National Weather Service Raw Text Product

600 
FXUS66 KLOX 150142
AFDLOX

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA 
642 PM PDT Sat Oct 14 2017

.SYNOPSIS...

Offshore flow and high pressure will bring warm temperatures,  
gusty winds, and fire danger to portions of the area through the 
weekend. A warm air mass will linger into Wednesday, then a low 
pressure system could bring increasing clouds and cooler 
conditions with a possibility of rain later in the week.

&&

.SHORT TERM...(TDY-TUE)

A disappointing start to the Santa Ana winds today as the lack of
upper support has really delayed the onset, especially at lower 
elevations. Winds are finally picking up in the mountains and 
foothills with gusts into the 50s in a couple locations. And with
stronger gradients expected later tonight and Sunday morning and 
no marine inversion to worry about winds should have no trouble 
surfacing in the usual favored areas of LA/Ventura counties,
including the Oxnard/Camarillo plain and parts of the Malibu
coast. Still expecting winds to mainly stay below warning levels
due to a lack of upper support despite forecast gradients peaking
between 6 and 8 mb early Sunday.

Temperatures warmed up nicely today and more or less on target
except for the Ventura coast where as of 130pm winds were still
out of the west and temps only in the 70s. Another big bump in
temps Sunday with the stronger offshore push with most coastal
areas at least in the 80s with some lower 90s beyond a few miles
from the ocean. Valleys mostly in the 90s.

Offshore gradients weaken quite a bit Monday and Tuesday but still
remain offshore with a very warm air mass in place and the high
pressure ridge aloft hanging tough across So Cal. So temps will
remain well above normal with just some minimal cooling near the
coast. Warmer valleys will threaten triple digits but most areas
in the 90s.

.LONG TERM...(WED-SAT)

Weak offshore flow now expected to remain in place through
Wednesday and still pretty decent ridging aloft so again only
minimal cooling Wednesday with highs still 3-6 degrees above 
normal. 

After Wednesday forecast confidence drops quite a bit as models 
have been really bouncing around with the strength and timing of 
the next trough hitting the west coast as well as how much 
moisture it pulls in from the southwest. It looks like we should 
see at least one more dry day Thursday but cooler as gradients 
trend strongly onshore. And likely some marine lyr clouds
increasing as well. Both the GFS and ECMWF 12z solutions show the
trough axis moving onshore over Nrn CA around 18z Friday and
passing through the rest of the state Friday afternoon and
evening which is a good 12 hours delayed from earlier runs. 
Today's solutions are also noticeably less moist and don't drop 
quite as far south as previous runs showed and resulting precip 
forecasts are lower as well. In fact they are basically dry for 
most of LA/Ventura counties. But these solutions have varied 
considerably run to run and and it still looks like some chance of
rain late next week, though just not confident on timing and 
strength.

&&

.AVIATION...15/0137Z.

At 00Z, the marine layer depth was around 600 feet deep at KLAX. 
The top of the inversion was around 1200 feet with a temperature 
near 27 degrees Celsius.

Moderate-to-high confidence in VFR conditions throughout the
period. Moderate-to-strong wind shear and turbulence is possible
at all terminals through 16Z. 

KLAX...VFR conditions are expected throughout the period, except
for a 30 percent chance of MVFR conditions between 12Z and 16Z.

KBUR...VFR conditions are expected throughout the period. There is
a 30 percent chance of moderate wind shear and turbulence between
02Z and 12Z.

&&

.MARINE...14/200 PM.

Moderate short period hazardous sea conditions across the outer
waters will continue to diminish through the day today.

Gusty northeast winds across the nearshore waters will develop 
this afternoon and reach Small Craft Advisory (SCA) levels south 
of Point Conception this evening... primarily from Ventura to 
Santa Monica. The winds will diminish Sunday afternoon.

There is a twenty five percent chance that gusty northeast winds 
to 25 kt and short period northeast swell of 2 to 4 feet will 
affect Avalon Harbor this evening through Sunday morning.

&&

.FIRE WEATHER...14/205 PM...

Overall, everything still on track with regard to Red Flag
conditions across Ventura and Los Angeles counties. Offshore
winds are expected to increase this evening and overnight as
the surface pressure gradient increases. So, wind gusts between
35 and 55 MPH will be likely across Ventura and Los Angeles
county tonight and Sunday morning. The winds will diminish
gradually Sunday afternoon. As for relative humidity, very 
dry air will remain in place over the area through Sunday. So,
widespread and long-duration critical fire weather conditions
are expected and the Red Flag Warning will remain in effect
until 600 PM Sunday for Ventura and Los Angeles counties (except
for the Antelope Valley).

For Santa Barbara and San Luis Obispo counties, the offshore 
winds will be much weaker and more localized through Sunday.
However, the air mass will still be as warm and dry. So, elevated
fire weather conditions can be expected across these areas 
through Sunday evening.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...Wind Advisory in effect until 2 PM PDT Sunday for zones
      40-41-44>46-53-54-88-547. (See LAXNPWLOX).
     Red Flag Warning in effect until 6 PM PDT Sunday for zones
      240-241-244>246-253-254-288-547-548. (See LAXRFWLOX).
PZ...Small Craft Advisory in effect until 2 PM PDT Sunday for
      zones 650-655. (See LAXMWWLOX).

&&

.HAZARD POTENTIAL OUTLOOK...(TUE-SAT)
No significant hazards expected.

&&

$$

PUBLIC...MW
AVIATION...Hall
MARINE...Kj
FIRE WEATHER...Thompson
SYNOPSIS...jld/Hall

weather.gov/losangeles