Atascadero, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

246
FXUS66 KLOX 200319
AFDLOX

Area Forecast Discussion
National Weather Service Los Angeles/Oxnard CA
819 PM PDT Fri Jun 19 2026

.SYNOPSIS...19/802 PM.

Below normal temperatures will continue through the weekend, with
a deep marine layer and a few spots of drizzle, as well as gusty
winds over the interior. A significant warming trend will start
Monday and peak around Wednesday. A push of moisture midweek will
bring at least a low chance for rain.

&&

.SHORT TERM (FRI-MON)...19/818 PM.

***UPDATE***

A cool but clear evening and night remains on tap. The low clouds
cleared in a similar fashion this afternoon as it did yesterday,
but is much slower in its redevelopment. Everything points to a
similar setup on Saturday as today, but this slow redevelopment is
both puzzling and a damper on any low cloud timing and coverage
confidence we might otherwise have. Otherwise, the forecast is on
track, with well below normal temperatures continuing through the
weekend, before temperatures start trending up on Monday. The
Extreme Heat Watch remains in effect for portions of Los Angeles
County for Tuesday through Thursday. The basis of this hazard is
certainly the warmer conditions, but also the potential impacts
with so many outdoor events scheduled and the fact that several
heat-related illness issues popped up during last weeks events
with cooler conditions that next week.

***From Previous Discussion***

June Gloom conditions will continue through this weekend, with
model guidance supporting a small weakening of onshore flow and
likely a gradual lowering of the marine layer depth as a result.
Morning low stratus should continue to push far inland, into many
of the valleys, through the weekend with at least moderate or
strong onshore flow.

Marine layer clouds this morning were similar to yesterday, with
cloud tops mostly in the 3000-3500 ft range. Cloud depth and
forcing was enough for scattered drizzle across many coastal
areas, with measurements up to 0.01-0.04". Hi-res ensembles, which
did fairly well identifying the drizzle this morning, support
potential for drizzle again Saturday morning favoring primarily
areas north of Point Conception and the coastal areas of LA
County. The hi-res keeps drizzle over the ocean for Sunday.

Temperatures this afternoon are forecast to be similar to
yesterday for most coastal areas and a few degrees cooler for
interior valleys, with 60s for the beaches and 70s for most
coastal areas away from the beaches. These highs are mostly 5-10
degrees below normal.

A shortwave trough will move through the area this afternoon,
imparting a brief enhancement to the southwesterly flow and
contributing to the below normal temperatures. With the enhanced
southwesterlies, a slight uptick in wind is expected, especially
across mountain tops and northeast-facing slopes. A Wind Advisory
is in effect this afternoon for western Antelope Valley, where
gusts up to 45 mph are possible. Winds will again be quite breezy
across the Antelope Valley Saturday afternoon, but not as strong
as today, and then winds will calm down further Sunday and Monday
as the onshore flow weakens and weak zonal flow develops aloft
following today`s shortwave.

There will be a small degree of warming this weekend, 1-3 degrees
each day, with the zonal flow and lowering marine layer, but
afternoon temperatures are forecast to remain below normal. Better
warming should then begin on Monday as heights rise over the area
with a building high to the southeast. Highs will be closer to
daily averages Monday.

.LONG TERM (TUE-FRI)...19/200 PM.

Warming temperatures will continue through the middle of next week
as high pressure continues to strengthen and spread further over
the area. Hgts will slowly rise over the area, with global models
still showing hgts peaking around 593-595 dam late-Tuesday or
Wednesday, which is about 8-9 dam higher than normal. Hgts of
this value will squish the marine layer down to 1000 ft or less
which will greatly reduce the amount of low clouds in the vlys. It
will, however, strengthen the marine inversion which will make
coastal clearing more difficult. Mdt to stg onshore flow will
continue although there will be weaker onshore flow to the north
in the morning. These onshore gradients and the strong capping
inversion will bring plenty of low clouds to the csts and some
lower vlys. The marine layer will moderate the cstl warming and
only 1 or 2 degrees of warming is likely each day there. For the
vlys and further inland areas, however, the absence of a marine
layer and building hgts will allow for 3 to 6 locally 8 degrees of
warming each day. By Tuesday triple digit heat is likely in the
Antelope Vly while the vlys will warm into the upper 80s and lower
90s.

The warmest days will likely be Wednesday and Thursday. Vly temps
will likely end up in the upper 80s to mid 90s. There is even a
low chance (5-10%) of eclipsing 100 in the San Fernando and Santa
Clarita valleys. These abnormally warm temperatures will lead to
pockets of moderate HeatRisk for some inland valleys. With the
potential for moderate HeatRisk in parts of the LA Basin, and the
consideration of the influx of visitors, an Extreme Heat Watch is
in effect for next Tue-Thu. This chc of heat warning will be
continuously monitored over the next three days.

In addition to the warming temps with the strong high pressure,
models point to a decent push of moisture up from Baja CA midweek,
with PWATs climbing up to 150% of normal. This moisture flux will
increase chances for rain showers and storms (5-10% chance). An
increase in mid and upper level clouds may also help alleviate
some of the heat impacts.

&&

.AVIATION...20/0015Z.

At 23Z at KLAX, the marine layer was 3000 ft deep. The top of the
inversion was near 4500 ft with a temperature of 19 Celsius.

High confidence in KPMD & KWJF staying VFR with gusty southwest
winds.

Moderate confidence in ceilings at all other airports. High
confidence in flight categories (MVFR-VFR), with a small chance of
brief IFR. Low confidence in timing (+/- 5 hours).

KLAX...High confidence in MVFR ceilings forming tonight. Low
confidence in timing (+/- 5 hours). No significant east wind
component expected.

KBUR...High confidence in MVFR ceilings forming tonight with
slightly stronger than usual onshore winds in the afternoon and
evening hours. There is a small chance of brief IFR.

&&

.MARINE...19/806 PM.

Fairly high confidence in winds and seas staying below Small
Craft Advisory (SCA) criteria through early next week, but
typically gusty winds of 15 to 20 knots will form each afternoon
and evening over portions of the nearshore waters as well as
around the Channel Islands. Very localized gusts to 25 may be
possible at times in those areas.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...Extreme Heat Watch in effect from Tuesday morning through
      Thursday evening for zones 88-368-372-373-379-380-548. (See LAXNPWLOX).
PZ...NONE.

&&

$$

PUBLIC...SB/RK
AVIATION...RK
MARINE...RK/BL/CC
SYNOPSIS...RK

weather.gov/losangeles

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