Nipomo, California Weather Forecast Discussion

073
FXUS66 KLOX 101111
AFDLOX
Area Forecast Discussion...UPDATED
National Weather Service Los Angeles/Oxnard CA
411 AM PDT Wed Sep 10 2025
Updated aviation and marine sections
.SYNOPSIS...10/1213 AM.
A period of cooler, well below normal temperatures will last at
least through the weekend. Morning marine layer clouds will
expand across coastal areas and many valleys with morning drizzle
possible through Friday, followed by a gradual warming trend for
the weekend.
&&
.SHORT TERM (TDY-FRI)...10/320 AM.
A unseasonably cool (569) upper low over Nrn CA will bring
increasing cyclonic flow, weak PVA and lowering hgts to Srn CA
today. The lift from the low has raised the marine layer to about
3600 ft, but it has also dramatically weakened the capping
inversion. Low clouds formed slowly and haphazardly early this
morning but now cover most of the csts and vlys (Sundowner winds
have kept the SBA south coast clear). The rapid deepening of the
marine layer has also brought drizzle to many areas. In a somewhat
surprising development clouds have formed across the interior
sections of SLO/SBA counties and the nrn VTA mtns as the trof
brought enough moisture with it to create clouds. Good clearing is
forecast this afternoon but there is a chc that some areas will be
partly cloudy with the lift and slight instability. There is also
a non zero (~10 percent) chc of a mtn shower as the trof rolls
overhead. The deeper marine layer and lowering hgts will bring
another 3 to 5 degrees of cooling to the area. Most cst/vly areas
will only see highs in the 70s with some lower 80s in the warmer
vlys today. This is 3 to 6 degrees blo normal for the csts and 6
to 12 degrees under normal for the vlys.
Most of the lift from the low will be gone tonight and tomorrow.
Marine layer stratus will slowly develop again, but by dawn most
of the csts/vlys will be covered with not-so-low clouds. Hgts
will be similar to today and max temps will not change much
either.
On Friday the upper low will slowly begin to shift to the east.
This will allow a weak ridge to move in from the west. The hgt
rises will not arrive early enough to lower the marine layer and
once again both the csts and vlys will wake up to a blanket of
marine layer clouds. By afternoon, however, the affects of the
incoming ridge will be felt as max temps will rise 2 to 4
degrees.
.LONG TERM (SAT-TUE)...10/1213 AM.
EC and GFS are in good agreement that weak ridging will hold sway
over the weekend. This will lead to a reduction in marine layer
clouds and a 2 to 4 degree bump up in temps. Sunday`s temps will
be very similar to Saturday`s. Max temps at the csts will range
from 70 to 80 and the vlys will come in at fairly comfortable 80
to 90 degrees. These vly max temps are 4 to 8 degrees blo normal.
The deterministic mdls part ways early next week with the GFS
developing an upper low over Nrn CA. The EC on the other hand
shows a weak trof on Mon and a weak ridge on Tue. The majority of
the ensembles generally follow the EC`s forecast as does the
official forecast. Skies should be clear save for the persistent
night through morning low clouds across most of the coasts (and
the Santa Ynez Vly). Max temps should not change much on Monday,
but will likely rise 2 to 4 degrees on Tuesday with max temps
coming in 2 to 4 degrees blo normal.
&&
.AVIATION...10/1059Z.
At 06Z, the marine layer depth was 1400 feet deep at KLAX. The
top of the weak inversion was 2100 feet with a temperature of 19
degrees Celsius.
Low-to-moderate confidence in the current forecast for coastal
and valley terminals. High confidence in the current forecast for
desert terminals. Lower confidence exists in the forecast timing.
Higher confidence exists in forecast for flight categories.
MVFR conditions will persist at most coastal and valley terminals
through at least 16Z. There is a moderate chance of IFR
conditions in any light rain or drizzle. MVFR conditions should
return after 02Z, or as late as 10Z.
KLAX...MVFR conditions are expected through at least 17Z, or as
late as 19Z. There is a 30 percent chance of IFR conditions in
drizzle through 16Z. There is a 50 percent chance of VFR
conditions with ceilings below 6000 feet continuing until at
least 19Z, or as late as 21Z. A return of MVFR conditions could
occur as soon as 03Z Thursday, or as late as 10Z Thursday. Any
southerly winds this morning should remain less than 10 knots.
KBUR...MVFR conditions are expected through at least 17Z, or as
late as 19Z. There is a 35 percent chance of IFR conditions in
drizzle through 16Z. There is a 50 percent chance of VFR
conditions with ceilings below 6000 feet continuing until at
least 19Z, or as late as 21Z. A return of MVFR conditions could
occur as soon as 07Z Thursday, or as late as 13Z Thursday. No wind
impacts are expected at this time.
&&
.MARINE...10/410 AM.
For the waters west through northwest of Point Sal including the
nearshore waters along the Central Coast, winds and seas should
remain below Small Craft Advisory (SCA) levels through at least
this afternoon. Local SCA level gusts are possible offshore of
Point Piedras Blancas this evening, but there is a moderate
(30-40 percent) chance of more widespread SCA level northwest
winds this evening. There is a likely (60-70 percent) chance of
SCA level northwest winds Thursday afternoon and evening and
lingering into at least Sunday. Brief lulls in the winds are
possible at times during the late night and early morning hours.
For the waters south through west of the Point Sal and outside
the southern California bight, there is a likely (60-80 percent)
chance of SCA level northwest winds through at least Sunday. The
highest chance of SCA level winds will occur between this evening
and Friday morning from around Point Conception south to San
Nicolas Island. Brief lulls in the winds are possible at times
during the late night and early morning hours.
Inside the southern California bight, there is a high-to-likely
(50-70 percent) chance of SCA level west winds each afternoon and
evening through Wednesday night, highest across the Santa Barbara
Channel, near Point Dume, and across the San Pedro Channel. For
late week, there is a moderate-to-high (30-50 percent) chance each
afternoon and evening through the remainder of the week.
&&
.LOX WATCHES/WARNINGS/ADVISORIES...
CA...Wind Advisory in effect until 5 AM PDT early this morning for
      zones 349-351. (See LAXNPWLOX).
PZ...Small Craft Advisory in effect from 1 PM to 9 PM PDT Thursday
      for zone 645. (See LAXMWWLOX).
     Small Craft Advisory in effect from 1 PM this afternoon to 3
      AM PDT Thursday for zone 650. (See LAXMWWLOX).
     Small Craft Advisory in effect from 1 PM Thursday to 3 AM PDT
      Friday for zone 670. (See LAXMWWLOX).
     Small Craft Advisory in effect until 3 AM PDT Friday for
      zones 673-676. (See LAXMWWLOX).
&&
$$
PUBLIC...Rorke
AVIATION...Hall
MARINE...Hall
SYNOPSIS...Schoenfeld
weather.gov/losangeles
Experimental Graphical Hazardous Weather Outlook at:
https://www.weather.gov/erh/ghwo?wfo=lox

NWS LOX Office Area Forecast Discussion