717 
FXUS66 KLOX 091727
AFDLOX

Area Forecast Discussion
National Weather Service Los Angeles/Oxnard CA 
927 AM PST Thu Nov 9 2017

.SYNOPSIS...
A weak cold front will dissipate as it reaches San Luis Obispo
County this morning. There could be a few showers in the northern
portion of the forecast area this morning. High temperatures will
remain a bit below or near normal through early next week as an 
upper trough lingers over the forecast area.

&&

.SHORT TERM...(TDY-SAT)

Weak frontal boundary along the Central Coast generating some
light rain there, mainly SLO County, but not really showing up on
radar. Showers expected to wind down through the day. Further 
south, marine layer stratus was predictably hit and miss and as 
the inversion was too weak to support any sort of solid stratus 
layer. But now we're seeing some stratocu developing that will 
keep skies at least partly cloudy through the day, possibly mostly
cloudy in some areas, especially the San Gab Valley. Forecast 
looks on track and not expecting any big changes this afternoon.

***From previous discussion***

There should be enough low level moisture across all of the coasts
and vlys tonight for enough stratus to form to call the skies
mostly cloudy. The inversion, however, may not be strong enough to
support widespread stratus formation. The westerly flow will
continue over the area Friday and there will be enough mid and
high level clouds to call the day partly cloudy.

Northerly sfc flow develops Friday night as high pressure builds
into the Central vly. There will be a 15 to 25 mph sundowner and
some gusty winds through the I-5 corridor as well. Weak offshore
flow even develops from the east and this will limit the stratus
formation and inland push to the LA and VTA coast and in fact this
may be a little pessimistic.

The sort of moist westerly flow will continue over the area
Saturday and skies will be just this side of partly cloudy.

Max temps will be 1 or 2 degrees below normal and will change
little from day day.

.LONG TERM...(SUN-WED)

A little ridge pushes up from the north on Sunday and this along
with weak offshore flow will make it the warmest day of the next 7
with max temps about 3 degrees above normal in most areas. There
may be some morning low clouds across the VTA and LA county
coasts.

The ridge flattens out on Monday and the flow turns more westerly.
The west flow will bring partly cloudy skies with both mid and
high level clouds moving over the area. Weaker offshore flow will
allow for a bit more morning stratus. The extra clouds and weaker
offshore flow will bring a couple of degrees of cooling to the
area.

A little wave moves through the flow over nrn CA and flattens the
flow out a little more. It does set up better north flow at the
sfc and this should be enough to keep the marine layer clouds
away. It looks like the westerly flow will dry out and skies
should be mostly sunny. Max temps will be very similar to Mondays.

The EC and GFS are not in the best of agreement for Wednesday but
its mostly semantics. It should be pleasant day with mostly sunny
skies and max temps a couple degrees cooler than Tuesday and thus
2 to 3 degrees blo seasonal normals.

&&

.AVIATION...08/1145Z

At 0930Z at KLAX, there was a weak marine layer with a depth of 
1300 feet. The top of the inversion was near 1700 feet with a 
temperature near 15 degrees Celsius.

low confidence in TAFs. Cigs were varying from LIFR to IFR across
LA County Valleys to IFR to MVFR in most other coast and valley
locations. Cigs should improve to MVFR for most areas after 17z
this morning. Cigs are expected to reach VFR sometime this
afternoon into tonight. The marine layer is quite weak so
difficult to pinpoint when cigs will jump up and how long cigs
will persist through much of today. Looks like a weak front will
bring a few sprinkles N of San Luis Obispo through this morning.

KLAX...Low confidence in 12Z TAF. Taf should go up from IFR to
MVFR or VFR by 18z. Cigs could remain in MVFR longer than what is
in the TAF. Low confidence with timing of cigs persisting or it
could dissipate earlier this afternoon. 

KBUR...Low to Moderate confidence in 12Z TAF. LIFR conds should
quickly become IFR then to MVFR by this afternoon. Low confidence
in timing of CIG categories and how long will stratus continue
into this morning/afternoon hours.

&&

.MARINE...09/300 AM.

High confidence in the current forecast. Winds and seas are expected
to remain below SCA thresholds across the waters through today. 
However, there is a 50% chance for local gusts to 25 knots across
the inner Santa Barbara Channel and near Anacapa Islands late 
this afternoon into the evening. Friday night through the 
weekend, winds will increase from the northwest with SCA 
conditions likely over much of the outer waters, mainly south of 
Point Sal. SCA west to northwest winds will be possible over 
portions of the inner waters...including the the western Santa 
Barbara Channel. Across the outer waters...seas will build to 7 to
9 feet tonight through Friday.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
PZ...NONE.

&&

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

&&

$$

PUBLIC...MW/Rorke
AVIATION...Kaplan
MARINE...Kaplan
SYNOPSIS...Kaplan/B

weather.gov/losangeles