Area Forecast Discussion
Issued by NWS Los Angeles, CA

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000
FXUS66 KLOX 240628
AFDLOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
1128 PM PDT Sun Apr 23 2017

.SYNOPSIS...
A low early this week will create an overnight marine layer...normal
temperatures and gusty winds in the mountains...deserts and central
coast. Around midweek we will have a high to the west...an a low to
our east for fair skies...gusty winds and above normal temperatures
into the weekend.

&&

.SHORT TERM...(SUN-WED)

Long duration of moderate to strong northwest to north winds
through much of the week. Wind advisories already in effect for
the mountains, Antelope Valley, Central Coast, and SBA south
coast where gusts between 40 and 55 mph will be common at times
through Tuesday. This evening, Santa Barbara-Santa Maria pressure
gradient already at -4.8 mb, with strongest winds currently
focused across the passes and canyons from Gaviota to Goleta.
Overnight, should see the gusty northerly winds strengthen further
eastward across the foothills above Montecito. The strongest
winds so far have been at Refugio hills with a peak gust of 52
mph. Other short term weather concern tonight will be return of
marine layer clouds across portion of the coast and coastal
valleys. Satellite imagery showing low clouds forming off the
coast of Orange/San Diego counties this evening. With an eddy
circulation in place, look for these low clouds to spread
northwestward across the LA basin and Ventura coast overnight
into Monday morning.

Upper level wind support will be increasing on Monday night.
Then by Tuesday night, appears that strong upper level wind
support will be in better phase with tightening northerly pressure
gradient, which could translate into a stronger and more
widespread northerly wind event across the forecast area. 00z
NAM showing potential for a -7 mb pressure gradient between
SBA-Bakersfield and LAX-Bakersfield late Tuesday night. This
could translate into warning level wind gusts of 60 mph or greater
for the LA county mountains (I-5 corridor section) as well as the
Santa Ynez mountains (especially near Montecito Hills) Tuesday
night into Wednesday.

*** From previous discussion ***

Afternoon temperatures will continue to cool during the next few
days and will be near normal by Tuesday. It will be dry in most
locations during the period with the possible exception of the
north slopes of the Los Angeles County mountains near the Kern
County line Monday night and Tuesday morning where a northerly
flow will pile up clouds and create a slight chance of a shower.

.LONG TERM...(THU-SUN)

A lingering upper level trough over the western states will keep a
moderately strong northwest to northerly flow across southwestern
California through Thursday. Wind advisory level gusts may
continue through the period for the northwest wind prone areas...
especially across southern Santa Barbara County... the Central
Coast... The Antelope Valley... and the mountains. Northerly flow
will bring some downslope warming to coastal and valley areas by
late in the week and temperatures may rise toward ninety degrees
by the weekend. This would result in another hot weekend with
afternoon temperatures up to ten degrees above normal.

&&

.AVIATION...24/0625Z...

At 06Z, the marine inversion at KLAX was based at 1300 feet. The
top of the inversion was 2500 feet with a temp of 16C.

Expect stratus with MVFR conds across coastal sections of L.A.
County and the San Gabriel Valley. There could be some IFR conds
in the San Gabriel Valley. There is a slight chance of stratus
with IFR conds across coastal sections of VTU County and on the
Central Coast.

There will be areas of gusty nw winds through the pd across the I5
Corridor, southern SBA County, the Antelope Valley and on the
Central Coast. Expect some LLWS and mdt UDDF through and below
passes and canyons, especially near KSBA.

KLAX...Moderate confidence in the 06Z TAF. There is a 20-30%
chance that conds will remain VFR through the pd. There is a 20
percent chance that conds will be IFR from 12Z-16Z.

KBUR...High confidence in 06Z TAF with VFR conds expected thru the
pd. There is a 20% chance of MVFR/IFR CIGs between 12Z and 16Z.

&&

.MARINE...23/800 PM...

For the Outer Waters, high confidence in current forecast. Strong
northwest winds are anticipated to continue through the week.
Currently, a Gale Warning is in effect through Monday night. Gale
force winds will likely continue through Friday.

For the Inner Waters, moderate to high confidence in current
forecast. For the waters north of Point Sal, strong Small Craft
Advisory (SCA) level winds are expected each afternoon/evening
through Friday with a 30% chance of Gale force winds developing
Tuesday through Friday. For the waters south of Point Conception,
SCA level winds are expected each afternoon and evening through
Friday with the strongest winds across the western Santa Barbara
Channel. There will be a 30% chance of Gale force winds Tuesday
through Friday across western sections.

Due to strong winds throughout the waters, seas will be very
choppy this week, making for hazardous boating conditions through
the week.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...High Surf Advisory in effect until 10 PM PDT Monday for zones
      34-35-40-41-87. (See LAXCFWLOX).
     Wind Advisory in effect until 3 AM PDT Tuesday for zones
      34-35. (See LAXNPWLOX).
     Wind Advisory in effect until 3 AM PDT Wednesday for zones
      39-52>54-59. (See LAXNPWLOX).
PZ...Small Craft Advisory in effect until 3 AM PDT Monday for
      zones 645-650-655. (See LAXMWWLOX).
     Gale Warning in effect until 3 AM PDT Tuesday for zones
      670-673-676. (See LAXMWWLOX).

&&

.HAZARD POTENTIAL OUTLOOK...(WED-SUN)
Very gusty north to northwest winds are expected across southern
Santa Barbara County, the Central Coast, the I-5 corridor, and
the Antelope Valley. Advisory level winds expected at times and
possibly exceeding warning levels, especially in the I-5 corridor
and southern SB County Wednesday and Thursday.

&&

$$

PUBLIC...Gomberg/KJ
AVIATION...DB
MARINE...RAT/Smith
SYNOPSIS...STu

weather.gov/losangeles


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