Small Craft Advisory 50, NWS Los Angeles, CA

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
228 AM PDT Sun Apr 9 2017

.SYNOPSIS...
Offshore winds are forecast into Monday for clearing skies and a
warming trend. On Tuesday a low will approach for a cooling trend
with more clouds. Another possibility of precipitation from Lompoc
and northward by midweek...with the possibility to spread south
on Thursday. The low will exit the region on Friday and warm the
inland temperatures.

&&

.SHORT TERM...(TDY-TUE)

Mostly clear skies across the region early this morning, except
for patchy low clouds lingering across the interior mountains and
Cuyama Valley. The main weather concern overnight was the gusty
north winds that impacted the typical north facing passes and
canyons of Santa Barbara and Los Angeles counties. Wind advisories
in effect until 3 am, with a few of the zones possibly needing
to be extended for a few more hours. The strongest winds have
been focused across the Interstate 5 corridor of the LA county
mountains, where Whitaker Peak reported a peak gust of 67 mph and
Sandberg at 59 mph. The gusty north winds have spread all the way
into the LA county coast, with gusts locally exceeding 30 mph
across the Hollywood Hills and west side. The gusty north winds
being generated by favorable northerly upper level wind support
and offshore north-south pressure gradients (LAX-Bakersfield
peaking at -5.3 mb). During the next few hours, the upper level
winds will begin to shift to the northeast, with most areas
expected to see a slight reduction in wind speeds through the
morning hours.

The weak offshore flow will bring a warming trend today, with
temperatures climbing well into the 70s across coastal/valley
areas. Another round of gusty northwest winds expected this
afternoon, shifting to the north by tonight. Winds will once again
approach advisory levels across the favored passes and canyons
of southern SBA county as well as the I5 corridor in the LA
County mountains. Weak offshore flow and rising boundary layer
temperatures will bring continued warming on Monday, with warmest
valley areas expected to reach the lower 80s.

By Tuesday, the upper level flow pattern will become more zonal
allowing for increasing higher level clouds. In addition, there
will be the potential for a return of low clouds and fog across
coastal portions of LA/Ventura counties as pressure gradients
begin to trend onshore.

.LONG TERM...(WED-SAT)

The EC and GFS continue to be in fairly good agreement with large
scale features and the timing of precipitation Wed and Thu. The
latest EC and GFS model runs now are in better agreement that
there will be no additional precip for Fri/Sat. However, the GFS
keeps broad upper level troffiness along and off the w coast Fri
and Sat, while the EC gradually builds a flat upper ridge into srn
CA.

For Wednesday...A cold front associated with the upper trof
will approach the Central Coast with a slight chance of showers.
The front is expected to push into SLO/SBA counties by Wednesday
night with rain chances increasing for areas N of Point
Conception. For now, will go with slight chance POPS for
everywhere S of Point Conception as the front washes out reaching
Ventura/L.A. Counties sometime late Thursday morning. Both models
are not bullish with rainfall amounts with this system, but some
areas such as the SLO County coastal foothills could recieve
moderate amounts of rain. Dry weather with decreasing clouds can
then be expected Thu night, with mostly clear skies for Fri thru
Sat.

A minor cooling trend is expected for Wednesday with more
significant cooling on Thursday as the frontal boundary moves
through the region. Some weak ridging and weak offshore flow
behind the exiting front should lead to 3-6 degrees of warming for
Friday in most areas with similar temps expected on Saturday. If
the GFS pans out, some cooling could occur for areas N of Point
Conception as another upper trough is expected to move towards the
west coast. Highs in the warmest vlys and inland coastal areas
should be in the mid 70s to upper 70s for Wed, cool to the upper
60s to low 70s Thu, then warm to the 70s Fri and Sat.

&&

.AVIATION...09/0520Z.

At 0520z at KLAX...there was no marine layer.

VFR conditions will be most common through Sunday. A 20 percent
chance of MVFR CIGS at KPRB and KLGB late tonight through early
Sunday morning. Gusty north winds tonight...with a 60 percent
chance of 20+KT affecting KVNY KSMO KLAX at times through 10Z.
When/if winds do not surface, LLWS issues will prevail.

KLAX...North wind potential highest concern tonight...as 25 KT
north winds will exist above 1,000 feet. North winds likely
gusting 20+ KT at surface through 10Z. When/if winds do not
surface, LLWS issues will prevail tonight. High confidence
in VFR conditions through Sunday.

KBUR...High confidence in VFR conditions through Sunday.
Moderate confidence on north winds surfacing at times tonight.

&&

.MARINE...09/200 AM.
Current Gale Warnings will be allowed to expire at 3 am as winds
begin to diminish. However, gale force winds are expected to
redevelop across the outer waters (zones 673, 676) by this
evening, with small craft conditions across remaining coastal
waters. The large swell will continue to slowly decay today.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...Wind Advisory in effect until 3 AM PDT early this morning for
      zones 39-52. (See LAXNPWLOX).
PZ...Small Craft Advisory in effect until 3 AM PDT early this
      morning for zones 645-670. (See LAXMWWLOX).
     Gale Warning in effect until 3 AM PDT early this morning for
      zones 650-655-673-676. (See LAXMWWLOX).

&&

.HAZARD POTENTIAL OUTLOOK...(TUE-SAT)
A frontal system bring a chance of rain to the area Wednesday
afternoon thru Thursday. Most areas should have light amounts of
rain, but there is the potential for moderate rainfall across
northwestern San Luis Obispo County.

&&

PUBLIC...Gomberg/Kaplan
AVIATION...Gomberg
MARINE...Gomberg
SYNOPSIS...STu

weather.gov/losangeles

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
918 PM PDT SAT APR 8 2017

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

0857 PM     NON-TSTM WND GST 6 NE PYRAMID LAKE       34.74N 118.72W
04/08/2017  M56 MPH          LOS ANGELES        CA   ASOS

            ASOS STATION SDB, SANDBERG.

&&

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
154 AM PDT SUN APR 9 2017

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

0911 PM     NON-TSTM WND GST 6 NE PYRAMID LAKE       34.74N 118.72W
04/08/2017  M59 MPH          LOS ANGELES        CA   ASOS

            ASOS STATION SDB, SANDBERG.

&&

CK