National Weather Service Raw Text Product

324 
FXUS66 KLOX 091159
AFDLOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA 
459 AM PDT Tue May 9 2017

.SYNOPSIS...
Northeast flow around a low over Baja Mexico will bring a slight
chance of showers and thunderstorms to interior sections through 
Wednesday. In addition...low clouds and fog will affect the coast 
and some valley areas during the night to morning hours each day 
this week. Another low will bring below normal temperatures...and 
a chance of light rain or drizzle west of the mountains next 
weekend.

&&

.SHORT TERM...(TDY-THU)

The weekends upper low is now positioned to the SW of AZ. There 
is NE upper level flow over SRN CA from this low. Embedded clouds 
in this flow will bring partly cloudy skies to the area late this 
morning. Just enough moisture and instability will creep into the 
area this afternoon to warrant a slight chc of TSTMs for the 
VTA/LA mtns as well as the Antelope Vly.

The eddy that was supposed to be spinning right now never happened
and as a result there is much less stratus south of Point
Conception and the marine layer north of Point Conception is much
lower than fcst which has resulted in some dense fog there.

Without the eddy the low clouds are just now starting to form and
will likely continue to expand until a few hours past dawn. The
inversion is fairly strong as is the onshore push to the east so
any beaches that are cloudy in the morning will likely struggle to
clear in the afternoon. Max temps across the coasts and vlys will
be cooler than ydy but perhaps will be a little warmer than fcst
due to the less robust stratus coverage pattern.

A little vort max ripples over LA and far eastern VTA county
tonight and Wednesday morning. It is not that impressive but worth
a 20 percent chc of a shower. Otherwise there will be a very deep
marine layer and coasts and most of the vlys will be swaddled in
stratus. The marine layer should lift from 1500 or 2000 feet to
4000 feet or higher. This kind of deepening may well lead to some
drizzle esp near to the foothills. At the upper levels a ridge
will build into the area and further strengthen the inversion.
This will make clearing difficult for many beach areas. There will
be little change in temps for the coasts and vlys but there will
be warming across the inland areas.

The stratus pattern will continue on Thursday. The ridge will
continue to build so the low clouds may be squashed out of a few
of the vlys. Again some beaches may see no sunshine and there will
be little chg in max temps across the coasts but some warming
inland.

.LONG TERM...(FRI-MON)

Broad west coast troffing will establish itself for the extended
forecast. Normally this would be a slam dunk night through morning
low clouds and fog pattern will slightly below normal max temps.
But a SFC high develops to the north and sets up decent north flow
across the area. This will likely keep the San Fernando vly and
the SBA south coast clear and will allow max temps to be a little
warmer than typical for this sort of pattern.

&&

.AVIATION...09/12Z.

At 1130Z, the marine layer depth was around 1900 feet at KLAX. 
The top of inversion was around 3400 feet with a temperature near
19 degrees Celsius.

Clouds have become widespread in most coastal and valley areas
this morning. Conditions were generally MVFR across L.A. County
and IFR elsewhere. Expect cigs to cont to rise, with cigs becoming
MVFR is most areas by mid or late morning. It is likely that MVFR
cigs will linger through the day, especially in coastal sections
south of Pt. Conception. Where clouds do scatter out, cigs will
likely arrive again this evening, with generally MVFR conds
expected overnight.

KLAX...Moderate confidence in the 12Z TAF. There is a 20-30%
chance that cigs will scatter out between 19z and 01Z.

The wind forecast is trick. There is a 20-30% chance that there 
will be an easterly or southeasterly wind component equal to or 
greater than 10 kt from 14z through 20Z.

KBUR...Moderate confidence in the 12Z TAF. There is a 20-30%
chance that cigs will linger through the day.

&&

.MARINE...09/300 AM.

Good confidence that Small Craft Advisory winds and seas will
end across the outer waters by mid morning. Then, SCA conds are
not expected through Thu, although southeast winds may get close
to SCA levels from northwest of Catalina Island through western
portions of the SBA Channel and near shore areas north of Point
Conception late tonight through Wed morning. 

A strong high will move into the East Pacific late in the week...
with a good chance of SCA conds across much of the waters
Friday and Saturday, and a chance of Gale Force winds, especially
across the outer waters.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
PZ...Small Craft Advisory in effect until 9 AM PDT this morning
      for zones 670-673-676. (See LAXMWWLOX).

&&

.HAZARD POTENTIAL OUTLOOK...(THU-MON)
High surf and strong rip currents are possible for late week at
area beaches.

&&

$$

PUBLIC...Rorke
AVIATION...DB
MARINE...DB
SYNOPSIS...Smith

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