959 
FXUS66 KLOX 121826
AFDLOX

Area Forecast Discussion
National Weather Service Los Angeles/Oxnard CA 
1126 AM PDT Thu Apr 12 2018

.SYNOPSIS...12/1057 AM.

Gusty winds are forecast into Friday, with possible precipitation
around the mountains this afternoon. A couple of highs and 
offshore flow should arrive, one on Friday and Saturday and again 
on Tuesday and Wednesday, that may bring above normal temperatures.
A couple of lows will arrive, one late Sunday, the other late next
week, to bring cool temperatures and possible precipitation, 
mainly north of Santa Barbara and in the mountains.

&&

.SHORT TERM (TDY-SAT)...12/928 AM.

Strong winds have arrived on schedule and with the expected 
intensity. Also getting a little snow near the Grapevine.
Expecting gusty winds to continue through this evening at least
before decreasing but still remaining breezy into Friday morning
as the flow shift to northeast. Across srn SB County there will 
be a second peak of winds later tonight as the northwest flow 
shift to northeast and starts to pound the western portion of the 
Santa Ynez range. SBA-BFL gradient ramps up to around -6mb at 5am
Friday so the high wind warning for that area will need to be 
extended at least until 9 am Friday. It definitely looks like a
scenario where the hills above Montecito will easily get wind 
gusts in excess of 60 mph. Unfortunately the weather station there
was burned in the Thomas fire so we won't get those reports but
confidence is high in a strong wind event there tonight.

***From previous discussion***

North winds switch offshore and weaken considerable by Friday
morning with a chance of advisory level winds continuing mainly
across the LA/VTA mountains. The offshore flow, rapidly rising H5
heights (568 dm to 578 dm) due to ridging aloft and sunny skies 
will support about 10 degrees of warming to many areas widespread 
highs in to 70s and a few low 80s for coastal valleys. The warming
trend continues into Saturday as H5 heights peak around 580 dm
with lingering weak offshore flow in the morning. Flow is expected
to shift onshore by the afternoon. This will result in several
degree of warming, especially away from the coast, with highs in
warmer valleys into the 80s. Some increases in mid to high level
clouds are possible by Saturday evening ahead of a storm system
approaching from the west.

.LONG TERM (SUN-WED)...12/401 AM.

Near normal confidence exists for the extended period despite
above average model agreement. 

Onshore flow is expected to increase in earnest Sunday with gusty
but likely below advisory level winds for far interior areas. High
clouds will likely also be on the increase with a chance of low
clouds returning to coastal areas, mainly north of Point
Conception Sunday evening. These ingredients combined with H5 
heights lowering from around 578 dm Saturday to around 572 dm 
Sunday will support significant cooling most everywhere with far 
interior areas seeing little change in high temperatures. 

A weakening cold front will bring a chance of mainly light rain to
SLO county Sunday evening and most areas north of Point Conception
Monday. This system may have a bit more westerly flow with it than
the current system moving overhead. As a result there is about a 
10 percent chance of the front holding together and bringing rain 
to areas south of Point Conception. Light snow is possible above 
4000 feet with any lingering shower activity behind the cold 
front. The cloud cover and below normal heights will likely result
in near to below normal temperatures for most areas Monday.

Moderate northerly to offshore flow with clearing skies and weak
ridging aloft will bring a brief, but likely modest warm up by 
Tuesday or Wednesday ahead of a potential third storm system, 
currently pegged to pass through the area next Thursday.

&&

.AVIATION...12/1825Z.

At 1712Z at KLAX, there was no marine inversion.

The northern slopes of the transverse mountains were mostly cloudy
with some mountain obscuration. Elsewhere, very strong north flow
was causing widespread strong gusty north to northwest winds 
across the area. Turbulence and low level wind shear are possible
almost everywhere today as the strong flow interacts with the
complex terrain. The conditions will continue throughout the day,
scale back in coverage tonight and improve by Friday.

KLAX...High confidence in the 18Z TAF. Possible LLWS all day and 
into this evening. Possible gusty north crosswinds this evening.

KBUR...High confidence in the 18z TAF. Possible LLWS all day and 
into this evening.

&&

.MARINE...12/943 AM.

Widespread gale force winds are expected across all waters today
in the wake of a dry cold front that has almost exited the
southern waters. The winds will continue through the night, except
decrease in coverage for the inner waters after midnight. Conditions
are expected to improve somewhat on Friday.

However, there is also a large northwest swell moving through the
coastal waters and in combination with the winds will create very
rough seas through tonight. The swell is expected to gradually
subside on Friday.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...High Surf Advisory in effect until 5 PM PDT Friday for zones
      34-35. (See LAXCFWLOX).
     Wind Advisory in effect until 10 PM PDT this evening for
      zones 34>36-40-87. (See LAXNPWLOX).
     High Wind Warning in effect until noon PDT Friday for zones
      39-52. (See LAXNPWLOX).
     High Surf Advisory in effect until 8 AM PDT Friday for zones
      39>41-87. (See LAXCFWLOX).
     Wind Advisory in effect until noon PDT Friday for zones
      41-44-45-88-547. (See LAXNPWLOX).
     Wind Advisory in effect until 6 PM PDT this evening for zone
      46. (See LAXNPWLOX).
     High Wind Warning in effect from 6 PM this evening to 1 AM
      PDT Friday for zone 46. (See LAXNPWLOX).
     High Wind Warning in effect until 1 AM PDT Friday for zones
      53-54-59. (See LAXNPWLOX).
PZ...Gale Warning in effect until 11 PM PDT this evening for zones
      645-650-655. (See LAXMWWLOX).
     Gale Warning in effect until 5 AM PDT Friday for zones
      670-673-676. (See LAXMWWLOX).

&&

.HAZARD POTENTIAL OUTLOOK (SAT-WED).

Gusty northwest winds will be possible Monday into Monday night.

&&

$$

PUBLIC...MW/Munroe
AVIATION...Sweet
MARINE...Sweet
SYNOPSIS...STu

weather.gov/losangeles