Area Forecast Discussion
Issued by NWS Los Angeles, CA

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000
FXUS66 KLOX 232058
AFDLOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
1258 PM PST Mon Jan 23 2017

.SYNOPSIS...
There will be showers with a chance of thunderstorms and gusty winds
into this evening. There may still be a chance of showers early Tuesday.
The temperatures should stay below normal into midweek...then
skies will become fair by midweek with normal temperatures over
the weekend in offshore flow.

&&

.SHORT TERM...(TDY-THU)

Cold, unstable air mass generating lots of showers and some
thunderstorms with small hail. Coverage has generally decreased
from this morning but we`re just now getting to the most unstable
period so there`s still a chance that areal coverage of precip
could increase through the afternoon. Showers are moving quickly
so even if in heavier showers and thunderstorms the likelihood of
flash flooding is fairly small, though not zero, and the watch
will continue through 6pm.

The next system currently just of the southern Oregon coast will
continue to slide south overnight and be off the Central Coast
Tuesday. Models keep most of the pva well offshore but enough
moisture to the east to at least keep some chance of showers in
the forecast for the western part of SLO/SB counties. Further east
into Ventura and LA Counties just some clouds but probably no
rain. Another cool day though with highs mostly in the 50s for
coast/valleys and 20s/30s in the mountains.

A ridge will start to build in from the west Tuesday night that
will initiate a slow warming trend through the end of the week.

.LONG TERM...(FRI-MON)

The warming trend will continue into the weekend as we transition
to offshore flow and likely some Santa Ana winds. Latest GFS is
showing 40-50kt of northeast wind at 850 late Friday into Saturday
then somewhat weaker winds Sunday. LAX-DAG gradients peaking at
around -7 mb which is pretty healty, especially for the GFS this
far out. At this point it`s safe to say that we should see at
least low end advisory northeast winds across portions of
LA/Ventura counties. Highs climbing up into the low 70s by Sunday.

Warmest day will probably be Monday as 950 temps rise into the low
20s (Celcius) and still some weak offshore flow in place.

&&

.AVIATION...23/1800Z.

At 1800z at KLAX...there was no marine inversion.

There is moderate confidence in the 18z TAFs. Frequent changes in
ceiling and visibility are still possible with conditions ranging
from MVFR to IFR through this evening. Conditions are not,
however, expected to change quite as much as yesterday. The
frequency and chance of showers or isolated thunderstorms is
expected to gradually decrease tonight.

KLAX... Only moderate confidence in the 18z TAF. Scattered
showers with mostly IFR/MVFR conditions through tonight with
frequent changes in CIGs and VSBYs especially near any
thunderstorms. Thunderstorms chances are ten to fifteen percent.
No east winds above 7 kts are expected during the forecast period.
VFR conditions will prevail after 08z.

KBUR... Only moderate confidence in the 18z TAF. Scattered
showers with mostly IFR/MVFR conditions through tonight with
frequent changes in CIGs and VSBYs especially near any
thunderstorms. Thunderstorms chances are ten to fifteen percent.
VFR conditions will prevail after 08z.

&&

.MARINE...23/200 PM.

Seas and swells are diminishing but will remain hazardous through
Tuesday. Breaking waves will continue over Morro Bay and Ventura
Harbor entrances as well as near the shoreline and breakwalls
through today. Small Craft Advisory level winds will continue
across most of the coastal waters through tonight and hazardous
seas will continue through Tuesday morning.

Moderate confidence in thunderstorms across the coastal waters
today.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...High Surf Advisory in effect until 9 AM PST Wednesday for
      zones 34-35-40-41-87. (See LAXCFWLOX).
     Flash Flood Watch in effect until 6 PM PST this evening for
      zones 34>41-44>46-51>54-59-87-88-547. (See LAXFFALOX).
     High Surf Advisory in effect until 6 PM PST Tuesday for zone
      39. (See LAXCFWLOX).
     Winter Storm Warning in effect until 6 PM PST this evening
      for zones 52>54. (See LAXWSWLOX).
PZ...Small Craft Advisory in effect until 6 AM PST Tuesday for
      zones 645-650-655-670-673-676. (See LAXMWWLOX).

&&

.HAZARD POTENTIAL OUTLOOK...(THU-MON)
Advisory level Santa Ana winds are possible across portions of
Ventura and Los Angeles counties from late Friday night through
Sunday.

&&

$$

PUBLIC...MW
AVIATION...Sweet
MARINE...Sweet
SYNOPSIS...STU

weather.gov/losangeles



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