Chatsworth, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

945
FXUS66 KLOX 010237
AFDLOX

Area Forecast Discussion
National Weather Service Los Angeles/Oxnard CA
737 PM PDT Sat May 31 2025

.SYNOPSIS...31/133 PM.

Cooler but more humid conditions this weekend as tropical
moisture moves over the region, with a chance for showers or a
thunderstorm. Near normal conditions will follow Monday and
Tuesday, with a modest warm up towards the end of next week.

&&

.SHORT TERM (TDY-TUE)...31/213 PM.

Looks like the increased onshore flow is taking hold this
afternoon with temperatures in most areas starting to trend down
from yesterday. However, humidities are trending up as remnant
moisture from tropical storm Alvin moves into the area from the
southeast. No rain or thunderstorms yet as of 2pm in our area but
it`s been an active day across southern San Diego County.

That moisture is expected to work its way north through the rest
of the day and overnight. Forecast soundings in the mountains
show some impressive instability later this afternoon with CAPE`s
around 1500 J/kg in the northern Ventura and Santa Barbara County
mountains. Not quite as unstable in the LA Mountains but enough
for at least a slight chance of storms through the evening.
Steering flow aloft is from the east at around 10mph through this
evening then veers to the north later tonight into Sunday as the
upper lows moves inland. Could be some brief heavy rain with
storms and with the relatively light winds aloft there could be
some very isolated flooding.

At lower elevations south of Pt Conception there could also be
some scattered showers but rain falling through a deep dry layer
below 700mb means a lot that water will evaporate in transit. So
most populated areas will just see some sprinkles or light showers
at most.

This high PW air mass will continue into Sunday, but will start to
shift to the east, confining most of the activity east of Ventura
County. Instability parameters are not as favorable Sunday across
the area with the exception of the eastern San Gabriels where an
isolated storm is still possible through the early evening.
Otherwise, most areas will either be dry or just get some
sprinkles.

The muggy air tonight will likely keep overnight temperatures
warmer than usual so the Sunday lows have been increased above
most of the guidance numbers. Highs Sunday will continue the
cooling trend with most inland areas 5-10 degrees cooler than
today, and possibly more if clouds are thicker than expected.
Though the humidity will more than compensate for the decrease in
temperatures.

The area will be returning to more typical late Spring conditions
Monday and Tuesday as another upper low drops south along the
California coast and just offshore of Pt Conception Monday
afternoon. Increasing marine layer coverage is expected with
temperatures mostly 1-4 degrees below normal and either slow or no
clearing near the coast.

.LONG TERM (WED-SAT)...31/215 PM.

Little change expected Wednesday, with typical June Gloom
conditions on the coastal side of the ranges, and breezy warm
conditions on the desert side. Ensemble projections show a range
of outcomes for the back half of next week, ranging from little
change to a modest warm up as the flow turns more northwesterly.

&&

.AVIATION...01/0236Z.

At 0200Z, the marine layer was 900 feet deep at KLAX. The top of
the inversion was around 2400 feet with a temperature of 25 C.

High confidence in TAFs for KPRB, KPMD, and KWJF. Isolated
thunderstorms will continue this evening across the Santa
Barbara county mountains, with a 10% chance of reaching KSBA.
There is a 15% chance of IFR conds at KPRB 12Z-17Z. There is
a 15-25% chance of showers for areas south of Point Conception
through Sunday.

Moderate confidence in TAFs for KBUR and KVNY. There is a 30%
chance for LIFR to IFR conds 10Z-16Z.

Low confidence in remaining TAFs. Return of cigs tonight may be
off +/- 2 hours and minimum flight cat may be off by one cat, but
IFR to LIFR conds are most likely as marine layer depth remains
shallow. Slight deepening of the marine layer possible by Sun
morning.

KLAX...Low confidence in TAF. LIFR to IFR cigs expected tonight.
Slight deepening of marine layer expected by Sunday morning,
likely pushing cigs into MVFR category. No significant east wind
component expected.

KBUR...Moderate confidence in TAF. There is a 30% chance for IFR
to LIFR conds 10Z-16Z.

&&

.MARINE...31/732 PM.

For the Outer Waters conditions will remain below Small Craft
Advisory (SCA) levels through Sunday morning. There is a 40-50%
chance of SCA level wind gusts across the northern Outer Waters,
around Point Conception, and south to San Nicolas Island Sunday
afternoon into the overnight hours. Additionally, there is a 50%
chance for seas to reach 10 feet in the northern Outer Waters late
Sunday into Monday afternoon. Thereafter, conditions look to
remain below advisory criteria through next week.

For the nearshore waters along the Central Coast, high confidence
in conditions remaining below SCA criteria through the week.
However, there is a 20-30% chance for SCA level wind gusts Sunday
afternoon into late night.

For the Santa Barbara Channel, high confidence in conditions
remaining below SCA criteria through next week. However, there is
a 20% chance of SCA level wind gusts over the western portion
during the afternoon and evening hours on Sunday.

For the Inner Waters off the Los Angeles and Orange County coasts,
high confidence in conditions remaining below SCA levels through
next week.

An upper level low pressure system off the coast of Baja
California will bring a 10-20% chance of thunderstorms through
Sunday, especially south of Point Conception. Anything
thunderstorm could produce lightning, rain, and gusty, erratic
winds.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...Beach Hazards Statement in effect from Sunday morning through
      Tuesday afternoon for zones 354-362-366. (See LAXCFWLOX).
PZ...NONE.

&&

$$

PUBLIC...MW/Kittell
AVIATION...Gomberg
MARINE...Lewis/RAT
SYNOPSIS...RK

weather.gov/losangeles

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