cooler, with
widespread strong winds that will continue into Wednesday. Dry
weather is then expected through the weekend, except for a chance
of showers Friday.

&&

.SHORT TERM (TDY-THU)...08/132 PM.

A trough moving through the West Coast today will have a few
impacts locally the next couple days. We're already seeing some
high clouds moving through the area today but not thick enough to
prevent temps from jumping into the 90s in parts of the LA/Ventura
valleys thanks to continued light offshore flow and a very warm
air mass in place. We'll see another round of low grade advisory
level Sundowners tonight in srn SB County and local gusts to 40-45
mph in the I5 corridor.

The bigger impacts will come Tuesday and Tuesday night with and
following the trough passage through the area. The biggest being
the increase in speed and areal coverage of the northerly winds as
winds aloft pick up to 50-60kt around 850mb. This will force winds
down to lower elevations resulting in at least advisory level
wind gusts across much of SB/Ventura/LA County coasts/valleys and
60+ mph warning level gusts in the mountains, especially above
Montecito and in the I5 corridor. Winds expected to peak in the
late afternoon and evening in most areas.

There isn't a lot of moisture with this system as it's taking a
more over-land trajectory but the strong northerly flow will push
what little moisture there is up the north facing slopes near the
Kern County line generating showers stretching from southeast SLO
County to extreme northwest LA County near the I5 corridor. Total
amounts between a quarter to a half inch in the mountain areas
close to the Kern County line. Snow levels lowering to around
6000' but only an inch or two of snow at most.

Lastly temps will cool by as much as 10-15 degrees as onshore flow
returns and cool air moves in with the trough. Still looking at
highs in the 70s most areas south of Pt Conception and 60s in the
north.

Northerly flow will persist Wednesday and Thursday, but not quite
as strong in most areas so it's likely wind advisories will need
to be extended beyond their current expiration time. Not much
change in temperatures.

.LONG TERM (FRI-MON)...08/141 PM.

The deterministic GFS and ECMWF continue to hold onto their
respective solutions for Friday with the GFS more east and drier
than the ECMWF. Neither solution would bring much if any precip to
the area but the ECMWF and to a lesser degree the ensembles certainly
show enough cold air and energy aloft to keep a threat of
precipitation in most areas Friday. If the deterministic solutions
are correct precip would remain mainly just near the north facing
mountains, similar to Tuesday's scenario. Will keep in some low
pops in other areas in case the system does track farther west.
Temps will definitely be cooler with highs mostly 60s to low 70s.
Onshore flow will continue through early next week so while it
should remain dry temps will be near to slightly below seasonal
norms.

&&

.AVIATION...08/1749Z.

At 1631Z at KLAX...The marine layer depth was 500 feet, with a
weak inversion topping out at 900 feet with a temperature of 22
degrees C.

Hi confidence in the 18Z TAFs with VFR conditions expected at all
the airfields through early Tue morning. However, there is a 20
percent chance of MVFR conds for coastal TAF sites N of Point
Conception after 08z Tue morning.

KLAX...Hi confidence in the 18Z TAF with VFR conditions expected
through early Tue morning.

KBUR...Hi confidence in the 18Z TAF with VFR conditions expected
through early Tue morning.

&&

.MARINE...08/902 AM.

For the Outer Waters... Small Craft Advisory (SCA) conditions will
continue through this afternoon in the central and southern outer
waters and through late this evening in the northern outer waters
then there is a eighty percent chance of Gale force winds through
early Thursday morning. The stronger winds will develop initially
across the southern outer waters south of Point Conception this
evening, then will overspread the entire outer waters by Tuesday
morning. Northwest wind gusts expected to reach 40 to 45 knots or
more at times on Tuesday through Tuesday night.

For the Inner Waters north of Point Sal... Conditions should
remain below SCA levels through this evening, then rapidly
increase to Gale force winds tonight. There is a 60 percent
chance for Gale force winds to develop tonight and persist through
Tuesday evening with a 30 percent chance to continue into early
Wednesday morning. Otherwise SCA level winds will continue each
afternoon and evening hours through Friday evening. Winds will be
strongest in the western portion.

For the Inner Waters south of Point Conception... SCA conditions
across the eastern Santa Barbara Channel and NW portion of the
southern inner waters will develop this afternoon and continue
through the overnight hours. There is a 70% chance for Gale force
winds across the western portions by Tuesday morning, then
overspreading much of the inner waters by Tuesday afternoon
through late Tuesday evening. Otherwise SCA level winds will
continue through Friday, with local gusts to 35 kt across the NW
portion of the eastern SBA Channel.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
PZ...Gale Warning in effect from 3 AM to 9 PM PDT Tuesday for zone
      645. (See LAXMWWLOX).
     Small Craft Advisory in effect until 9 AM PDT Tuesday for
      zones 650-655. (See LAXMWWLOX).
     Gale Watch in effect from Tuesday morning through Tuesday
      evening for zones 650-655. (See LAXMWWLOX).
     Small Craft Advisory in effect until 3 AM PDT Tuesday for
      zone 670. (See LAXMWWLOX).
     Gale Warning in effect from 3 AM Tuesday to 3 AM PDT Thursday
      for zone 670. (See LAXMWWLOX).
     Small Craft Advisory in effect until 3 PM PDT this afternoon
      for zones 673-676. (See LAXMWWLOX).
     Gale Warning in effect until 3 AM PDT Thursday for zones
      673-676. (See LAXMWWLOX).

&&

.HAZARD POTENTIAL OUTLOOK (THU-MON).

Gusty northerly winds are expected through early Thursday,
especially for the mountains and southern Santa Barbara County.
High surf is possible on Central Coast beaches Thursday through
Friday.

&&

PUBLIC...MW
AVIATION...Kaplan/Sweet
MARINE...Kaplan/Sweet
BEACHES...Kaplan
SYNOPSIS...B

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