Area Forecast Discussion
Issued by NWS Los Angeles, CA
FXUS66 KLOX 261214
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
514 AM PDT Sun Mar 26 2017
...Aviation discussion updated...
Despite increasing clouds there will be a few degrees of warming
today. A weak trough on Monday may bring a few light showers over
San Luis Obispo and Santa Barbara counties as well as the north
slopes. Gusty north winds will begin Monday night and persist
into Tuesday. Weak ridging aloft will bring warm and dry
conditions for the middle of next week.
A fast moving ridge will move through the area today. It is not
strong enough to deflect the overrunning clouds in front a weak
frontal system to the NW so mid and high clouds will increase
today and all areas should be mostly cloudy by mid afternoon.
There is some low level moisture and it is turning to clouds as it
is lifted up the north slopes and also in the Santa Ynez vly
where west winds are helping lift the moisture up the hillsides.
Patchy stratus will also form over the LA coastal areas this
morning do to radiational cooling of the low level moist layer.
Despite the clouds the ridge will allow for a degree or two of
A weak trof and an even weaker front will graze the area on
Monday. It will make for a mostly cloudy morning. There is little
dynamics or low level moisture with this system and it will only
bring a chc of a light shower or two to SLO county and the north
slopes of the mtns. The clouds and the lower hgts assoc with the
trof will knock a few degrees off of the max temps. MAx temps will
end up 3 to 5 degrees blo normal.
The biggest weather concern for the next 7 days will start Monday
evening and last into Tuesday morning. Cool air advection and
quickly increasing sfc pressure gradients will combine with strong
N flow aloft to set up a potential for a very strong wind event.
A high wind watch has been posted for the SBA/VTA/LA mtns as well
as the Santa Clarita Vly and the SBA south coast. The VTA
vlys...The Santa Monica mtns...the Antelope Vly and the San
Fernando vly will also need wind advisories which will be issued
when the event draws nearer. Gusts to 60 mph are possible in the
watch area and gusts from 45 to 55 mph will be likely in the other
above mentioned areas.
The winds will decrease rather quickly and by late morning
Tuesday there will only be moderate winds. Aside from the
winds...it will be sunny as a strong 576 DM ridge pushes in. Max
temps will jump 4 to 8 degrees and most of the coasts and Vlys
will have above normal temps.
Both the EC and GFS that Wednesday will be the warmest day of the
next 7 as the ridge peaks with 580 DM hgts. The north flow will
switch to the NE and there will be sub advisory canyon winds in
the morning. max temps will be 8 to 12 degrees above normal with
almost all of the vly max temps in the 80s and the non beach
coastal areas in the mid 70s to lower 80s.
An inside slider will zip down the NV/CA state line Thursday it
will bring onshore flow and cooler conditions as well as setting
the stage for another north wind event Thursday night and Friday
Both mdls forecast a ridge for Friday its just the GFS forecasts a
very large one and the EC a small one. For now split the
difference and gave the forecast max temps in between the sort of
warm EC fcst and the hot GFS solution.
Mdls then go off on the own different ways for Saturday with the
GFS continuing the hot ridge solution and the EC bringing in a
much cooler inside slider. For now shaded forecast towards the
warmer GFS thinking.
At 09Z at KLAX... there was no notable inversion.
Overall at coastal locations... Moderate confidence in the
current TAFs. IFR/MVFR conditions through 18z are likely at Los
Angeles County sites and there is a thirty five percent chance at
the other coastal sites. VFR conditions will prevail after 18z
then MVFR conditions return after 08z on the Central Coast and
09z-13z south of Point Conception.
Overall at non-coastal locations... High confidence in the current
TAFs. There is a ten percent chance of IFR/MVFR conditions at
KBUR and KVNY 12z-17z. Otherwise and elsewhere VFR conditions
will prevail throughout the forecast period.
KLAX... Moderate confidence in the current TAF. IFR/MVFR
conditions through 18z are likely. VFR conditions will prevail
after 18z then MVFR conditions return after 13z. No east winds
above seven knots are expected.
KBUR... Moderate to high confidence in the current TAF. There is
there is a ten percent chance of IFR/MVFR conditions 12z-17z
otherwise VFR conditions will prevail.
For the Outer Waters... Small Craft Advisory (SCA) level winds
will continue through at least Monday morning. Gusts to 30 knots
and a few local gusts to 35 knots are possible between San Nicolas
and Santa Rosa Islands. Stronger northwest winds are likely by
late Monday morning and continuing through Tuesday and a Gale
Watch has been issued for that time period.
For the Inner Waters... There is a sixty percent chance of SCA
level winds across the western portion of the Santa Barbara
Channel by this afternoon and a thirty percent chance for the
inner waters of the Central Coast. There is a sixty five percent
chance of SCA level winds across all of the inner waters Monday
afternoon and Tuesday.
Winds will decrease across the coastal waters on Wednesday but
will remain elevated through at least Thursday.
CA...High Wind Watch in effect from Monday evening through Tuesday
morning for zones 39-52>54-88. (See LAXNPWLOX).
PZ...Small Craft Advisory in effect from 2 PM this afternoon to 11
AM PDT Monday for zone 650. (See LAXMWWLOX).
Small Craft Advisory in effect until 11 AM PDT Monday for
zones 670-673-676. (See LAXMWWLOX).
Gale Watch in effect from Monday morning through Tuesday
afternoon for zones 670-673-676. (See LAXMWWLOX).
.HAZARD POTENTIAL OUTLOOK...(TUE-SAT)
Strong and gusty north winds will affect the area into early
Tuesday, with the potential for damaging wind gusts especially in
the mountains. Travel will be impacted by the winds over a large
Another round of strong and gusty northwest to north winds will
be possible Thu night in the mountains and along the Santa Barbara
County south coast, with travel being affected by the winds.