Small Craft Advisory 28, NWS Los Angeles, CA

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
1107 AM PST Mon Feb 20 2017

.SYNOPSIS...
Light rain showers will continue through Tuesday, with local
showers and gusty north winds on Wednesday, mainly to the north
and in the mountains. Thursday looks to be the coldest night.
Drier weather is expected late in the week. Another storm is
possible next weekend.

&&

.SHORT TERM...(TDY-WED)

A trough of low pressure off the Pacific Northwest coast will
maintain a deep layer of south to southwest flow over the region
through Tuesday. This flow will interact with a very shallow layer
of moisture to produce ample drizzle/light rain over much of the
coastal and valley areas into Tuesday. Due to the low elevation
nature of the moisture, radars will struggle to detect the rain,
but area rain gauges will tell the story better. There is also an
area of deeper moisture currently over north and central
California that will slowly progress down the coast into Tuesday,
which will enhance rainfall mainly over SLO and SBA Counties
tonight. Overall, additional rain amounts between 0.50 and 1.00
inches are expected for the west and south portions of SLO and SBA
counties, with much lighter amounts everywhere else. Updated
cloud and PoP forecast through Tuesday...and thinking PoPs will
need to be upped more for LA and Ventura Counties Tuesday morning.
Otherwise forecast is in good shape...and wind advisories will
remain in play as is. The LA mountains and Antelope Valley will
also flirt with a wind advisory today and tonight.

***From Previous Discussion***

A little trof or front embedded in the WSW flow will bring an
uptick of rain to the area (esp SLO and SBA counties) later
tonight. The rain will continue Tuesday morning but then will
taper off during the afternoon.

Although the WSW flow aloft will continue on Wednesday the
moisture will have wrung itself out and skies will start to
clear. The only chc of rain (or snow) will be across the north
slopes as low level north to south sets up. The low level north
flow will be strong enough to bring gusty winds through the N/S
passages.

Below normal temps will continue all three days. Max temps across
the coasts and vlys will remain mired in the lower to mid 60s.

.LONG TERM...(THU-SUN)

A little inside slider will move down the state line Wednesday
night. It will have little effect on the weather in terms of rain
but it will serve to reinforce the north flow and it looks like
most of the mtns and some areas with N.S oriented canyons will see
advisory level wind gusts. It will also bring more cool air to the
region and its possible that Thursday will be the coolest of the
next 7.

The most minimal of all ridges slides into the area Friday. It
will be dry and there will be a slight nudge up in the temps.
There should be a decent amount of sunshine although SLO county
may see some increase in the clouds during the afternoon.

Both the GFS and the EC bring some energy to the area over next
weekend. The EC is drier and less energetic that the GFS. Still
with the wet GFS have to keep pops going through the weekend with
the better chc occuring north of Point Conception. Despite being
wetter than the EC the GFS storm is no barn burner.

&&

.AVIATION...20/1800Z.

At 1708Z at KLAX... There was no marine inversion.

Low confidence in the 18z TAFs. A steady stream of moisture
continues to flow in from the eastern pacific causing MVFR to IFR
ceilings and little change is expected for the next 24 hours. The
greatest uncertainty is the constant changes in ceiling and
visibility. Most precipitation will occur north of Point
Conception, but occasional showers are also possible all the way
down to Los Angeles county.

KLAX...East winds of 10 knots continue at the airfield and there
is little chance of the winds shifting around to the west this
afternoon (20 Percent). However, the wind speed should drop below
7 knots between 23z and 03z. By tomorrow morning the wind will
again line up out of the east, however there is a 50 percent
chance that speeds will remain below 7 knots. The period will
likely be characterized by MVFR to IFR ceilings and visibility
through the period.

KBUR...The period will likely be characterized by MVFR to IFR
ceilings and visibility through the period.

&&

.MARINE...20/900 AM.

Southerly winds will increase today ahead of an approaching cold
front.  Small Craft Advisory (SCA) level winds across the
northern waters will likely become gale force midday through this
evening. SCA level winds may also affect the western portion of
the Santa Barbara Channel this afternoon and evening.

Winds will diminish to below advisory levels by Tuesday morning
but then increase again overnight Tuesday into Wednesday and will
likely reach SCA levels Wednesday and Thursday.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...High Surf Advisory in effect until 4 PM PST Tuesday for zones
      34-35. (See LAXCFWLOX).
     Wind Advisory in effect until 6 AM PST Tuesday for zones
      34-35-37-51-52. (See LAXNPWLOX).
PZ...Small Craft Advisory in effect until 4 PM PST this afternoon
      for zone 645. (See LAXMWWLOX).
     Gale Warning in effect from 4 PM this afternoon to 10 PM PST
      this evening for zone 645. (See LAXMWWLOX).
     Gale Warning in effect until 9 PM PST this evening for zone
      670. (See LAXMWWLOX).
     Small Craft Advisory in effect until 9 PM PST this evening
      for zone 673. (See LAXMWWLOX).

&&

.HAZARD POTENTIAL OUTLOOK...(WED-SUN)
Gusty north winds are expected Wednesday night into Thursday which
will create hazardous road conditions and possible downed trees.
More rain and wind is possible on Saturday.

&&

PUBLIC...Rorke/Kittell
AVIATION...sweet
MARINE...Sweet
SYNOPSIS...B

weather.gov/losangeles