Griffith Park, California Weather Forecast Discussion

335
FXUS66 KLOX 200547
AFDLOX
Area Forecast Discussion...UPDATED
National Weather Service Los Angeles/Oxnard CA
1047 PM PDT Fri Sep 19 2025
.SYNOPSIS...19/1231 PM.
A moist air mass remains in place over the region today but
convective storms will become primarily confined to the mountains
and desert. Expect some drying on Saturday, but monsoonal
moisture will begin to move north again on Sunday and a return of
convective storms is possible for the coastal and valley areas
early next week.
&&
.SHORT TERM (FRI-MON)...19/806 PM.
***UPDATE***
The area slowly dried out today and the csts/vlys slowly cleared
with most of those area seeing sunshine by mid afternoon. The
interior remained cloudy through the day although the clouds are
on the downswing now. The afternoon sunshine warmed may areas 2 to
3 locally 5 degrees. Cstl temps were 1 to 3 degrees blo normal and
the vlys were 4 to 8 degrees cooler than normal.
The area of best instability was well to the east of the area and
there were no TSTMs and barely any showers over the mtns this
afternoon.
The marine inversion was pretty disrupted earlier today but the
low clouds will likely fill in across most of the coasts overnight
and may even push into some of the lower vlys.
Tomorrow looks like a more typical Srn CA kind of day. Look for
plenty of sunshine except for the morning low clouds at the csts.
Most areas will warm, but the csts may cool some as a stronger sea
breeze develops.
Forecast is in good shape and no updates are planned.
***From Previous Discussion***
Synoptically, the area is under an upper-level trough that
extends the length of California. Since yesterday, a closed 577
dam Low has formed within the trough and this feature will drive
our weather early next week. A ridge will begin to push in from
the southeast later today and through the weekend, moving the
closed Low further off the coast. By Monday afternoon, the Low
will be in a position to our southwest that will be favorable for
transporting more moisture back into the area and fueling another
round of rain and thunderstorms. Model solutions differ on the
speed with which this Low feature will move through the area to
our northeast so ensemble solutions are fairly widely spread on
details for Monday through Wednesday, but rain chances should
start Monday, peak on Tuesday, and decrease on Wednesday.
Areas under the marine layer should be a bit cooler on Saturday
than today, but outside of the marine layer, a slight warming
trend will begin.
A small amount of ensembles bring more tropical moisture into the
region as soon as Sunday so likely more cloudy than Saturday but
it looks like rain will wait until Monday.
Another surge of tropical moisture will most likely push into the
region Monday as the closed Low to our southwest transports the
moisture from what could be a developing tropical system.
Precipitable water value at KLAX climb back over an inch in all
of the forecast ensembles, potentially approaching or exceeding
1.50 inches. Increasing cloudiness with all the moisture in the
forecast.
.LONG TERM (TUE-FRI)...19/1255 PM.
Tuesday look to be the most active day to see showers and
thunderstorms. Rain totals for Tuesday are currently on the low
end, but any area under a strong shower could have much more rain.
Wednesday looks less likely, but rain cannot yet be ruled out.
Cloud cover is likely to increase across the region for early
portion of next week and could keep the temperatures on the cool
side of normal to near normal.
Thursday and Friday will bring gradual clearing and warming, with
downtown LA getting into the mid 80s. No impactful weather
expected those days.
&&
.AVIATION...20/0545Z.
At 0458Z at KLAX, the marine layer was around 600 feet deep. The
top of the inversion was 1300 feet with a temperature of 22 C.
High confidence in VFR TAFs for desert airfields (KWJF and KPMD).
Good confidence in VFR TAF for KPRB with only a 

NWS LOX Office Area Forecast Discussion