Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Los Angeles/Oxnard California
529 PM PDT Wednesday Aug 24 2016
Mostly clear skies...except for a coastal overnight marine
layer...breezy winds and normal temperatures into Thursday.
On Friday and Saturday a low should bring a deeper marine layer
and cooling trend. Then next week a high will bring less clouds
and a warming trend.
Afternoon temperatures in the mountains and in the San Fernando
Valley are four to six degrees warmer than yesterday but most
locations are within a couple degrees. The marine clouds are slow
to retreat from the central coast but are now clinging only to
favored coastal areas as well as to most of the The Channel
The forecast is on track for afternoon temperatures to peak today
then gently cool into the weekend. The marine incursion will
deepend and broaden its impact through this time period as well.
Friday night / Saturday morning should have the coolest
temperatures and with the marine clouds at their deepest incursion
into the coastal adjacent valleys.
Sundowner winds will set up again this evening and into the early
overnight period across the Santa Barbara South Coast and portions
of the adjacent canyons. The strength of the winds will be similar
to last evening... local gusts to 40 mph... though the duration
and areal extent of the strongest winds will be a bit less.
The northerly flow will again bring much of the smoke and ash
from the rey fire directly over the greater Santa Barbara area.
There is a hint of shifting a bit to the northwest by late tonight
and by tomorrow night the flow has a greater westerly component.
This will push the smoke more toward carpenteria and Ventura but
the strength of the wind will be greatly diminished by tomorrow
Winds had also kicked up in the I-5 corridor early this morning
but though there might be some weak gusts tonight... overall the
winds will be much gentler in that area overnight.
The weekend will begin cool and with a push of the marine clouds
into coastal adjacnet valleys. By Sunday afternoon... temperatures
will begin to warm again and marine clouds will retreat. Monday
and Tuesday will have above normal temperatures but not
particularly hot as weak high pressure builds over the region.
Another broad low pressure trough begins to nudge into the region
by late Tuesday and temperatures should begin to cool once again.
Overall a fairly quiet weather pattern.
At 00z, the marine layer was 800 feet deep at klax. The top of
the inversion was near 4000 feet with a temperature near 23
North of Point Conception...high confidence in LIFR conditions
returning this evening, likely returning between 02z and 08z.
There is a chance of vlifr conditions at all coastal terminals
South of Point Conception...moderate confidence in IFR conditions
for coastal terminals after 08z. Periods of wind shear and
turbulence are possible at ksba between through 08z.
Klax...low confidence with timing and moderate confidence with MVFR
conditions after 08z tonight. Otherwise, VFR conditions will
persist. Low clouds should scour out within an hour of 00z taf
Kbur...high confidence in VFR conditions throughout the period.
There is a 10 percent chance of IFR conditions after 10z.
A Small Craft Advisory remains in effect across the outer waters
from Point Sal to San Clemente Island and areas westward through
early Thursday morning. There will be times when gusts will be at
sub advisory levels.
A Small Craft Advisory for the east Santa Barbara Channel also
remains in effect for the western portion of the sba channel from
late this afternoon through early Thursday morning.
A short-period wind swell will create choppy sea at times across
the entire coastal waters into tonight.
Weak high pressure aloft will be the primary influence on our
fire weather conditions for another night before a low pressure
trough begins to develop over the state Thursday to bring cooler
temperatures. In the meantime, the current weather pattern will
support another evening and night of weak to moderate sundowner
conditions across the Santa Barbara South Coast, primarily west of
Goleta and the adjacent hills of the Santa Ynez Range. Peak winds
will be similar to Tuesday night's winds with peak gusts in the
windiest canyons around 40 mph. Relative humidity values will
again be between 20 and 30 percent through the windiest areas. The
overall synoptic flow pattern will also once again support some
gusty north and northwest winds tonight from the I-5 corridor
westward into the eastern Santa Barbara mountains. Winds could
gust as high as 30 to 35 mph through this area, although near the
rey fire these wind speeds will be restricted primarily to the
ridgetops. This northerly flow will continue to push any smoke
from the rey fire southward over Santa Barbara and Montecito this
evening and tonight.
As the low pressure develops over the state, expect some relief in
temperatures and humidity Thursday and Friday. This weather
pattern will eliminate any sundowner chances, help push any
wildfire smoke in the area to the east, while producing stronger
onshore winds for locally gusty west and southwest winds both
Thursday and Friday through areas such as the highways 14 and 138
corridors. High pressure begins to rebuild over the state this
weekend and will peak early next week. This pattern will result in
a return to above normal temperatures for all but the immediate
coastal area and a broad extent of minimum relative humidities
less than 20 percent.
Pz...Small Craft Advisory in effect until 3 am PDT Thursday for
zones 650-673-676. (See laxmwwlox).