Area Forecast Discussion
Issued by NWS Los Angeles, CA

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FXUS66 KLOX 202341

Area Forecast Discussion
National Weather Service Los Angeles/Oxnard CA
441 PM PDT Wed Mar 20 2019

Updated Aviation Discussion

.SYNOPSIS...20/117 PM.

Today and tonight will be cloudy with scattered showers, mountain
snow, and a chance of thunderstorms. Showers and mountain snow
could linger into Thursday morning. The next chance for rain comes
Friday night into Saturday morning. Expect cooler than normal
temperatures for the period, with near normal temperatures
expected early next week.


.SHORT TERM (TDY-SAT)...20/140 PM.

Showers continue this afternoon, especially inland from the
beaches as winds have shifted to the west and convergence lines
are setting up mostly along topographical boundaries. And in
extreme southeast LA County a sharp convergence line with heavy
rain and hail continues from around Carson east to the Orange
County line. Can`t rule out showers in other areas through early
evening but focus is definitely more towards the valleys,
foothills, and mountains. Once we get into the evening hours
activity is expected to rapidly diminish with basically dry
conditions overnight except for possibly a few light showers over
the mountains.

On Thursday a weaker system will come through the area. This one
is much more stable with primarily west to northwest flow so
shower chances will be highest along the Central Coast, the
mountains, and in southeast LA County. Amounts expected to be
under a quarter inch with no thunderstorms.

Dry and warmer Friday as a little ridge develops.

On Saturday another weak system is expected to pass through but
again favoring just northern areas. Most model solutions keep rain
north of Pt Conception and very light.

.LONG TERM (SUN-WED)...20/152 PM.

Sunday another ridge develops with a light offshore gradient so
temps expected to warm up a few degrees.

Another system brewing out over the Pacific is poised to move
onshore along the west coast early next week, but the models are
disagreeing on how strong the ridge ahead of it will be and this has
an impact on how far south the clouds and rain chances will
reach. The GFS is the wetter solution, spreading light rain as far
south as LA County by Wednesday. The ECMWF keeps most of it
mainly north of Pt Conception. Seems prudent given the pattern to
go with at least a slight chance most areas, though again amounts
will be insignificant.



At 23Z, there was no marine layer.

TSRA will be possible through 03Z over Los Angeles County away
from the immediate coast, then moderate confidence that the
convective threat will end. Low confidence in how clouds evolve.
Chance for SHRA again on Thursday, but much less active and
intense as today.

KLAX...Low confidence in TAF. Conds will vary frequently, but
should be mostly MVFR this evening and tonight.

KBUR...Low confidence in TAF. Conds will vary frequently, but
should be mostly MVFR this evening and tonight.


.MARINE...20/1142 AM.

For the Outer Waters, moderate to high confidence in current
forecast. Small Craft Advisory (SCA) level south winds across
zones PZZ670/673 are over. SCA conds are not expected today
across the southern outer waters.

Across all of the outer waters, there is a 30-40% chance of SCA
level NW winds Thu afternoon and evening, then a 50% chance of SCA
level winds Sat thru Sun.

For the Inner Waters north of Point Sal, moderate to high
confidence in current forecast. SCA level south winds are over.
There is a 30-40% chance of SCA level NW winds Thu afternoon and
evening and again Sat afternoon and evening.

For the Inner Waters south of Pt Conception, moderate to high
confidence in current forecast with conds remaining below SCA
levels through Sun. However, there is 30-40% chance of SCA level
West winds Sat afternoon and evening.

There will be the threat of isolated thunderstorms across all the
coastal waters today. Gusty and erratic winds, brief moderate to
heavy rainfall and dangerous lightning will be possible.
Additionally, there is the potential for isolated waterspouts.


.BEACHES...20/1206 PM.

A relatively large, long period WNW swell will affect the coastal
waters today. Due to the west component of this swell, high surf
is also possible south of Point Conception. The breakers are
expected to rise to just above 10 feet on the Central Coast and
around 4-7 feet south of Point Conception. Surf will be highest
on west facing beaches.


CA...High Surf Advisory in effect until 11 PM PDT this evening for
      zones 34-35. (See LAXCFWLOX).
     High Surf Advisory in effect until 3 PM PDT Thursday for
      zones 40-41-87. (See LAXCFWLOX).



High surf and dangerous rip currents are expected over the



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