Cimarron, California Weather Forecast Discussion

659
FXUS66 KLOX 201804 AAA
AFDLOX
Area Forecast Discussion...UPDATED
National Weather Service Los Angeles/Oxnard CA
1104 AM PDT Sat Sep 20 2025
updated aviation discussion
.SYNOPSIS...20/156 AM.
A warming and drying trend will continue today. Isolated showers
cannot be ruled out over the mountains this afternoon, but drier
southwest flow should continue to stabilize the air mass. Monsoonal
moisture will begin to move north again on Sunday, and a return
of convective storms is possible as early as Sunday afternoon and
evening. Any shower activity for the coastal and valley areas
will likely delay until Tuesday.
&&
.SHORT TERM (TDY-MON)...20/320 AM.
The latest water vapor imagery indicates an upper-level ridge of
high pressure over the region this morning, while an upstream
cutoff trough sits off the California coast. The low cloud field
is pretty broken up due to a weak marine inversion in place, but
the most coverage of low clouds is along the Central Coast and
into the Santa Ynez Valley.
A drier southwest flow aloft will continue today across the
region. Marginal PoPs remain in the forecast over the western
portion of the Transverse Ranges due to just enough moisture in
place and some diffluence with the weak trough offshore. High
resolution multi-model ensemble members favor shower chances over
the Santa Barbara and Ventura County mountains this afternoon and
evening. People planning to travel mountain roads and/or
participate in outdoor activities today should be prepared for
brief heavy downpours, gusty and erratic winds, and dangerous
lightning.
Ridging aloft in place will bring a warming trend through the
weekend. Weak onshore flow with less cloud coverage will allow for
a slight warming trend to develop for the valley, mountain, and
desert areas. Closer to the coast, the onshore flow should inhibit
the bulk of the warming.
The latest model solutions and forecast ensembles continue to
indicate a surge of monsoonal moisture moving north between Sunday
and Tuesday. The moisture, associated with a tropical disturbance
off the Baja California coast, will be transported northward as
the weak cutoff trough off the coast approaches the coastline. The
cyclonic flow pattern will entrain some tropical moisture. PoPs
could increase as soon as Sunday. High resolution multi-model
ensemble members give a likely (60-70 percent) chance of
precipitable water values exceeding 1 inch by Sunday across
southern Los Angeles County. This agrees well with AI integrated
EPS ensemble members which increase PWAT values around to 1.1
inches at KLAX by Sunday afternoon, but the bulk of the moisture
looks to remain to the south until late Monday night or early
Tuesday morning. The PoP forecast for coastal and valleys areas
goes with NBM values for Sunday, but PoPs were increased across
the mountains and desert to account for isolated showers that
could pop up.
.LONG TERM (TUE-FRI)...20/320 AM.
The latest forecast ensembles increase precipitable water value
means through Tuesday to near 1.50 inches as the weak cutoff
trough slowly approaches the California coast. This should bring a
return of showers and thunderstorms to the area between Monday
night and Tuesday night as the moisture interacts with the
instability provided by the trough. A similar approach was
applied to PoPs for Monday through Wednesday, allowing for the
forecast for coastal and valley areas to go with NBM values, but
PoPs were increased across the mountains and desert to account for
increased convection over the areas.
The trough should pass by to the east for late week and bring some
warming and drying.
&&
.AVIATION...20/1802Z.
At 17Z at KLAX, the marine layer was 900 ft deep. The top of the
inversion was at 1400 ft with a temperature of 20 C.
High confidence in VFR TAFs for desert airfields (KWJF and KPMD).
Generally hi confidence for KPRB TAF as there is a 20% chance of
IFR/LIFR cigs/vsbys 12Z-16Z Sun, otherwise VFR conds are expected.
Overall, moderate confidence in remaining TAFs. Timing of
CIG/VSBY restrictions and flight cats may be off +/- 2 hours when
CIGs are present.
KLAX...Moderate confidence in 18Z TAF. There is a 40% chance of
IFR/MVFR cigs thru this afternoon. Otherwise, arrival and
clearing times of the low clouds may be off +/- 2 hours & there is
a 20%-30% chance of 003-004 LIFR CIGs after 09Z Sun through 15Z
Sun. No significant east wind component expected thru forecast
period.
KBUR...Moderate confidence in 18Z TAF. There is a 50% chc of IFR
cigs 14Z-17Z Sun. Otherwise, VFR conditions are expected through
forecast period.
&&
.MARINE...20/850 AM.
For the Outer Waters, moderate to high confidence in current
forecast. Through this morning, high confidence in winds and seas
remaining below Small Craft Advisory (SCA) levels. However, winds
may approach SCA levels south of Point Conception at times
tonight. For Saturday afternoon and evening, there is a 70% chance
of SCA level winds across PZZ673/676 and a 30% chance across
PZZ670. For Sunday through Tuesday, there is a 60-80% chance of
SCA level winds across all of the Outer Waters. For the rest of
the work week, moderate chances each afternoon & evening likely
focused south of Point Conception.
For the Inner Waters north of Point Sal, moderate to high
confidence in current forecast. Through today, high confidence in
winds and seas remaining below SCA levels, except for the far NW
portion of PZZ645 where there is a moderate chance of SCA level
wind gusts during the late afternoon/eve hours today. For Sunday
through Tuesday, there is a 30-40% chance of SCA level winds in
the afternoon and evening hours. On Wednesday, Good confidence in
winds and seas remaining below SCA levels.
For the Inner Waters south of Point Conception, moderate to high
confidence in current forecast. There is a 60% chance of SCA level
winds during the late afternoon/eve hours today across the
western/southern portions of the Santa Barbara Channel and this
may last into the late night hours. Slightly lower chances on
Sunday. Low chc on Monday, before increasing to moderate Tuesday &
Wednesday. Otherwise across the southern Inner Waters, Good
confidence in winds and seas generally remaining below SCA levels
through Monday.
Although there is a spread in model solutions, the general
consensus is that a closed upper low will draw tropical moisture
over the coastal waters early next week. Rain chances could begin
over far southern portions of PZZ655/676 Sunday afternoon, but as
of now coverage looks to be limited.
For Monday & Tuesday, widespread showers with the potential for
thunderstorms is possible across the coastal waters, with the
highest impacts likely south of Point Conception.
&&
.LOX WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
PZ...Small Craft Advisory in effect from 6 PM this evening to 3 AM
      PDT Sunday for zone 650. (See LAXMWWLOX).
     Small Craft Advisory in effect from 3 PM this afternoon to 9
      AM PDT Sunday for zones 673-676. (See LAXMWWLOX).
&&
$$
PUBLIC...Hall
AVIATION...Sirard
MARINE...Black/Sirard
SYNOPSIS...Hall
weather.gov/losangeles
Experimental Graphical Hazardous Weather Outlook at:
https://www.weather.gov/erh/ghwo?wfo=lox

NWS LOX Office Area Forecast Discussion