Gale Warning 18, NWS Los Angeles, CA

Area Forecast Discussion...UPDATED
National Weather Service Los Angeles/Oxnard CA
453 PM PDT Sun Jul 22 2018

updated aviation discussion

.SYNOPSIS...22/322 PM.

A high should build in through Thursday for fair skies with around
record maximum temperatures, and above normal nighttime temperatures.
The onshore flow will return to start the cooling trend on Friday.
Temperatures will stay above normal Friday and into the weekend
with the marine layer to bring in overnight clouds.

&&

.SHORT TERM (TDY-WED)...22/1237 PM.

Forecast remains largely in tact through next weekend. The heat
wave has begun but will really kick into gear Monday and Tuesday
with plenty of triple digit highs. Still not expecting this event
to come close to the numbers with the heat wave earlier in the
month but still close to or locally exceeding record levels. Main
action today was to convert the Excessive Heat Watch for northern
areas to a heat advisory. The primary reason for not going with a
warning up there is mainly due to the overnight lows recovering
into the 50s and lower 60s as opposed to the 70s in many areas in
the south. Also still considering a wind advisory for southern SB
County tonight. There's really not much question about advisory
level winds the Mon/Tue nights but tonight is more marginal in
terms of speeds and likely in low impact/low population areas.
Will take a look at the 1pm trends and decide from there. Either
way, the more impactful Sundowners will be Mon/Tue nights which
will be hotter, drier, stronger, and more widespread than tonight.

The rest of the forecast pretty much unchanged. Decreased stratus
coverage tonight south of Pt Conception given the minimal coverage
this morning and stronger northerly flow tonight. Still could be
some dense fog north of Pt Conception. Also bumped up highs a
degree or two based on most of the guidance trending in this
direction and the increase in forecast northerly gradients.

.LONG TERM (THU-SUN)...22/1244 PM.

Gradients will start trending onshore Thursday which will begin a
slow cooling trend going into next weekend. Temps will still be
well above normal through at least Friday but 5-10 degrees cooler
than earlier in the week. At this point not expecting heat
advisories/warnings after Thursday but could be a close call for
and advisory in some areas Friday. Monsoon moisture start to
increase across the area late Saturday into Sunday with the first
possibility for convection being on Sunday afternoon. May also
start to see some marine layer clouds returning to coastal areas
south of Pt Conception by next weekend.

&&

.AVIATION...22/2351Z.

At 2307Z at KLAX, the marine inversion was around 800 ft deep. The
top of the inversion was around 1800 feet with a temperature near
27 degrees Celsius.

Moderate confidence overall in the 00Z TAFs at KSBP and KSMX due to
the timing and extent of low clouds tonight into Mon morning. Low
clouds with LIFR/IFR cigs are expected to move into these airfields
generally from 04Z at KSMX to 08Z at KSBP. The low clouds are
forecast to dissipate about mid Mon morning with VFR conditions the
rest of the day. The timing of the onset and dissipation of the low
clouds may be off +/- one to two hours.

Elsewhere, generally hi confidence in the 00Z TAFs with mostly VFR
conditions expected thru Mon afternoon, except a few low clouds with
MVFR vsbys due to fog will be possible at KOXR, KSMO, KLAX and KLGB
late tonight and early Mon morning. There is also a 30% chance low
clouds with IFR/MVFR cigs could affect KLAX and KLGB at times late
tonight thru mid Mon morning.

KLAX...Generally hi confidence in the 00Z TAF. There should be
mostly VFR conditions thru Mon evening, except a few low clouds with
MVFR vsbys due to fog will be possible from about 11Z-17Z Mon
morning. There is also a 30% chance low clouds with IFR/MVFR cigs
could affect the airfield at times late tonight thru mid Mon morning.

KBUR...Hi confidence in the 00Z TAF with VFR conditions expected
thru Mon afternoon.

&&

.MARINE...22/209 PM.

For the outer waters...The 12Z models have increased the winds in
the coastal waters for early this coming week, and a Gale Watch
has been issued for zones 673 and 676. There is a forty percent
chance of the winds in the northern outer waters reaching SCA
level on Monday.

For the inner waters north of Point Conception...SCA conditions
are not expected through Monday morning then become more likely
during the afternoon and evening hours of Monday through Thursday.

For the inner waters south of Point Conception...SCA level winds
will develop this afternoon through late tonight across the
Santa Barbara Channel, especially western portions. There is a
forty percent chance of SCA level winds developing each afternoon
and evening through Wednesday, again mostly in western sections.
The winds across western sections of zone 650 also look strong
enough for SCA level winds from late this afternoon through late
tonight, so issued an SCA for that region.

&&

.BEACHES...22/1120 AM.

A long-period southerly swell will be moving through the coastal
waters producing strong rip currents and high surf conditions at
Southern California beaches Monday through Wednesday.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...Heat Advisory in effect from 10 AM Tuesday to 8 PM PDT
      Thursday for zones 34>38-51. (See LAXNPWLOX).
     Excessive Heat Warning in effect from 10 AM Monday to 8 PM
      PDT Thursday for zones 39>41-44>46-52>54-59-88-547.
     (See LAXNPWLOX).
     High Surf Advisory in effect from 8 AM Monday to 9 PM PDT
      Wednesday for zones 40-41-87. (See LAXCFWLOX).
     Fire Weather Watch in effect from Tuesday afternoon through
      Thursday morning for zones 239-252. (See LAXRFWLOX).
PZ...Small Craft Advisory in effect until 3 AM PDT Monday for
      zones 650-655. (See LAXMWWLOX).
     Small Craft Advisory in effect until 3 PM PDT Monday for
      zones 673-676. (See LAXMWWLOX).
     Gale Watch in effect from Monday afternoon through late
      Monday night for zones 673-676. (See LAXMWWLOX).

&&

.HAZARD POTENTIAL OUTLOOK (WED-SUN).

An extended heat wave is expected through at least Wednesday of
next week, especially for inland areas. Widespread elevated fire
weather conditions are expected to develop during this time.
Elevated to high surf is likely through Wednesday, focused across
south facing beaches.

&&

PUBLIC...MW
AVIATION...Sirard
MARINE...Sweet
BEACHES...Sweet
SYNOPSIS...STu

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