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Area Forecast Discussion (AFD)

Issued by Los Angeles, CA (LOX)

                            
000
FXUS66 KLOX 212203
AFDLOX

Area Forecast Discussion
National Weather Service Los Angeles/Oxnard CA 
203 PM PST Thu Feb 21 2019

.SYNOPSIS...21/1233 PM.

A very cold storm system continues to move across the area this
afternoon bringing light to moderate rain, low elevation snow, 
and a chance of thunderstorms through early evening. Dry 
conditions will return on Friday through early next week, but 
below normal temperatures are expected for most areas.

&&

.SHORT TERM (TDY-SUN)...21/149 PM.

Showers and thunderstorms developing this afternoon under a very 
cold pool of air aloft. Amounts have been pretty light but
there have been multiple reports of small hail, graupel, and even
a few snowflakes down to around 1500'. Expect this to continue 
through the afternoon then start winding down in the evening as 
the air mass stabilizes. Upslope showers near the Grapevine will 
likely continue off and on through the overnight hours but with 
minimal additional accumulation. 

After the clouds and showers dissipate we'll see temperatures
falling to near or below freezing across many of our valleys and
some areas closer to the coast as well. The earlier Freeze Watch
has been converted to a Freeze Warning.

Pretty quiet weather Friday and through the weekend. Temps
remaining well below normal but warming a degree or two each day.

.LONG TERM (MON-THU)...21/202 PM.

Quiet weather through the period as a ridge of high pressure
develops along the west coast. Temps will warm a a degree or two 
each day reaching close to normal by Tue/Wed and possibly even
slightly above normal Thu.

&&

.AVIATION...21/1826Z.

At 1800Z, there was no marine inversion at KLAX.

Overall, moderate confidence in 18Z TAF package. Cold and 
unstable air mass will bring VFR CIGs and a chance of showers to 
all sites through this evening. There is a 30% chance of MVFR CIGs
in association with any shower activity. There is a 10-15% chance
of TSTMs through early this evening for all sites. Any TSTMs 
would be capable of producing gusty/erratic winds and small hail.

KLAX...Moderate confidence in 18Z TAF. There is a 20-30% chance 
of MVFR CIGs and light showers through 02Z. Additionally, there is
a 10% chance of TSTM through 02Z. 

KBUR...Moderate confidence in 18Z TAF. There is a 20-30% chance 
of MVFR CIGs and light showers through 02Z. Additionally, there is
a 10% chance of TSTM through 02Z.

&&

.MARINE...21/1023 AM.

For the Outer Waters, moderate to high confidence in current 
forecast. High confidence in strong Small Craft Advisory (SCA) 
level northwest winds through tonight for all Outer Waters with
local gusts reaching GALE force this morning. On Friday, there is
a 70% chance of SCA level northwest winds continuing into the 
evening. For Saturday through Monday, there is a 50% chance of SCA
level winds on Saturday afternoon/evening for PZZ673/676.
Otherwise, winds and seas are expected to remain below SCA levels. 

For the Inner Waters north of Point Sal, high confidence in 
current forecast. There is a 70% chance of SCA level northwest
winds this afternoon and evening. For Friday through Monday, winds
and seas are expected to remain below SCA levels. 

For the Inner Waters south of Point Conception, high confidence 
in current forecast. SCA level west to northwest winds will
continue through mid-afternoon today, before diminishing with the
strongest winds across western sections. For tonight through
Monday, winds and seas are expected to remain below SCA levels. 

For all waters, there is a slight chance of thunderstorms through
this evening. Gusty/erratic winds, small hail, waterspouts and
steep seas will be possible with any thunderstorms.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...Freeze Warning in effect from midnight tonight to 8 AM PST
      Friday for zones 34>36-44>46-88-547. (See LAXNPWLOX).
     Winter Weather Advisory in effect until 10 PM PST this
      evening for zones 37-38-51>54-59. (See LAXWSWLOX).
PZ...Small Craft Advisory in effect until 9 PM PST this evening
      for zones 645-650-655. (See LAXMWWLOX).
     Small Craft Advisory in effect until 3 AM PST Friday for
      zones 670-673-676. (See LAXMWWLOX).

&&

.HAZARD POTENTIAL OUTLOOK (SUN-THU).

No significant hazards expected.

&&

$$

PUBLIC...MW
AVIATION...RAT/Sweet
MARINE...RAT/Sweet
SYNOPSIS...Stewart

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