Area Forecast Discussion
Issued by NWS Los Angeles, CA

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000
FXUS66 KLOX 280349
AFDLOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
849 PM PDT Thu Apr 27 2017

.SYNOPSIS...
A ridge of high pressure over the Eastern Pacific will move
onshore tonight through Saturday. Strong north winds will continue
through Friday before turning offshore on Saturday. Above normal
temperatures are expected to peak across the area over the
weekend, but will continue into next week.

&&

.SHORT TERM...(TONIGHT-SUN)

Fair skies with some hi clouds at times were noted across the
forecast area early this evening, with little change expected
overnight.

Gusty nw to n winds prevailed across much of the region early this
evening, with the strongest winds in the L.A. County mtns. The Camp
9 RAWS station recently reported a gust of 62 mph. Many parts of the
area from the Central Coast, s SBA County coast and mtns, and much
of VTU/L.A. Counties have had gusts of 30 to 45 mph early this
evening. The winds on the Central Coast should diminish some
overnight, while elsewhere there will be support (e.g., 850 mb winds
up to 50 kt and 950 mb winds up to 35 kt) for stronger winds
overnight into Friday morning. Gusts up to 65 mph will be possible
in the L.A./VTU mtns, with gusts of 40 to 50 mph or more at times
for the SBA County s coast and mtns, VTU County vlys, L.A. County
vlys, Antelope Vly, and portions of the L.A. County coast especially
from Malibu to the Hollywood Hills. The strongest winds will
generally be below and thru the passes and canyons. A High Wind
Warning will continue into Fri morning for the L.A./VTU County mtns,
with Wind Advisories elsewhere. Please see the latest Non-
Precipitation Weather Message (LAXNPWLOX) for further details.

Srn CA will be sandwiched between an upper high over the e Pac and
an upper trof over the Great Basin late tonight through Sat night,
with a strong nw to n flow aloft. The upper trof will move e Sat
night and Sun, with the upper ridge gradually expanding into CA.

Mostly clear skies will prevail across the forecast area Fri thru
Sun thanks to offshore flow over the region.

The gusty nw to n winds Fri morning should diminish some by Fri
afternoon. It looks like gradients will turn more ne Fri night and
become decently offshore by early Sat morning (NAM fcst -3.9 mb LAX-
DAG at 12Z Sat). In addition, the 00Z NAM was predicting 850 mb
winds up to 55 kt over the mtns, and 950 mb winds up to 40 kt over
the vlys and cst of VTU/L.A. Counties for late Fri night and early
Sat. There will be the possibility of damaging wind gusts in the
L.A./VTU mtns Fri night into Sat morning, with advisory level gusts
for most of the L.A./VTU vlys and some coastal areas. Another round
of High Wind Warnings and Wind Advisories will be possible for these
areas. Gradients weaken quite a bit Sat night into Sun morning, with
just weak offshore flow expected in the favored areas.

Temps are forecast to be several degrees above normal for many areas
Fri, then warm to 5 to 15 deg or more above normal Sat before
cooling slightly to 5 to 12 deg above normal overall for Sun. Highs
in the warmest vlys and inland coastal areas should reach the 80s on
Fri, mid 80s to lower 90s Sat, and 80s to around 90 on Sun.

***FROM PREVIOUS DISCUSSION***

.LONG TERM...(MON-THU)

Fairly quiet week next week as the ridge eventually moves squarely
over the west coast and dominates the pattern. Pretty standard
onshore flow each day so while above normal temps will continue
highs should mostly top out in the 70s for the coast and 80s for
the valleys. 90s likely reserved for the extreme inland areas like
the Antelope Valley and interior SLO County. This pattern is
definitely favorable for a marine lyr return at some point next
week, but exactly when is hard to say. When it does it will be
confined to the coast and likely include areas of dense fog as the
inversion will be very strong but also very shallow.

&&

.AVIATION...28/0010Z

At 2317Z, The inversion at KLAX was 400 ft deep. The top of the
inversion was at 1000 ft with a temperature of 24 deg C.

Hi confidence in the 00Z TAFs with VFR conditions expected at all
the airfields thru Fri afternoon. Gusty nw to n winds will affect
many of the airfields for much of the TAF period. There will be an
extended period of low level wind shear at KSBA from 02Z-14Z due to
the gusty n canyon winds in the vicinity. Winds gusting to near 40
kt at KPMD and KWJF thru early this evening will bring a 10-20
percent chance of MVFR/IFR vsbys at times in blowing dust. At
KLAX...n winds gusting to 25 kt is expected later tonight into early
Fri morning.

KLAX...Hi confidence in the 00Z TAF with VFR conditions expected
thru Fri evening. N winds gusting to 25 kt is expected from 08Z-14Z,
with a 20 percent chance of gusts to 30 to 35 kt as well.

KBUR...Hi confidence in the 00Z TAF with VFR conditions expected
thru Fri afternoon. Gusty n winds will prevail at the airfield at
times, peaking tonight with gusts up to 25 kt, and there is a 20-30
percent chance of gusts 30 to 35 kt at times.

&&

.MARINE...27/830 PM.

For the Outer Waters, high confidence in current forecast. Gale
force winds will continue through Friday night then subside to
Small Craft Advisory (SCA) levels Saturday through Monday.

For the Inner Waters, moderate to high confidence in current
forecast. For the waters north of Point Sal, strong SCA level
winds will continue through Friday night before subsiding on
Saturday. For Sunday and Monday, there is a 50% chance of winds
increasing to SCA levels again. For the waters south of Point
Conception, SCA level west to northwest winds will continue
through Friday night. From Saturday through Monday, winds are
generally expected to remain below SCA levels. However, there is a
50% chance of SCA level northeast winds Saturday from Ventura
south to Santa Monica.

Due to strong winds throughout the waters, seas will be large and
very choppy in all areas this week, creating hazardous boating
conditions.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...Wind Advisory in effect until 9 PM PDT this evening for zones
      34-35. (See LAXNPWLOX).
     Wind Advisory in effect until 9 AM PDT Friday for zones
      39-44>46-52-59-547. (See LAXNPWLOX).
     Beach Hazards Statement in effect through Friday evening for
      zones 40-41. (See LAXCFWLOX).
     High Wind Warning in effect until 9 AM PDT Friday for zones
      53-54. (See LAXNPWLOX).
     Wind Advisory in effect until 3 PM PDT Friday for zone 88.
     (See LAXNPWLOX).
PZ...Small Craft Advisory in effect until 3 AM PDT Saturday for
      zones 645-650-655. (See LAXMWWLOX).
     Gale Warning in effect until 3 AM PDT Saturday for zones
      670-673-676. (See LAXMWWLOX).

&&

.HAZARD POTENTIAL OUTLOOK...(SUN-THU)
No significant hazards expected.

&&

$$

PUBLIC...Sirard/MW
AVIATION...Sirard
MARINE...Smith
SYNOPSIS...Smith

weather.gov/losangeles



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