Atascadero, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

942
FXUS66 KLOX 060446
AFDLOX

Area Forecast Discussion...UPDATED
National Weather Service Los Angeles/Oxnard CA
846 PM PST Fri Dec 5 2025

.SYNOPSIS...05/441 PM.

Light offshore winds will weaken through tonight. Benign weather
will continue through the weekend with a low chance of morning
coastal low clouds and fog. A significant warming trend will
begin Sunday with temperatures well above normal Monday through
next Friday, peaking Tuesday through Thursday. Offshore winds will
increase Sunday and Monday and continue into much of the week.

&&

.SHORT TERM (FRI-MON)...05/841 PM.

***UPDATE***

Marine layer clouds should start expanding further into the
coastal waters, potentially reaching some of the coasts this
weekend at times. However, generally lower confidence on this.
The LAX-DAG pressure gradient looks fairly weak through the
weekend, falling to near zero Saturday morning. With high pressure
aloft, there is potential for overnight to morning fog near many
of the coasts this weekend. Winds look stronger further north, and
Saturday night high resolution guidance suggests northeast to
easterly winds will ramp up over San Luis Obispo County and
portions of Santa Barbara County. Thinking these winds will be
sub-advisory levels, but the SMX-BFL pressure gradient is trending
more offshore into early next week. Current forecast looks on
track, but did make some minor edits to account for the fog bank
in the California Valley.

***From Previous Discussion***

This weekend will feature relatively quiet and inconsequential
weather with no hazards expected. Through Saturday, light
offshore winds in the morning will turn weekly onshore.
Temperatures will be widespread in the upper 60s to the mid 70s
across coastal and coastal valley areas through Saturday. Further
across the interior, max temperatures in the low 60s will
increase to the high 60s Saturday. There is a very low (10% or
less) chance for marine layer stratus to develop at coastal sites
in the late night to morning hours through Sunday. If any stratus
does develop, immediate coasts from Santa Barbara south to Los
Angeles County are most likely to be impacted, and dense fog is
likely. However, confidence is very low as stratus has yet to
develop anywhere across the nearshore waters.

The main focus in the short term will be the significant warming
trend beginning Sunday and intensifying Monday. A strong upper
level ridge will continue to build into the West Coast and the
mean LREF (ensemble of GEFS, EPS, and GEPS) shows 500 mb heights
building to 585-587 dam by Monday night. In addition to the upper
level pattern favoring significant warming, offshore flow from the
north and the east will begin to kick up Sunday and especially
Monday. The flow will help create additional downsloping
compressional heating for favored areas during the day, but at
night as well. Thus warmer overnight lows will be common. Max
temperatures on Sunday will be widespread in the 70s, with
warmest valleys reaching in the upper 70s and even approaching 80
degrees. A further uptick in max temps is on tap for Monday,
where highs will approach 8 to 15 degrees above normal. Monday
will feature warmest valley temperatures jumping into the low
80s. This will mark the beginning of a warm and dry week.

.LONG TERM (TUE-FRI)...05/152 PM.

The aforementioned ridge will park itself just off the West Coast
Tuesday and Wednesday before moving east where the apex of the
ridge will be over SoCal Thursday night into Friday. The mean LREF
500 mb heights vary between 585-589 dam during this time, which
is right around the 95th percentile of climatology. For reference,
the average December 500 mb height is 571 dam.

Again, offshore flow from the north and east will be mainstays
this week, peaking Tuesday-Thursday morning, but there have been
some fluctuations in magnitude of the LAX-DAG and LAX-BFL
gradients over the last couple days, especially regarding timing.
The most favored outcome in terms of wind speeds is somewhere in
the 15-25 mph range, with gusts between 25-35 mph and isolated 40
mph wind gusts across some of the favored mountain and foothill
areas.

It does appear that the offshore components will continue during
the daytime and overnight hours, which will help elevated max and
min temperatures further. Both max and min temperatures have been
nudged to the NBM 75th percentile, however, these still may be
slightly underdone, especially the min temperatures which will be
impacted very much so by the overnight offshore flow. All four
counties are in play for the offshore flow during the entire week.

Tuesday-Thursday are looking like the warmest days of this warm
spell, although Friday is now looking quite warmer than it
appeared yesterday, and there will be very little fluctuations in
high temps during this period. There is some discrepancy between
the EC and GFS operational runs, as the GFS begins to cool the
region Thursday and Friday. However, most ensemble members favor
the EC at this point, hence why temperatures were nudged up. High
temperatures will be 10-20 degrees above normal during this
period, with isolated warmest mountain areas approaching 25
degrees above normal.

&&

.AVIATION...06/0040Z.

At 2353Z at KLAX, there was no marine layer. A surface based
inversion top was at 1200 feet with a temperature of 17 degrees
Celsius.

There is a 30% chance of LIFR FG at KPRB between 10Z-16Z Sat. The
chance of lowered categories elsewhere is 10% or less.

KLAX...High confidence in the 00Z TAF with VFR conditions through
at least Saturday, except for a 10% chance of LIFR FG Saturday
12Z-16Z. East winds are likely between 08Z to 18Z, but the chance
of exceeding 8 knots is less than 10%.

KBUR...High confidence in the 00Z TAF with VFR conditions through
at least Saturday.

&&

.MARINE...05/842 PM.

Moderate confidence in low-end Small Craft Advisory (SCA) NW winds
for the Central Coast waters beyond 20 miles from shore and
southward to the Channel Islands tonight through much of the
forecast period. NE winds near 20 knots likely each night and
early morning into next week nearshore from Port San Luis and
northward. Otherwise, moderate confidence in unusually light winds
and small seas across the remainder of the waters through at
least this weekend. N-NE winds likely to increase Monday and
Tuesday of next week from Ventura through Santa Monica, with a 40%
chance of reaching SCA.

There is a chance of dense fog forming over the coastal waters
tonight or sometime this weekend, with the highest chances south
of Point Conception. Confidence is low on timing and coverage.

Abnormally high tides will lower each day through next week.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...Beach Hazards Statement in effect through Saturday morning
      for zones 87-349-350-354-362-366. (See LAXCFWLOX).
PZ...Small Craft Advisory in effect until 3 AM PST Sunday for
      zones 670-673. (See LAXMWWLOX).

&&

$$

PUBLIC...Phillips/Lewis
AVIATION...Ciliberti
MARINE...Kittell/CC
SYNOPSIS...Lewis/CMC

weather.gov/losangeles

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