Area Forecast Discussion
Issued by NWS Los Angeles, CA
FXUS66 KLOX 232102
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
202 PM PDT TUE AUG 23 2016
The temperatures will be near normal this week with mostly clear
skies...except for an overnight coastal marine layer. A low
should approach by Friday for a deeper marine layer and a cooling
trend into Saturday. Then a high will move in next week for less
clouds and a warming trend.
Marine clouds were slow to diminish from the Central Coast today
and a few swaths remain in the early afternoon. Other than that
the skies are clear of clouds though smoke from the Chimney and
Rey fires are clearly evident on visible satellite.
Temperatures across the region continue to be within a few
degrees of readings yesterday though slightly warmer at most
locations. High pressure over the region will strengthen a bit
more tomorrow and result in slightly warmer temperatures again. By
Thursday the influence of a passing trough will cool afternoon
temperatures into the weekend.
The primary weather focus of the day is regarding the winds in
Santa Barbara County and specifically along the south coast and
across the Rey Fire. Wind flow has been shifting to the north and
this will result in Sundowner winds developing again tonight.
Winds will be strongest today... three to seven miles per hour
greater than yesterday... then a bit weaker on Wednesday. The
strongest winds will occur along the coast between Gaviota and
Refugio State Beach with weaker winds to the east of Refugio.
Local gusts will tickle the bottom of advisory criteria but will
be in a relatively small stretch.
The bigger impact will be the transport of the smoke and ash from
the Rey Fire over the greater Santa Barbara area. The flow will be
northerly from the surface to up past the mountain ridges at 5000
feet so all of the output of the fire will be in the direction of
the population. This will continue into at least early Thursday.
The winds should weaken further on Friday and begin to shift from
the favored northerly flow.
Temperatures will begin to warm again by Sunday and continue to
warm by a few degrees each day into the work week. The marine
clouds will push the farthest into the valley areas on Saturday
then retreat to back along the coast by Monday and Tuesday.
Conditions remain dry.
At 1720Z, the marine layer was around 1000 feet deep at KLAX. The
top of the inversion was near 2700 feet with a temperatures of
around 22 degrees Celsius.
North of PT.CONCEPTION...Moderate confidence with IFR conds at
coastal TAF sites again tonight into Wednesday morning. KPRB is
low confidence whether fog will again reach the airfield.
South of Pt. Conception...low confidence that MVFR to IFR-
conditions will affect coastal TAF sites tonight into Wednesday
morning. There is high confidence in VFR conditions through
Wednesday in the valley TAFS. Gusty southwest winds will continue
in the Antelope Valley during the afternoon and evening.
KLAX...There is a 40 percent chance of VFR conditions through
KBUR...High confidence in VFR conditions through Wednesday.
A Small Craft Advisory remains in effect across the outer waters
from PT. SAL to NW of san nicolas Island including Cruz Island and
areas westward through late Wednesday night. There will be times
when gusts will be at sub advisory levels.
A Small Craft Advisory has also been issued for the western
portion of the Santa Barbara Channel inner waters from late this
afternoon through 3 am PDT Wednesday morning. Expect NW wind gusts
up to 30 kt west of Refugio. There is a 50% chance that another
SCA will be needed once again for the western portion of the SBA
Channel Wednesday afternoon through early Thursday morning.
.FIRE WEATHER...23/500 AM.
High pressure will begin to build in over SW California today.
This will help stabilize the air mass above 7000 to 1000 ft this
afternoon. and decrease plume fire behavior somewhat. The marine
layer will shrink allowing a slight increase in temperatures and
lower humidity. Winds aloft will remain weak but they align out
of the north today and Wednesday. This will lead to weak Sundowner
wind events for the south Santa Barbara coastal region mainly west
of Goleta and nearby Santa Ynez Range each evening. Northerly
winds over the Rey Fire will likely push smoke southward during
this period. Some relief in temperatures and humidity is expected
later in the week as a low pressure trough deepens over the
district. Expect stronger onshore winds for locally gusty winds
both Thursday and Friday.
PZ...Small Craft Advisory in effect until 3 AM PDT Wednesday For
zone 650. (See LAXMWWLOX).
Small Craft Advisory in effect until 3 AM PDT Thursday For
zones 673-676. (See LAXMWWLOX).