Acton Weather

345
FXUS66 KLOX 111005
AFDLOX

Area Forecast Discussion
National Weather Service Los Angeles/Oxnard CA
305 AM PDT Sat Apr 11 2026

.SYNOPSIS...11/304 AM.

It will be mostly dry Saturday with cooler than normal
temperatures. Moderate rain and a chance of thunderstorms will
likely sweep through the area Saturday night into Sunday morning.
Scattered shower activity is possible Sunday afternoon into Monday
morning. Dry and warmer weather is expected the rest of next
week.

&&

.SHORT TERM (TDY-MON)...11/304 AM.

The first front moved through the area with little affect. Leaving
only a mishmash of low clouds in its wake. The latest hi rez mdls
indicate that this morning and afternoon should be dry save for a
slight chc of afternoon showers across the Central Coast and even
then mostly just SLO county. Skies today will be partly cloudy.
Max temps will cool 1 to 3 degrees due to the cool air funneling
in behind ydy`s front. Max temps across the csts/vlys will mostly
be in the mid to upper 60s.

All eyes still on tonight when the much more cohesive and
vigorous front will pass through the area. The latest RRFS run
shows little change to the previous thinking. With rain starting
in SLO county in the evening and then reaching LA county after
midnight. The good dynamics and increasing instability will bring
a 3-5 hour period of steady rain and possible thunderstorms to
the entire forecast area. CAPE values of around 500j/kg will
provide the necessary lift for convective activity, including
brief heavy downpours, gusty winds, and possible lightning. There
is enough helicity in the lower layers to spin up a small tornado
or waterspout in any TSTM that forms.

Rain amounts expected to generally be a half to one inch, except
locally higher in the mountains and along the Central Coast. Due
to the convective nature of this storm, rain amounts could vary
quite a bit, even over very short distances. Rain rates expected
to top out around a quarter to half inch per hour, except very
brief and isolated rates as high as 0.75" in the strongest storms.

Strong southerly winds will develop ahead of the front and 35 to
45 mph gusts are likely across the mtns.

A Winter Weather Advisory is in effect starting at 900 pm for the
higher mountains, above 5000 feet. Snow levels will be around
7000 feet through Sunday morning, then lowering to around 5000
feet Sunday afternoon into Monday morning. Snow accumulations of
up to 6 inches are possible above 7000 feet, and 1-3 inches as low
as 5000 feet. Not expecting any snow accumulations on the
Grapevine over I-5, though there could be a mix of rain and snow
early Monday morning.

Rain will taper off pretty quickly behind the front and by
afternoon there will only be a 20 to 30 percent chc of showers
across the area with the greatest chc over eastern LA county and
there will only a the mtns.

2 to 4 locally 6 degrees of cooling due to all of the cold air
advection behind the front will bring max temps down to a January
like lower to mid 60s.

Earlier mdl runs were showing another impulse moving through
Monday with additional rain chcs. This is no longer shown and
Monday should be partly cloudy and dry with a 2 to 4 degree
warming trend. Max temps will still end up 4 to 8 degrees blo
normals.

.LONG TERM (TUE-FRI)...11/256 AM.

Dry and warmer conditions will persist through the rest of the
week. There will be weak ridging on Tuesday followed by dry NW
flow on Wednesday. A dry trof moves through the state on Thursday.
There is a bit of disagreement on the Friday upper level pattern
with a troffier EC solution and a flatter GFS fcst. At the sfc
there will be weak offshore flow from the N and weak to moderate
onshore flow to the east. Can`t rule out some night through
morning low clouds esp Thu and Fri.

After the chilly start to the week there will be 3 to 6 degrees of
warming on Tue, followed by and additional 1 to 3 degrees on Wed.
Looking for little change in temps on Thu. The current forecast
calls for more warming on Friday, but this really depends on what
mdl solution verifies best.

&&

.AVIATION...11/1003Z.

At 0822Z at KLAX, the marine layer was 1500 ft deep. The top of
the inversion was at 2200 ft with a temperature of 15 C.

Good confidence in TAFs for KPMD and KWJF.

Moderate confidence in the remainder of the TAFs. SCT-BKN conds
with layers around 015, 025 and 035 will likely continue through
the morning. Better confidence in mostly VFR conds in the
afternoon KSBA and points south.

A cold front will affect all terminals this evening and overnight.
There is good confidence in rain timing. Low confidence in cig/vis
fcst when the rain is occuring.

KLAX...Moderate confidence in TAF. SCT-BKN conds with layers
around 015, 025 and 035 are likely through 18Z. Good confidence
in CIGS AOA 100 18Z-02Z. Lower confidence after 02Z with lower
cigs possible. Good confidence in -RA after 09Z. The rain will
bring variable cig/vis along with east winds. There will be a 25
percent chc of a TSTM 11Z-16Z. No significant east wind component
expected through 08Z then increasing chances of at least a 10 kt
east wind component.

KBUR...Moderate confidence in TAF. SCT-BKN conds with layers
around 015, 025 and 035 are likely through 18Z. Good confidence
in CIGS AOA 100 18Z-02Z. Lower confidence after 07Z with lower
cigs possible. Good confidence in -RA after 09Z. The rain will
bring variable cig/vis. There will be a 25 percent chc of a TSTM
11Z-16Z.

&&

.MARINE...11/304 AM.

A weak cold front will move across the coastal waters through
this morning bringing showers and a slight chance for a
thunderstorm north of Point Conception.

A second system will arrive late this afternoon into Sunday. This
front will be stronger, bring Small Craft level southerly winds,
showers and a chance for thunderstorms across all waters.
Potential hazards include: heavy downpours, dangerous cloud to
ocean lightning, small hail, and erratic gusty winds. Boaters,
especially those with small vessels should avoid these conditions.

Seas will build on Sunday to near 10 feet across the Outer Waters
and to 5-7 feet across the Inner Waters. Additionally Small Craft
level west to northwest winds are likely for all the waters
Monday afternoon and night. Then northwest SCA winds are possible
each afternoon and evening Tuesday through Friday across the outer
waters.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...Winter Weather Advisory remains in effect from 9 PM this
      evening to 11 AM PDT Monday for zones 353-376-377. (See LAXWSWLOX).
     Winter Weather Advisory remains in effect from 3 AM Sunday to
      11 AM PDT Monday for zones 378>380. (See LAXWSWLOX).
PZ...Small Craft Advisory in effect from noon today to 3 AM PDT
      Sunday for zones 645-670-673. (See LAXMWWLOX).

&&

$$

PUBLIC...Rorke
AVIATION...Rorke
MARINE...RS/RM
SYNOPSIS...MW/CC

weather.gov/losangeles

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