Arroyo Grande, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

513
FXUS66 KLOX 112257
AFDLOX

Area Forecast Discussion...UPDATED
National Weather Service Los Angeles/Oxnard CA
357 PM PDT Sat Apr 11 2026

.SYNOPSIS...11/355 PM.

Moderate rain and a chance of thunderstorms will sweep through
the area tonight into Sunday morning. Scattered shower activity
is then possible Sunday afternoon into Monday morning. Dry and
warmer weather is expected the rest of next week.

&&

.SHORT TERM (TDY-TUE)...11/206 PM.

Overall, 12Z models in good synoptic agreement through the period.
At upper levels, low will move across Northern California tonight
and Sunday which will sweep a potent cold front across the region
tonight/Sunday. On Monday, an upper level trough will move across
the area with an upper level ridge building offshore on Tuesday.

Forecast-wise, main focus continues to be on potent cold front,
sweeping across the area tonight/Sunday. Some light warm frontal
rain can be expected through this evening across the area.
Overnight, the cold front will sweep across the area, finally
exiting Los Angele county Sunday afternoon. There may be some
lingering showers Sunday night, but dry conditions are expected
for Monday and Tuesday.

Rainfall totals through Sunday night are expected to range between
0.50 and 1.50 inches with local amounts around 2.00 inches in the
foothills/mountains. Rainfall rates are expected to be in the 0.25
to 0.50 inch/hour range, but locally higher rates around 0.75
inches/hour will be possible with thunderstorm activity. So, minor
nuisance flooding is likely, but major flooding/debris flows
remain unlikely. This frontal passage will be rather dynamic
(decent CAPE, etc), resulting in a 15-25% chance of thunderstorms.
Any thunderstorms that develop will likely produce brief heavy
rain, gusty outflow winds, small hail and potentially waterspouts
or weak, short-lived, tornadoes.

As for winter weather issues, snow levels are currently running in
the 6000-8000 foot range, but will drop to the 4500-6000 foot
range tonight/Sunday. So, there will be several inches of snow
accumulation (5-10 inches) expected above 6000 feet. Given the
expected snow totals, and some gusty southwesterly winds, the
WINTER WEATHER ADVISORIES will remain in effect for the mountains
of Santa Barbara/Ventura/LA counties.

A secondary weather concern will be winds. As the front passes
through tonight/Sunday, southwesterly winds, gusting 30-45 MPH,
will be likely across the mountains/interior sections. At this
time, expect any advisory-level gusts to remain localized. So,
no advisories will be issued with the afternoon forecast.
However, future shifts will need to watch that potential closely.

Finally as for temperatures, cool conditions can be expected
Sunday and Monday with highs generally 5-10 degrees below normal.
On Tuesday, highs will begin to rebound, but still will top out a
degree or two below normal.

.LONG TERM (WED-SAT)...11/207 PM.

For the extended, 12Z models continue to be on the same, broad,
synoptic page. Weak upper level trough will persist over the area
on Wednesday, then an inside slider will drop into the Great Basin
Thursday/Friday.

Forecast-wise, the extended will be expected to remain rather
benign. Mostly clear/partly cloudy and dry conditions are
expected through the period. There could be some return of coastal
stratus/fog later in the extended period, but not confident
enough to include in the official forecast. On Thursday/Friday,
there will likely be an increase in northerly across the area as
the inside slider dives into the Great Basin. At this time,
ensembles are indicating a 50-70% chance of advisory-level
northerly winds in the usual spots (I-5 Corridor and the Santa
Barbara county mountains). As for temperatures, will expect a
warming trend through the period with temperatures peaking on
Saturday (about 4-8 degrees above normal).

&&

.AVIATION...11/1815Z.

At 1715Z at KLAX, there was no marine inversion present.

Moderate confidence in the 18Z TAFs. For coast and vly airfields,
SCT-BKN conds with layers around 025-050 will likely continue
through this afternoon, then generally BKN-OVC025-040 tonight into
Sun morning except some airfields could see BKN015 at times. The
desert airfields will be VFR until late tonight into Sun morning
when BKN-OVC025 and lowered vsbys with rain is expected to move
in. Overall, moderate confidence in the cig fcst and timing
between cig cats.

A cold front will affect all terminals tonight into Sun morning.
There is good confidence in rain timing. Low confidence in cig/vis
fcst when the rain is occuring. This weather system will also
bring a chance of thunderstorms, especially for northern
airfields, later tonight into Sun morning. Any thunderstorms
could produce gusty and erratic winds and brief lower vsbys in
heavy rain.

KLAX...Moderate confidence in TAF. SCT-BKN conds with layers
around 035 to 050 are likely through 03Z. Lower confidence after
03Z with lower cigs possible. Good confidence in -RA after 11Z.
The rain will bring variable cig/vis along with south winds.
There will be a 25 percent chc of a TSTM 11Z-16Z. No significant
east wind component expected.

KBUR...Moderate confidence in TAF. SCT-BKN conds with layers
around 035 and 050 are likely through 11Z. Lower confidence after
11Z with lower cigs possible. Good confidence in -RA after 08Z.
The rain will bring variable cig/vis. There will be a 25 percent
chc of a TSTM 11Z-16Z.

&&

.MARINE...11/120 PM.

A rather potent weather system will affect the southwestern CA
coastal waters tonight into Sunday. This system will sweep a cold
front across the waters, bringing Small Craft level southerly
winds, showers and a chance for thunderstorms to the area.
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 9-10 feet across the central and
northern Outer 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 for much of the time
across the outer waters Tuesday through Thursday night, with a 20%
chance of Gale Force winds at times Thu night.

&&

.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 until 3 AM PDT Sunday for
      zones 645-670-673. (See LAXMWWLOX).

&&

$$

PUBLIC...Thompson
AVIATION...Sirard
MARINE...Sirard
SYNOPSIS...MW/CC

weather.gov/losangeles

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