Casa Conejo, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

177
FXUS66 KLOX 181610
AFDLOX

Area Forecast Discussion...UPDATED
National Weather Service Los Angeles/Oxnard CA
910 AM PDT Sun May 18 2025

.SYNOPSIS...18/908 AM.

Slightly warmer temperatures are on tap for today, then very hot
weather and clear skies is expected starting Monday through the
workweek. High temperatures will be well above normal for this
time of year each week day. Gusty southwest winds are expected
through tonight in the Antelope Valley, while gusty north winds
are expected across southwest Santa Barbara County and in the Los
Angeles County Mountains near the Grapevine.

&&

.SHORT TERM (TDY-TUE)...18/858 AM.

***UPDATE***

Marine layer clouds are in the process of burning off this
morning, however lingering deep moisture may cook up into a
stratocumulus deck this afternoon (especially over the LA
coasts/valleys). The weakening onshore flow combined with rising
500 mb heights and much more sunshine (compared to the last
several days) will allow for 3 to 6 degrees of warming at the
coasts and 6 to 12 degrees over the rest of the area. High
temperatures will largely be in the 70s today, with some of the
warmer valleys squeaking into the 80s, and the coasts in the 60s
to low 70s. This warming will not be enough, however, to bring max
temps up to normals.

The NW flow and moderate onshore flow to the east have brought
advisory level gusts to the Antelope Valley and its western
foothills as well as the I-5 Corridor. Later this afternoon,
advisory level winds will develop again across much of the SBA
south coast.

No updates were needed to the morning forecast. Will be looking at
potentially adding some wind advisories for the Santa Barbara
mountains and south coast, and possibly the Ventura County
Mountains for later this afternoon and evening. Additionally, will
be assessing the need for headlines for the multi-day heat event
this week.

***From Previous Discussion***

The marine layer is about 4500 ft deep and contains two
inversions. This has generated two separate cloud layers. In
addition offshore trends and increasing NW flow aloft have
disrupted the low cloud formation in many places. The NW flow has
also created upslope clouds across the nrn mtns next to the Kern
County line.

Continued offshore trends will lead to actual offshore flow Monday
morning, esp from the north. Marine layer stratus will likely be
confined to the LA county beaches and there is a 30 percent chc
that even these areas will be cloud free. Ridging will move over
the state and hgts will rise to 582 dam. Max temps will jump 3 to
6 degrees across the coasts and 6 to 12 locally 15 degrees over
the rest of the area. Most max temps will end up 4 to 8 degrees
above normal.

The ridge flattens out on Tuesday but hgts rise a couple of dam up
to 584 dam. The offshore flow continues and skies will be cloud
free. Most of SLO and SBA counties will only warm 1 or 2 degrees.
VTA and LA counties, however, will see another 4 to 8 degrees of
warming as the offshore flow will have the greatest affect in this
location. Look for 4 to 8 degrees of additional warming. MAx temps
across the csts will be in the 70s except the interior portions
of the LA/VTA csts where lower to mid 80s will be common. The vlys
will all see max temps in the 90s. These temps will be close to
advisory criteria but just under. Still people working or playing
outside in the vlys should be aware of heat dangers.

.LONG TERM (WED-SAT)...18/332 AM.

Hgts and temps peak on Wednesday and it looks like the vlys will
see max temps from 95 to 103 degrees (15 to 20 degrees above
normal). In addition there will be a very strong inversion around
1000 ft (right at many vly elevations) and this will also keep
many overnight lows will above normal. Slightly lower hgts and
slightly stronger onshore flow will bring some cooling Thursday
but not really enough to reduce the heat danger. Heat advisories
look very likely for both days and people should take notice and
perhaps adjust any outdoor plans. There will still be some onshore
flow to the east and this will make the beach temperature
forecast tricky as there could be a huge temp gradient between the
beaches and the inland areas.

The ridge weakens and onshore flow increases both on Fri and Sat.
A shallow marine layer cloud deck could develop across some of the
coasts. Max temps will fall 3 to 6 degrees Fri and then 5 to 10
degrees on Sat. By Sat most max temps will only be 3 or so degrees
over normal.

&&

.AVIATION...18/1052Z.

Around 07Z, the marine layer depth was near 2200 feet deep at KLAX.
The top of the marine inversion was near 2500 feet with a
temperature near 12 degrees Celsius. There was another inversion
above up to around 4700 feet.

Low to moderate confidence in the current forecast for all
terminals, except high confidence in the current forecast for
desert terminals. Conditions could vary between MVFR and VFR
through this morning. There is a moderate chance of IFR
conditions through 14Z. Otherwise, MVFR conditions will likely
persist through at least 15Z at Central Coast terminals and Los
Angeles County coastal and valleys terminals, then VFR conditions
should develop through 19Z. There is a moderate to high chance of
LIFR to IFR conditions after 08Z Monday for Central Coast
terminals and Los Angeles County coastal terminals.

KLAX...MVFR conditions will likely persist through at
least 16Z, then VFR conditions could develop as soon as 16Z, or as
late as 19Z. There is a 50 percent chance of IFR conditions after
08Z Monday. Any east winds should remain less than 7 knots.

KBUR...MVFR conditions will likely persist through at
least 15Z, then VFR conditions could develop as soon as 15Z, or
as late as 17Z.

&&

.MARINE...18/909 AM.

Relatively low confidence in the current forecast. Higher
confidence in the current forecast for seas compared to winds.

For the Outer Waters and the nearshore waters along the Central
Coast, there is a 80-100 percent of Small Craft Advisory (SCA)
conditions through Tuesday night, except for lulls nearshore along
the Central Coast in the overnight/early morning hours. While
local GALE force wind gusts may occur this morning, chances for
more widespread GALES increase to 50-80 percent chance this
afternoon into the late night hours. The highest chances will be
for the majority of the Outer Waters, while the lowest chances
will be for the nearshore waters along the Central Coast. The
chances for GALES will reduce early Monday morning to a 40-60
percent chance, but the chances will increase again to a 50-80
percent chance by Monday afternoon into the late night hours,
with highest chances for the northern Outer Waters. Then, there is
a 30-40 percent chance for GALES again Tuesday afternoon through
late night.

Inside the southern California bight, there is a 60 percent
chance of SCA level winds this afternoon through late tonight,
focused across the western portion of the Santa Barbara Channel.
Local GALE force wind gusts may occur in the very extreme western
portion of the Channel. Winds are expected to remain below SCA
levels in the southern Inner Waters except for local gusts to
20-25 kts in typical windy spots, including the San Pedro Channel.
Slightly higher chances exist for SCA level winds Monday
afternoon into the evening hours, but strongest winds will most
likely remain away from the immediate coast. Lower chances exist
Tuesday.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...Wind Advisory remains in effect until 10 AM PDT Monday for
      zone 378. (See LAXNPWLOX).
     Wind Advisory remains in effect until 3 AM PDT Monday for
      zones 381-383. (See LAXNPWLOX).
PZ...Small Craft Advisory in effect until 3 PM PDT this afternoon
      for zones 645-670-673-676. (See LAXMWWLOX).
     Gale Warning in effect from 3 PM this afternoon to 9 PM PDT
      this evening for zone 645. (See LAXMWWLOX).
     Gale Watch in effect from Monday afternoon through Monday
      evening for zone 645. (See LAXMWWLOX).
     Small Craft Advisory in effect from 3 PM this afternoon to 3
      AM PDT Monday for zone 650. (See LAXMWWLOX).
     Gale Warning in effect from 3 PM this afternoon to 3 AM PDT
      Tuesday for zone 670. (See LAXMWWLOX).
     Gale Warning in effect from 3 PM this afternoon to 3 AM PDT
      Monday for zones 673-676. (See LAXMWWLOX).
     Gale Watch in effect from late tonight through late Monday
      night for zones 673-676. (See LAXMWWLOX).

&&

$$

PUBLIC...Rorke/Lund
AVIATION...Hall
MARINE...Hall/Lewis
SYNOPSIS...KL

weather.gov/losangeles

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