January 19, 2018
Temp
 
53.5 °F
 
Dew Pt.
 
51.2 °F
 
Humidity
 
92%
 
Pressure
 
1012.5 hPa 
  rising slowly
Wind
 
0.0 mph 
    NW
Rain
 
0.03 in 
  0.00 in/hr
UV index
 
---  
 
Solar rad.
 
100 W/m²
 
Tonight

Tonight: A 30 percent chance of showers, mainly before 10pm.  Partly cloudy, with a low around 44. West northwest wind 5 to 10 mph.
Chance
Showers
Saturday

Saturday: Sunny, with a high near 60. West wind around 10 mph, with gusts as high as 15 mph.
Sunny
Lo 44 °F Hi 60 °F
000
FXUS66 KLOX 192207 AAA
AFDLOX

Area Forecast Discussion...UPDATED
National Weather Service Los Angeles/Oxnard CA
207 PM PST Fri Jan 19 2018

Corrected

.SYNOPSIS...
Low pressure will bring much cooler temperatures, gusty winds,
and a chance of light rain and mountain snow showers to the region.
Snow showers should linger tonight into Saturday morning on the
north slopes, with hazardous driving conditions on the Interstate
5 Corridor around the Grapevine. Otherwise fair, breezy and cool
weather can be expected Saturday and Sunday. Warmer conditions
will return next week, with a slight chance of showers mainly on
the Central Coast early next week.

&&

.SHORT TERM...(TDY-MON)

The core of a cold upper level trough is currently just off the
northern California coast, and will swing through southern
California tonight. A few light showers could form anywhere for
the rest of the day, but the flow will turn from southwest/west
to northwest/north by this evening, and shift the focus of
precipitation to the northern slopes and interior valleys. With
fairly strong winds pushing low level moisture up the slopes,
precipitation amounts should range between 0.25 and 0.50 inches,
but amounts will be highly dependent on the terrain and therefore
highly variable. Snow levels will be dropping through
tonight...bottoming out around 3,000 feet. This means that the
mountain roads, including the I-5 Tejon Pass/Grapevine should be
impacted by accumulating snow and gusty winds. Road closures are
possible. The Central Coast and eastern Los Angeles County could
also get a few showers in this flow pattern, and cannot discount a
stray shower drifting off the mountains into the coastal valleys
as well. Overnight temperatures will be cool, but moderated by the
clouds and wind.

The gusty northerly winds will continue Saturday and Saturday
night, but the moisture and associated precipitation chances will
be on the decrease. While the Santa Clarita and San Fernando
Valleys, as well as the Santa Monica Mountains, should be breezy
tonight with the northerly flow, the LAX-BFL gradient does not get
very strong and just cannot see those areas reaching advisory
strength. So did not expand the current Wind Advisory. Those areas
may still need to be added for Saturday afternoon and night, but
not confident enough to do that now. Temperatures will drop 5-10
degrees tomorrow (except for SLO and SBA Counties which already
saw their cooling today). Overnight temperatures Saturday night
into Sunday will be the coldest of the week as the winds weaken
late and the clouds go away. Some coastal valley areas will have
some frost issues and a few Frost Advisories may be needed.
Daytime Sunday should be a bit warmer with more sunshine as weak
ridging forms aloft.

An upper level trough will move through Washington state on
Wednesday, with a weak front moving down the coast. There is a
chance that this front clips SLO or northern SBA Counties Sunday
night into Monday before it dissapates. Otherwise, the passing
front will bring another round of gusty northerly winds Monday
afternoon and night that might require wind advisories in the
mountains and Sundowner country. Those winds, coupled with a quick
pop-up ridge behind the front will actually bring a few degrees of
noticeable warming. Coastal and valley areas might actually push
up to normal temperatures.

.LONG TERM...(TUE-FRI)

Warmer conditions are expected Tuesday under weak ridging aloft,
with locally breezy northerly winds. Another storm system will
impact the area late Wednesday through early Friday. While it is
still very early and the details will likely waver some, the
characteristics of this storm look very similar to today`s system.
Light rain is possible Wednesday night into Thursday followed by
lower elevation snow potentially impacting the mountain passes
Thursday night into Friday. The winds look just as gusty, if not
slightly stronger as well. Temperatures will fall as no surprise.

&&

.AVIATION...19/1655Z...

At 1630Z, the marine inversion at KLAX was based at 2300 feet. The
top of the inversion was 3600 feet with a temperature of 11
degrees Celsius.

Overall, low to moderate confidence in 18Z TAF package. Weak front
will move across the area today, bringing VFR to MVFR CIGs/VSBYs
to most sites. Through the afternoon, CIGs will likely bounce
between MVFR and VFR, leading to low confidence in timing of
flight category changes. For this evening and overnight, gusty
north winds will develop with LLWS/turbulence likely at KSBA as
well as through the local mountain passes. There will be some
northwesterly winds across the LAX basin as well.

KLAX...low confidence in 18Z TAF. Current MVFR CIGs could
dissipate up to 3 hours earlier than current 23Z forecast. There
is a 40% chance of northerly cross winds 20 kt or greater 06Z-
18Z with associated LLWS issues.

KBUR...low confidence in 18Z TAF. Current MVFR CIGs could
dissipate up to 4 hours earlier than current 02Z forecast. There
is a 30% chance of LLWS/turbulence after 06Z.

&&

.MARINE...19/100 PM...

For the Outer Waters, moderate to high confidence in current
forecast.

Across the southern two outer waters zones (PZZ673, PZZ676),
a Gale Warning is in effect thru Sat evening. There is a 20%
chance that winds will remain below gale force there.

Across the northern zone (PZZ670), SCA conds are expected thru
Sat night. There is a 20% chance that winds will reach gale force
across the northern zone (PZZ670) thru Sat.

For the inner waters north of Point Sal, moderate to high confidence
in the current forecast with SCA conds thru Sat night. There is a
20% chance of gale force winds this afternoon thru Sat evening.

Across the SBA Channel and the southern inner Waters, moderate to
high confidence in the forecast with gale force winds through Sat
evening. There is a 20% chance that winds will remain below gale
force through Sat.

Very large NW swell will affect all waters today and tonight,
then swell will slowly subside Sat and Sat night. Dangerous
breaking waves are possible near harbor entrances, including
Morro Beach Harbor and Ventura Harbor through Saturday

&&

.BEACHES...19/100 PM....

An extended period of large surf is expected to continue along
west to northwest facing beaches through Saturday evening as very
large westerly swells move through the coastal waters.

For west and northwest facing beaches along the Central Coast,
surf will average 15 to 20 feet with local sets to 25 feet today,
then surf will slowly subside tonight through Saturday evening. A
HIGH SURF WARNING remains in effect from this through 900 PM PST
Saturday. The high surf may cause beach erosion and will produce
life-threatening rip currents. Minor coastal flooding is possible
in low lying areas such as parking lots, especially near the times
of high tide, especially late this morning.

For west and northwest facing beaches south of Point Conception,
surf will average 8 to 12 feet today into tonight. Local sets to
15 feet are possible on exposed west facing locations such as
Ventura Harbor. High surf will slowly subside Saturday and
Saturday evening. A HIGH SURF ADVISORY remains in effect through
900 PM PST Saturday evening.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...High Surf Warning in effect until 9 PM PST Saturday for zones
      34-35. (See LAXCFWLOX).
     Winter Weather Advisory in effect from 6 PM this evening to 4
      PM PST Saturday for zone 38. (See LAXWSWLOX).
     Beach Hazards Statement in effect through Saturday evening
      for zone 39. (See LAXCFWLOX).
     Wind Advisory in effect until 10 PM PST Saturday for zone 39. (See LAXNPWLOX).
     High Surf Advisory in effect until 9 PM PST Saturday for
      zones 40-41-87. (See LAXCFWLOX).
     Winter Weather Advisory in effect until 4 PM PST Saturday for
      zones 52>54. (See LAXWSWLOX).
     Wind Advisory in effect from 10 PM this evening to 10 PM PST
      Saturday for zone 59. (See LAXNPWLOX).
PZ...Small Craft Advisory in effect until 3 AM PST Sunday for
      zones 645-670. (See LAXMWWLOX).
     Small Craft Advisory in effect until 3 PM PST this afternoon
      for zones 650-655. (See LAXMWWLOX).
     Gale Warning in effect until 9 PM PST Saturday for zones
      650-655-673-676. (See LAXMWWLOX).

&&

.HAZARD POTENTIAL OUTLOOK...(MON-FRI)
Strong winds are possible Thursday and Friday over the mountains
and southern Santa Barbara County. Snow and travel delays are
possible over the Tejon Pass/Grapevine area Thursday night into
Friday.

&&

$$

PUBLIC...Kittell
AVIATION...RAT
MARINE...RAT
BEACHES...RAT
SYNOPSIS...Sirard

weather.gov/losangeles

NWS LOX Office Area Forecast Discussion