Hard Freeze Warning 2, NWS Los Angeles, CA

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
314 AM PST Sat Dec 17 2016

.SYNOPSIS...
Scattered snow showers across the north slopes, near the I-5
cooridor, will diminish this morning. Surface high pressure building
into the Northern Rockies late this weekend will support a weak to
moderate cool Santa Ana Wind Sunday into Monday. Gradual warming
with fair skies is expected through the middle of next week.

&&

.SHORT TERM...(TDY-MON)

The only weather at the moment is confined to the north slopes of
the mtns where strong north winds are pushing the moisture up
creating clouds and scattered snow showers. These wintery
conditions will last until late morning when the winds will drop
off. There is a winter weather advisory in effect for the north
slopes due to the combination of winds...snow...blowing snow and
very low wind chills. Otherwise today will be sunny and cool as
the low winter sun struggles to warm the cold airmass ushered in
by ydys cold front.

It will be an odd mix of wind and cold tonight. a large dome of
high pressure will set up over NE NV and set up moderate ne flow
over CA. Santa Ana winds just below advisory levels will develop
in the usual wind prone areas. But away from the winds the cold
air mass...dry air and clear skies will all combine to bring
freezing temps to a large portion of the area. Hard freeze
warnings are in now in effect for the Ojai vly...the Cuyama vly
and the SLO interior vly. While the less dangerous freeze warning
is in effect for the Central Coast...the Santa Ynez Vly and the
Ventura coastal vlys. In addition frost advisories for near
freezing temperatures are likely for almost all the rest of the
coasts and vlys save for the heat island of L.A. (which will still
see lows in the upper 30s) The Antelope Vly will be the coldest
area with lows dipping down into the teens. These very dangerous
low temperatures will be capable of bursting pipes.

Sunday will struggle to shrug off the very cold start to the day
although the offshore flow will help. Max temps will be a degree
or two warmer than today but still well below normal.

Look for another round of freezing temps on Monday morning as not
much will change min temps will likely be a degree or two warmer.
It will be windier. A ridge will nose into bay area overnight. The
location of the ridge will switch the upper level winds to the
northeast which will reinforce the winds at the sfc. The great
basin SFC high will also strengthen resulting in an impressive -8
mb offshore push from KDAG. If this all comes true there will be
strong advisory level gusts in the morning.

Aside the from the winds Monday will be sunny with low humidities.
The offshore winds will continue into the afternoon. Max temps
will rise to near normals across the area.

.LONG TERM...(TUE-FRI)

Offshore flow continues Tuesday, though weaker. Warmer temps
expected as ridging nudges in from the west and pushes out any
lingering cold air from the previous storm system. So by Tuesday
we should be back up to normal and maybe even a degree or two
above normal.

The rest of the week looks pretty quiet. The ridge will maintain
mild temps and clear skies through Thursday. Models struggling
beyond that time with poor agreement but so far nothing really
suggesting any additional precip chances through Christmas.

&&

.AVIATION...17/1100Z

At 1030Z, there was no marine layer or inversion at KLAX.

Good confidence in CAVU TAFs. Gusty north winds will likely
fluctuate from strong to weak through 15Z for L.A. county non
desert TAFs.

KLAX...Good confidence in CAVU TAF. There is a 20 percent chc of
of a 15-20 kt x-wind through 16Z.

KBUR...Good confidence in CAVU TAF.  Lgt turbc sfc-120 through
17Z.

&&

.MARINE...17/245 AM.

Gale winds have diminished across the coastal waters this morning.
Although winds remained quite gusty. A Small Craft Advisory will
continue for the outer waters through this evening. But there is a
50% chance that gusts might remain below SCA thresholds from mid
morning through mid afternoon hours. Otherwise winds should remain
under SCA levels Saturday through Wednesday of next week. There
is a 30-40% chance that a Small Craft Advisory might be needed
due to Santa Ana winds over the inner waters Monday. Weak offshore
winds will prevail Sunday through at least Wed morning.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...Frost Advisory in effect until 8 AM PST this morning for
      zones 34-35-44>46-547. (See LAXNPWLOX).
     Freeze Warning in effect from 2 AM to 8 AM PST Sunday for
      zones 34>36-45. (See LAXNPWLOX).
     Freeze Warning in effect until 8 AM PST this morning for zone
      36. (See LAXNPWLOX).
     Hard Freeze Warning in effect from 2 AM to 8 AM PST Sunday
      for zones 37-38-44. (See LAXNPWLOX).
     Winter Weather Advisory in effect until 10 AM PST this
      morning for zones 38-52>54. (See LAXWSWLOX).
     Wind Advisory in effect until 6 AM PST early this morning for
      zones 46-88. (See LAXNPWLOX).
PZ...Small Craft Advisory in effect until 9 AM PST this morning
      for zones 650-655. (See LAXMWWLOX).
     Small Craft Advisory in effect until 9 PM PST this evening
      for zones 670-673-676. (See LAXMWWLOX).

&&

.HAZARD POTENTIAL OUTLOOK...(MON-FRI)
Gusty advisory level Santa Ana winds possible Monday through
Tuesday.

&&

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

weather.gov/losangeles