812
FXUS66 KLOX 282057
AFDLOX

Area Forecast Discussion
National Weather Service Los Angeles/Oxnard CA
157 PM PDT Wed Oct 28 2026

.SYNOPSIS...28/225 AM.

Gradual cooling will continue through the week as will coastal
flooding issues due to very high tides. The next storm system is
expected to arrive late Friday or Saturday with rain chances
continuing into Sunday.

&&

.SHORT TERM (TDY-SAT)...28/130 PM.

Overall, 12Z models in good synoptic agreement through the short
term period. At upper levels, a low will continue to spin off the
Pacific Northwest coast with a sharp trough axis extending south.
At the surface, weak onshore flow will prevail through Saturday.

Forecast-wise, tonight through Friday afternoon, the weather
should be rather benign. With the upper level trough and weak
onshore flow, the marine inversion should remain rather deep and
marine layer stratus should become more widespread across the
coasts and coastal valleys. Additionally, there will be an
increase in mid and high level clouds, leading to a partly to
mostly cloudy sky conditions. As for precipitation chances through
Friday afternoon, there will likely be some patchy drizzle or
light marine layer showers across the area. However through Friday
afternoon, totals, if any, will be only be on the order of a few
hundredths of an inch. With the cloud cover and lowering
thicknesses, temperatures will exhibit a cooling trend through
Friday.

For Friday night and Saturday, an upper low will pinch off from
the parent trough, about 400 southwest of Point Conception. This
will set the stage for a wet Halloween weekend. Models continue to
exhibit some difference in the speed of this low moving eastward
towards northern Baja (the ECMWF is faster than the GFS). With the
afternoon forecast, will split the difference between the GFS and
ECMWF. So, will expect the rain chances to increase across all
areas during the day on Saturday. Given the current trajectory of
the low, the highest rain chances and totals through Saturday
evening look to occur across LA county. Preliminary totals
through Saturday evening are expected to range between 0.10 and
0.33 inches across the area.

.LONG TERM (SUN-WED)...28/130 PM.

For the extended, main storm action for the area looks to be
Saturday night and Sunday morning with rain chances diminishing
Sunday afternoon and evening. Based on model trends the last few
days, the highest rain totals are expected to remain south of LA
county. For our area, storm totals through Sunday are expected to
range between 0.50 and 1.50 inches for most areas with local
amounts up to 2.50 inches across south-facing mountain slopes.
Rainfall rates are expected to be in the 0.10 to 0.33 inch/hour
range. However, based on a continued wide range of solutions in
the ensemble members, there is moderate confidence at best in the
above numbers. There is a 20% chance of totals/rates double the
expected numbers and a 20% chance of totals/rates half of the
expected numbers. As for thunderstorm chances, the odds are pretty
low (10% or less) as the best instability is forecast to remain
south of LA county.

Once this storm moves eastward Sunday afternoon/evening, an upper
level ridge will develop over the area Monday and Tuesday. This
will bring dry and warmer conditions to the area. Additionally,
there will be some offshore flow at the surface, but the offshore
winds look to be on the weak side.

On Wednesday, the upper level ridge is nudged eastward as a low
tracks northeastward into northern California. This will likely
bring some increase in high-level clouds and some slight cooling
as offshore flow decreases. As for rain chances, models indicate a
low chance (less than 15%) of any showers across the area.

&&

.AVIATION...28/1703Z.

At 1600Z at KLAX, the marine layer was 3600 ft deep. The top of
the inversion was at 5700 ft with a temperature of 14 C.

High confidence in VFR TAFs for desert airfields (KPMD & KWJF).

Moderate confidence in remaining TAFs. SCT-OVC250 with chc
for VFR CIGs 030-50. MVFR CIGs 025-030 possible especially
earlier in fcst.

KLAX...Moderate confidence in TAF. SCT/BKN035-055 likely after
29/06Z. Any east wind component is expected to remain under 8 kt.

KBUR...Moderate confidence in TAF. SCT/BKN 030 possible after
29/06Z. No wind issues expected.

&&

.MARINE...28/802 AM.

Conditions are expected to remain below Small Craft Advisory (SCA)
levels through Friday. Southwest flow aloft will produce chances
for drizzle and isolated light rain showers Thursday and Friday.

A storm system is expected to impact the coastal waters this
weekend. There is a wide range of outcomes, but there is at least
a low threat of a 12-24 hour period of strong winds and steep
seas. Worst conditions look to be focused south of Pt Conception.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...Coastal Flood Advisory in effect until 2 PM PDT Friday for
      zones 87-340-346-349-350-354-362-366. (See LAXCFWLOX).
PZ...NONE.

&&

$$

PUBLIC...Thompson
AVIATION...Black
MARINE...Black
SYNOPSIS...MW

weather.gov/losangeles

Experimental Graphical Hazardous Weather Outlook at:
https://www.weather.gov/erh/ghwo?wfo=lox

NWS Los Angeles (LOX) Office