874 
FXUS66 KLOX 171625
AFDLOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA 
925 AM PDT Wed May 17 2017

.SYNOPSIS...
Windy conditions and seasonal temperatures will continue through 
Friday associated with a low pressure center centered in the 
interior mountain west. Expect warming temperatures this weekend
as a ridge builds in its wake.

&&

.SHORT TERM...(TDY-FRI)

Another day with a deep but chaotic marine lyr coverage. Clouds
pretty solid in LA County and interior SLO but patchy elsewhere
due to northwest flow and a weakening inversion north of LA 
County. We're expecting to see decent clearing today except some
clouds lingering over LA County and interior SLO. Not much change
in high temps today from yesterday overall. Wind advisories
limping along this morning but should get a boost this afternoon
behind the trough passage. 

***From previous discussion***

For tonight into Thursday, low clouds should not be as widespread,
and likely affecting the Central Coast in a few locations, and
pretty much over the LA County Coast and possibly the SGV.
Otherwise most areas should start to warm up as high pressure
aloft continues to build in. There will be a quick burst of
relatively weak offshore winds Thursday morning, with the
seabreeze quickly moving in by noon. Expect high temps to be
around normal for this time of year in most areas. High temps will
tick upward 3-8 degrees across the board. Best warming inland.
Highs across the valleys will be in the mid to upper 70s with a
few lower 80s. A bit cooler along the coast. Not expecting much in
the way of low clouds Thursday night into Friday. There will be a
significant warm up on Friday as the upper ridge axis starts to 
move in across the western portion of California. The combination 
of increasing heights and thickness lvls, with a very late sub 
advisory Santa Ana event Friday morning, temps will rise 
significantly...especially across coast and coastal valley areas 
where temps are expected to rise another 5-8 degrees. Highs will 
finally be higher than normal. Highs will reach the mid 80s to 
lower 90s across warmest valleys, while inland coastal areas will 
reach the lower 80s. Should be the start of an awesome weekend.

.LONG TERM...(SAT-TUE)

The upper ridge will continue to build over the state through 
the weekend while an unseasonable weak offshore flow continues
through Saturday. Temps are expected to soar upward several 
degrees, peaking this weekend in most areas with highs in the 
lower to mid 90s in the valleys and 80s to the upper 80s for the 
interior coastal areas. Sunday should be a tad cooler along the
coast as the Seabreeze kicks in early. However inland temps should
be highest on Sunday. Winds should remain at sub-advisory levels
Fri/Sat mornings. More significant cooling is expected  for at 
least coast/valleys Monday with additional onshore flow and 
possible return of low clouds near the coast. And these trends 
continuing into Tuesday as a very weak upper low develops near the
area.

&&

.AVIATION...17/12Z...

At 1130Z, there was no marine inversion at KLAX, but there was a 
deep moist layer up to around 6000 feet.

Across SLO and SBA Counties, low clouds were widespread, with
generally IFR to low MVFR conds. The exception was across the
south coast of SBA County where it was clear. Cigs should lift 
into the MVFR category in these areas by mid morning, then clouds
should clear in most areas by late morning or just after noon. 
Gusty NW winds will affect much of SBA and SLO Counties in the 
afternoon and evening. 

Across coastal and western valley sections of VTU County, skies
were clear, which across L.A. County and far eastern Ventura 
County, there were widespread cigs, with mostly MVFR conds, except
IFR to LIFR conds in the mountains. Expect cigs to rise into the 
VFR category in most places by mid morning. Skies should clear by
early afternoon, except they could linger longer in the valleys, 
especially in the foothills. Gusty northwest to north winds will 
affect the I-5 corridor and the Antelope Valley through the 
period.

KLAX...Moderate confidence in the 12Z TAF. Cigs should fill back
into the airport by 13z. There is a 20-30% chance that cigs will 
linger through 23z, but they should rise into the VFR category 
after 17z.

KBUR...Moderate confidence in the 12Z TAF. There is a 20-30% 
chance that cigs will scatter out as early as 20z.

&&

.MARINE...17/900 AM...

For the Outer Waters, moderate to high confidence in the forecast
with SCA conditions continuing into early afternoon. Winds should
increase to gale force by mid afternoon. There is a 20-30% chance
that winds will remain below gale thresholds in the northern outer
water zone. Winds will diminish to SCA levels late tonight, then 
below SCA levels by late Thu night/early Friday thru the weekend.

For the northern Inner Waters, high confidence in current 
forecast with SCA conds from around noon or so thru this evening.
SCA conds are expected again Thu afternoon and evening.

Moderate to high confidence in the forecast for the SBA Channel. 
There is a 20% chance that SCA conds will not be met this afternoon
thru late tonight, or may be confined to far western sections.

Moderate confidence in the forecast for the southern inner waters.
A SCA has been issued for this zone from mid afternoon through
this evening.

&&

.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 5 AM PDT Thursday for zones
      39-52. (See LAXNPWLOX).
     Wind Advisory in effect until midnight PDT tonight for zones
      53-54-59-88. (See LAXNPWLOX).
PZ...Small Craft Advisory in effect until 9 PM PDT this evening
      for zone 645. (See LAXMWWLOX).
     Small Craft Advisory in effect until 3 AM PDT Thursday for
      zone 650. (See LAXMWWLOX).
     Small Craft Advisory in effect from 2 PM this afternoon to 9
      PM PDT this evening for zone 655. (See LAXMWWLOX).
     Small Craft Advisory in effect until 3 PM PDT this afternoon
      for zones 670-673-676. (See LAXMWWLOX).
     Gale Warning in effect from 3 PM this afternoon to 3 AM PDT
      Thursday for zones 670-673-676. (See LAXMWWLOX).

&&

.HAZARD POTENTIAL OUTLOOK...(FRI-TUE)
Temperatures will warm to well above normal levels by the 
weekend.

&&

$$

PUBLIC...MW/Kaplan
AVIATION...DB
MARINE...Sweet
SYNOPSIS...Fisher

weather.gov/losangeles