Area Forecast Discussion
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FXUS66 KLOX 251236
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
536 AM PDT Tue Apr 25 2017
Gusty northwest to north winds will likely continue through the
work week for portions of Southwest California with weak to
moderate offshore winds possible by this weekend. A gradual
warming trend is expected for most areas through this weekend.
There were plenty of low clouds on northern and interior mountain
slopes, interior sections of SLO and SBA Counties, the Santa Ynez
Valley and southern portions of the Central Coast. There could be
a few light showers embedded in these clouds which could affect
northern slopes this morning. Otherwise, areas of high clouds
were drifting across the region early this morning. Any low clouds
should clear by late morning, with partly cloudy skies this
afternoon. Gusty nw to n winds continue across the Interstate-5
Corridor, southern Santa Barbara County through and below passes
and canyons, the Santa Clarita Valley, and the Antelope Valley
this morning, and wind advisories in all those areas look good.
Expect advisory level northwest winds once again on the Central
Coast this afternoon and evening. Locally gusty north winds will
affect the San Fernando Valley, the valleys of VTU County and the
Santa Monica mountains.
An upper low was located in Wyoming with a trough extending
southwestward into the Great Basin. There was broad cyclonic
northwesterly flow across the forecast areas. Max temps
should edge upward a few degrees today as heights and thicknesses
rise slightly. Expect areas of low clouds on northern slopes and
across interior sections of SLO and SBA County, and possibly
across the Santa Ynez Valley and portions of the Central Coast
tonight/Wed morning, with mostly clear skies elsewhere. Winds
should decrease below advisory levels on the Central Coast this
evening, across the Antelope Valley late tonight, and across
southern SBA County and the Santa Clarita Valley Wed morning.
However good N-S grads and decent nw winds aloft should make
for windy conditions again Wed afternoon or evening into Thu
morning. Wind advisories will likely be needed again on the
Central Coast Wed afternoon, and southern SBA County and
the Santa Clarita Valley Wed evening into Thu morning. Rising
heights and thicknesses should lead to several degrees of warming
in most areas on Wed.
An upper low will drop into Montana Wed night and Thu.
This will cause northwesterly flow aloft to increase across the
region Thu, and any lull in the winds Thu morning should be
brief. Additional wind advisories will likely be needed Thu.
Max temps should be down a few degrees in most areas Thu.
There may be a bit more in the way of stratus Wed night/Thu
morning north of Pt Conception, and plenty of clouds are
expected on northern slopes with a slight chance of showers there
late Wed night into Thu morning
The upper low will drop into Utah on Fri, with fairly strong nw
flow aloft over the forecast area and continued steep N-S
gradients. Gusty nw to n winds will continue to affect similar
portions of the region on Fri. Do not expect too much in the way
of stratus Thu night into Fri morning, especially south of Pt
Conception. Max temps on Fri should be up a few degrees in most
areas, mainly west of the mountains.
Height and thicknesses will rise over the weekend as an upper
ridge amplifies along the West Coast. Low level flow will
turn more northeasterly by Sat, and though low level flow will
weaken on Sunday, it will remain offshore, at least in the
morning. Expect max temps to jump Sat on, especially west of the
mountains, with highs likely in the lower 90s in the warmer valley
locations. There may be a few degrees of cooling across the
coastal plain on Sunday, especially near the coast, but it will be
very warm elsewhere. As the upper high begins to break down on
Monday, and flow turns onshore, expect cooling in coastal and
valley areas, with little change in temps in the mtns and deserts.
At 1130Z, there was no marine layer inversion to speak of around
KLAX early this morning.
Overall, VFR conditions are expected for most areas away from the
interior locations including the northern mountain slopes. There
will be MVFR patchy cigs in the vicinity of KSBP and KSMX through
17z this morning as well as KPRB. Northerly winds should keep MVFR
Cigs away from LA/VTU County Coastal and valley location over the
next 24 hours. There is a 50% chance that MVFR cigs could develop
around the Central Coast and interior areas later today through
tonight. Bands of ACSL were streaming across the leeward side of
the Tehachapi Mtns and could continue through this morning. There
will be some UDDF across the mountains and LLWS is expected
around KSBA later this afternoon, and KVNY through today.
KLAX...moderate confidence in 12Z TAF. There is a 20% chance of
MVFR CIGs 10z-15z Wed morning. High confidence in VFR conditions
KBUR...high confidence in 12Z TAF. There is a 30% chance of
LLWS/turbulence through 18z.
For the Outer Waters, high confidence in current forecast. Strong
northwest winds are anticipated to continue through the week.
Currently, a Gale Warning is in effect through late Wednesday
night. There is a 70% chance that Gale force winds will continue
For the Inner Waters, moderate confidence in current forecast. A
Gale Warning has been issued once again valid for this afternoon
for the inner waters south of Point Conception. Mainly affecting
the western portions. Otherwise, Strong Small Craft Advisory (SCA)
level winds are expected each afternoon/evening through Friday
with a 30% chance of Gale force wind gusts developing.Due to
strong winds throughout the waters, seas will be very choppy this
week, making for hazardous boating conditions through the week.
CA...High Surf Advisory in effect until 9 AM PDT this morning for
zones 34-35-40-41-87. (See LAXCFWLOX).
Wind Advisory in effect from noon today to 9 PM PDT this
evening for zones 34-35. (See LAXNPWLOX).
Wind Advisory in effect until 9 AM PDT Wednesday for zones
39-52-88. (See LAXNPWLOX).
Wind Advisory in effect until 9 AM PDT Thursday for zones
53-54. (See LAXNPWLOX).
Wind Advisory in effect until 3 AM PDT Wednesday for zones
59-87. (See LAXNPWLOX).
PZ...Small Craft Advisory in effect until 3 AM PDT Wednesday for
zone 645. (See LAXMWWLOX).
Gale Warning in effect from 3 PM this afternoon to 3 AM PDT
Wednesday for zones 650-655. (See LAXMWWLOX).
Gale Warning in effect until 3 AM PDT Thursday for zones
670-673-676. (See LAXMWWLOX).
.HAZARD POTENTIAL OUTLOOK...(THU-MON)
Gusty north to northwest winds are expected across southern Santa
Barbara County, the Central Coast, the I-5 corridor, and the
Antelope Valley. Advisory level winds expected at times in these
areas Thursday through early Friday, with local warning level
gusts. Elevated surf is possible on the beaches Thursday night
and Friday. Gusty northeast winds are possible across portions of
Los Angeles and Ventura Counties Saturday, with well above normal