Scientific Forecaster Discussion
fxus66 klox 231551
Area forecast discussion...updated
National Weather Service Los Angeles/Oxnard California
851 am PDT Tue Oct 23 2018
Cool temperatures will continue through Wednesday. Offshore flow
and warmer conditions are expected by late in the week. Night
through morning low clouds and fog will return to some coastal
through Wednesday. Then, fair skies will remain through the
Short term (tdy-thu)...23/851 am.
Another mostly sunny and warm October day on tap for our area. No
impactful changes to the previous short term forecast. Visibility
is still only about a half mile near Paso Robles in fog that
pushed down from the north. Paso should clear by around 10 am and
the rest of the low clouds should be cleared to the coast by
around 11 am.
***From previous discussion***
Today will be the coolest day of the week as hgts reach their
minimum with the passage of a weak trof. The marine layer is 1500
ft deep. The low clouds have not formed as well as they did last
night due to the high clouds overhead, the offshore flow from the
north and only weak onshore flow to the east. The high clouds will
move out of the area in a few hours and by the time the low clouds
dissipate skies will be sunny everywhere. Max temps will fall 2 to
4 degrees from ydy but will still be a few degrees above normal.
Another sundowner is on tap tonight and the north to S push from both
the smx-sba and the bfl-sba gradients will be a little stronger.
This will bring borderline advisory level winds to more of the
canyons across the sba South Coast. The slight increase in the
north offshore flow will keep the low clouds out of all areas xcp
the southernmost portion of the la County coast.
A weak ridge moves into the state on Wednesday. The minimal marine
layer, offshore flow and increasing hgts will kick off a warming
trend. Under sunny skies Max temps will rise 2 to 4 degrees and
will end up 3 to 6 degrees above normal.
The warm up will start in earnest on Thursday as an east pac ridge
noses into the state. Offshore flow will continue it will be
strongest from the north. There will be no marine layer stratus
and under sunny skies Max temps will rise another 1 to 2 degrees.
Long term (fri-mon)...23/334 am.
Both the ec and GFS agree that the ridge will peak on Fri and Sat
and then break down Monday and Tuesday. Friday will be the warmest
day across the coasts and vlys due to the best combination of
offshore flow and hgts. There will be a few degrees of cooling
across the coasts and vlys on Saturday but the inland areas will
continue to warm as hgts rise. Max temps on Friday will be in the
upper 80s and lower 90s across most of the coastal and Vly areas
and will end up 10 to 15 degrees above normal. These readings
while very warm are not near record values. The offshore flow will
ensure the absence or marine layer clouds for the two day period.
Cooling on Sunday and then more cooling on Monday as the ridge is
knocked down by a pac northwest upper low and more importantly strong
onshore trends. Look for 3 to 6 degrees of cooling on Sunday and
an additional 4 to 8 degrees on Monday where Max temps will
collapse to near normal. Marine layer stratus will make a slow
come back mainly near the southern section of the la County coast.
At 1215z, the marine layer at klax was around 1400 feet deep. The
top of the inversion was 3300 feet with a temp of 20 degrees c.
Areas of low clouds were affecting the Central Coast, Coastal
Sections of l.A. County, and the San Gabriel, Santa Ynez and
Salinas valleys this morning. Conds were mostly IFR to LIFR,
except MVFR across coastal sections of l.A. County. Skies should
clear by mid morning in the valleys and by late morning on the
coastal plain. Expect low clouds to be confined to coastal
sections of l.A. County and possibly portions of the central coast
tonight with mostly IFR conds expected. Gusty north winds across
southern sba County this evening could bring some local low level wind shear and
Klax...moderate confidence in the 12z taf. There is a 20-30%
chance that cigs will slip into the IFR category between 12z and
15z this morning. There is a 20% chance that skies will clear as
early as 16z this morning. There is a 20% chance that cigs tonight
will not arrive until after 10z.
Kbur...moderate to high confidence in the 12z taf. There is a 20%
chance of IFR cigs between 12z and 15z this morning, and again
after 11z tonight.
For the outer waters, high confidence in current forecast. Small
Craft Advisory (sca) level northwest winds are likely thru Thu
night, although they may decrease below Small Craft Advisory levels at times. There
is a 40% chance of Small Craft Advisory conds Fri, then Small Craft Advisory are not expected Sat.
For the inner waters north of pt sal, moderate to high confidence
in current forecast. Small Craft Advisory level winds are expected this afternoon
and evening, and again Thu afternoon and evening. There is a
40-50% chance of Small Craft Advisory level winds Wed afternoon and evening.
For the inner waters south of pt Conception, high confidence in
current forecast with Small Craft Advisory conds not expected thru Sat. However,
there is a 30% chance of Small Craft Advisory level winds across the western half
of the sba channel late this afternoon and evening.
Pz...Small Craft Advisory in effect from 3 PM this afternoon to 9
PM PDT this evening for zone 645. (See laxmwwlox).
Small Craft Advisory in effect until 3 am PDT Friday for
zones 670-673-676. (See laxmwwlox).
Hazard potential outlook (thu-mon).
No significant hazards expected.