Area Forecast Discussion
Issued by NWS Los Angeles, CA
FXUS66 KLOX 031723
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
923 AM PST Sat Dec 3 2016
A ridge of high pressure building east will put an end to the to
the Gusty Santa Ana winds this evening and support gradual
warming into Sunday. A deepening trough of low pressure will
likely bring cooler conditions with locally gusty north winds,
shifting northeast for the beginning to middle part of next week.
The Santa Ana winds were starting to diminish this morning, with
some areas having little if any winds such as the Ventura County
coast and interior valleys including the Santa Clara River Valley.
As a result, went ahead and cancelled the High Wind Warning for the
Ventura County mtns, VTU County interior vlys, and replaced the
warning with a Wind Advisory for the VTU County coastal vlys and
Santa Clarita Valley. Wind advisories will continue until early this
afternoon for the VTU County coastal vlys, San Fernando Vly, and
L.A. County coast from Malibu to the Hollywood Hills, where gusts up
to 45 mph can be expected. The wind advisories for the VTU County
coast, Catalina Island and San Gabriel vly were cancelled. Gusty
winds over 60 mph were still occurring in parts of the L.A. County
mtns including the Santa Monica range, so the High Wind Warnings
will continue there until early this afternoon. Please see the
latest Non-Precipitation Weather Message for further details on the
ongoing High Wind Warnings and Wind Advisories (LAXNPWLOX).
Otherwise, sunny and cool conditions will prevail across
southwestern CA today. Temps will be near normal to several degrees
below normal for most areas. Highs in the warmest coastal and vly
areas this afternoon will reach the mid 60s to around 70.
An upper level low over nwrn Mexico this morning will drift e thru
Sun. At the same time, upper level ridging over the eastern Pac will
extend into srn CA, with the ridge axis at its max over the area Sun
morning. The upper ridging will weaken Sun night, with broad upper
level troffiness expected to move into CA on Mon along with a
dissipating cold front into swrn CA.
Skies are expected to be mostly clear across the region tonight thru
Mon, except possibly some marine layer low clouds may develop along
the L.A./VTU County coast by Mon morning as an eddy forms over the
SoCal bight. Patchy low clouds and fog may develop in the Salinas
River Vly later Sun night into Mon morning as well.
Gusty ne winds will continue tonight and Sun morning, especially in
the favored areas of VTU/L.A.Counties, but be mostly below advisory
levels. Gusty n canyon winds should affect the SBA County mtns and s
coast Sun night, with gusty nw winds in the L.A./VTU County mtns
along the I-5 corridor, and gusty w to nw winds in the Antelope
Vly, which may linger into Mon morning.
Temps are forecast to warm to several degrees above normal for many
areas Sun before cooling to near normal to slightly below normal on
Mon. Highs in the warmest coast and vly areas will be in the 70s on
Sun, and mid 60s to around 70 on Mon.
***FROM PREVIOUS DISCUSSION***
The trof will continue to deepen slightly Tuesday and will bring
some additional cooling to most areas. Increasing northwest across
the outer waters should help an eddy develop over the SOCal bight
allowing for some low clouds to develop across the LA County coast
and possibly as far north as Oxnard. But NW winds across SBA
County should keep low clouds to the south. Most areas will be down
about 5 degrees from Monday. Then turning warmer Wed-Fri as weak
ridging and offshore flow return. The tail end of a cold front may
just brush the Central Coast Friday afternoon but precip should
remain north of SLO County.
At 1615Z, there was no marine inversion at KLAX.
Overall, high confidence in VFR conditions for all sites through
the TAF period. Moderate confidence in wind forecast through this
afternoon. Gusty north to northeast winds will impact the Ventura
and Los Angeles counties sites with surfacing winds as well as
LLWS and turbulence.
KLAX...high confidence in VFR conditions through TAF period. There
is a 15% chance of north winds around 10 knots through 20Z. Some
LLWS will be likely across the area through early this afternoon.
KBUR...high confidence in VFR conditions through TAF period.
Northerly winds will likely surface through early this afternoon.
For the Outer Waters, moderate to high confidence in current
forecast. Moderate confidence in Small Craft Advisory (SCA) level
northeasterly winds across PZZ676 through this afternoon.
Otherwise, winds will flirt with SCA levels through Sunday (with a
20% chance of a SCA being needed). On Monday and continuing
through Wednesday, SCAs will be needed as northwest winds increase
and seas build.
For the Inner Waters, moderate confidence in current forecast. For
the waters north of Point Sal, winds are expected to remaining below
SCA levels through Wednesday, but seas will build to SCA levels on
Sunday and Monday. For the waters south of Point Conception, SCA
level northeast winds are expected (moderate confidence) through
this afternoon from Ventura southward. From tonight through
Wednesday, winds and seas are expected to remain below SCA levels.
.FIRE WEATHER...03/600 am.
No changes expected for the current coverage of Red Flag Warnings,
which go through 6pm this evening for the Los Angeles and Ventura
County Valleys and Coasts. The Los Angeles County Mountains will
start at 6am this morning due to higher humidities and colder
conditions, but they will experience elevated risks with the
strong winds until then. The Ventura County Mountains will also
see elevated risks, but any Red Flag Conditions will be localized
and for a short duration.
Though much of the area has received around 1 inch of rain over
the last two weeks, the vegetation (fuels) remain receptive to
large fire growth under red flag weather conditions.
Those handling potential fire ignition sources must exercise
extra caution as extreme fire behavior and rapid fire growth is
expected if any fire were to be started. This includes those
lighting fires for warmth considering the cold conditions.
CA...Wind Advisory in effect until 2 PM PST this afternoon for
zones 41-45-88-547. (See LAXNPWLOX).
High Wind Warning in effect until 2 PM PST this afternoon for
zones 46-54. (See LAXNPWLOX).
Red Flag Warning in effect until 6 PM PST this evening for
zones 240-241-244>246-254-288-547-548. (See LAXRFWLOX).
PZ...Small Craft Advisory in effect until 2 PM PST this afternoon
for zones 650-655-676. (See LAXMWWLOX).
.HAZARD POTENTIAL OUTLOOK...(MON-FRI)
No significant hazards expected.