Pasadena, California Weather Forecast Discussion

571
FXUS66 KLOX 280710
AFDLOX
Area Forecast Discussion...UPDATED
National Weather Service Los Angeles/Oxnard CA
1210 AM PDT Sun Sep 28 2025
.SYNOPSIS...27/116 PM.
Cooler than normal conditions will persist through at least the
middle of next week with a deep marine layer and periods of
drizzle. Showers and thunderstorms are possible this afternoon,
mainly in the mountains, with light rain possible along the
Central Coast around Tuesday.
&&
.SHORT TERM (TDY-TUE)...27/849 PM.
***UPDATE***
Most of the shower activity has ended this evening as daytime
heating is lost. A few showers remain over eastern Los Angeles
County. A cut-off trough of low pressure is currently centered
over the Mojave Desert, and this trough will likely continue to
slowly move east into Arizona. A deep marine layer depth will
remain in place for tonight and into Sunday morning. Night through
morning low clouds and fog will remain in the forecast tonight
along with the possibility of night through morning drizzle.
***From Previous Discussion***
With the low moving into AZ Sunday and less instability and
moisture available the threat of showers and storms across the
mountains is much lower than today.
Another deep marine layer is expected Sunday and Monday mornings,
likely between 3000 and 4000 feet again with the possibility of
drizzle or light rain across coast, valleys, and lower coastal
slopes. Temperatures will again be 6-12 degrees below normal with
very slow, if any clearing of the stratus.
Later in the day Monday into Tuesday a trough along the West
coast with an unseasonably cold 530dam low just west of the
Pacific northwest coast will push onshore along the Central
Coast. Models have scaled back from earlier solutions but there
are still quite a few indicating light rain amounts, mainly under
a tenth of an inch across northwest SLO County with the southern
extent of any precip no farther than about Santa Ynez.
.LONG TERM (WED-SAT)...27/112 PM.
Dry conditions are expected Wednesday and likely through next
weekend with slowly warming temperatures that should get back to
near normal by Friday or Saturday. The one caveat is there are a
small percentage of solutions from the GEFS that continue to show
some upper level vorticity from Nardo getting picked up from the
advancing trough off northern California and reaching southern
California on Thursday. That is accompanied by a small wedge of
increased moisture aloft. With most of the ensemble solutions
keeping Nardo well west of the area there are currently no chances
for rain or storms locally, but it`s worth keeping an eye on.
&&
.AVIATION...28/0710Z.
At 0618Z at KLAX, the marine layer was 3400 ft deep. The top of
the inversion was around 5000 feet with a temperature of 17 C.
Overall, low to moderate confidence in TAF package. Timing of
flight cat changes may be off by +/- 2 hours, and flight cats may
be off by one cat at times through the period. Due to high clouds
cigs may scatter and reform frequently.
KLAX...Moderate confidence in TAF. Timing of flight cat changes
may be off by +/- 2 hours, and flight cats may be off by one cat
at times through the period. There is a 30% chance for an east
wind component reaching 8 kts from 10Z to 18Z Sunday.
KBUR...Moderate confidence in TAF. Timing of flight cat changes
may be off 2 hours. There is a 30% chance of BKN006-BKN009
conditions from 08Z to 16Z Sunday.
&&
.MARINE...27/852 PM.
Winds and seas are likely to remain below Small Craft Advisory
(SCA) levels for all coastal waters through Wednesday. There is a
30% chance of SCA wind developing Wednesday night for the central
and southern outer waters as well as the western portions of the
Santa Barbara Channel. Thereafter, chances for winds & seas to
reach SCA levels increases significantly - details will be ironed
out with future updates.
Seas are expected to remain below SCA levels through at least
Tuesday. Sunday into early next week, a southerly swell of 4 to 6
feet will impact the coastal waters and may produce issues for
exposed south facing harbors.
&&
.LOX WATCHES/WARNINGS/ADVISORIES...
CA...Beach Hazards Statement in effect from 6 AM PDT this morning
      through Wednesday afternoon for zones
      87-340-346-354-362-366. (See LAXCFWLOX).
PZ...NONE.
&&
$$
PUBLIC...Hall/MW
AVIATION...Schoenfeld
MARINE...Phillips/Black
SYNOPSIS...MW/RK
weather.gov/losangeles
Experimental Graphical Hazardous Weather Outlook at:
https://www.weather.gov/erh/ghwo?wfo=lox

NWS LOX Office Area Forecast Discussion