Moorpark, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

107
FXUS66 KLOX 131127
AFDLOX

Area Forecast Discussion
National Weather Service Los Angeles/Oxnard CA
427 AM PDT Sun Apr 13 2025

.SYNOPSIS...13/319 AM.

More marine influence and stronger onshore flow will continue a
gradual cooling trend. Night through morning low clouds and fog
with patchy drizzle at times will be a staple of the forecast. Low
clouds will push into the coastal slopes of the mountains by
Tuesday. A cold upper level low pressure system will bring
additional cooling and a chance of showers to the area between
late Thursday and early Saturday. An afternoon or evening
thunderstorm cannot be ruled out during that time.

&&

.SHORT TERM (TDY-TUE)...13/352 AM.

An upper-level trough of low pressure continues to move over the
state this morning. Low clouds and fog remain entrenched across
most coastal and valley areas early this morning. Clouds are less
developed into the Santa Barbara Channel and the Santa Barbara
South Coast and western Ventura County. Clouds will start to
spread into these areas as an eddy circulation regenerates. Patchy
drizzle cannot be ruled out this morning as a weak vorticity
maximum moves over the area this morning. The marine layer depth,
near 1300 feet deep several hours ago at KLAX, should be
approaching 1800 feet deep south of Point Conception, sloping
lower to near 1200 feet deep for areas north of Point Conception.
As the marine layer deepen closer to 2000 feet deep, the depth of
the clouds could start to interact with the dynamics aloft. The
marine layer stratus deck could lift and start to squeeze some
precipitation in the form of drizzle. With the marine layer depth
deepening quite rapidly, an early morning push of low clouds and
fog into the Santa Clarita Valley cannot be ruled out.

A general cooling trend should continue into Tuesday as a stronger
onshore flow and more cooler marine air will move in. A brief
break in the cooling trend could develop on Monday as a shortwave
along the North Coast of California digs, cuts off from the flow
pattern, and retrogrades from the California coastline. This will
weaken the onshore push slightly and bring a few degrees of
warming on Monday.

By Tuesday, broader cyclonic flow will move back into the region
as another trough sitting near 30N and 127W will phase with the
new cutoff low off the Central Coast of California and lift out
into southern California. This will bring substantially deepening
to the marine layer depth and the possibility of night through
morning drizzle. The low cloud field will expand into the coastal
slopes of the mountains between Monday night and Tuesday as the
marine layer depth deepen to near 2500 feet deep. With onshore
pressure gradients approaching 8 mb between KLAX and KDAG, clouds
will likely to struggle to clear from the beaches on Tuesday and
may struggle to clear from the coast and valley areas across the
Southland. Future shifts will need to take a closer look at this
as the scattering out of the low clouds may be inhibited greatly
by the strong onshore gradients.

.LONG TERM (WED-SAT)...13/426 AM.

A colder upper-level trough near 40N and 155W will drop into the
region between Tuesday and Wednesday and combine with the cutoff
trough off the Central Coast. The resultant trough will deepen to
near 560 dam, as it approaches the California coast. Increasing
onshore flow and a deeper marine layer will bring cooler
conditions with the threat of night through morning drizzle
occurring. A few mountain showers cannot be ruled out for
Wednesday afternoon and evening as the trough passes over the
region.

Shower chances will increase for late week as a cold trough near
the Aleutian Islands this morning will move over the top of the
ridge near British Columbia and dig down into the region. This
trough will much be colder, piping colder air in from Canada, as
it takes an inside track. The trough will bottom out near Point
Conception and is likely to pick up some Pacific moisture in the
process to work with for precipitation. EPS precipitable water
value means increase to around 0.75 inch on Thursday and a
majority of the ensemble members have precipitation for sometime
between late Thursday and early Saturday. There is a non-zero
chance for thunderstorms, especially during the afternoon and
evening hours as the colder air mass could turn unstable with
daytime heating. While there is much uncertainty with this trough,
there is a lesser chance that a drier forecast could result with
continued night through morning low clouds and fog with drizzle.

A warming trend should develop for next weekend with weakening
onshore flow and less low clouds and fog. Cluster analysis favors
stronger troughing pushing to the east and allowing for a ridge
over the Pacific Ocean to nose in.

&&

.AVIATION...13/0131Z.

At 2316Z at KLAX, the marine layer was around 1200 feet deep. The
top of the inversion was around 2400 ft with a temp of 19 C.

Overall, moderate to low confidence in 00Z TAF Package. Best
confidence in desert airfields (KPMD, KWJF) with VFR conds
expected thru fcst pd. There is a 30% chance of IFR cigs at
KOXR & KCMA from 10Z to 18Z Sun. There is a 10% chance of LIFR
cigs at KSMO from 08Z to 18Z. There is a 30% chance of IFR cigs
or lower at KLGB from 06Z to 16Z and similar chances at KVNY from
10Z to 16Z.

Timing of cig/vsby restrictions may be off +/- 2 hours. Flight
cats could be off one or two, especially during minimums.

KLAX...Moderate confidence in 00Z TAF. Expect MVFR to IFR cigs
through 17Z-18Z with a low chance (20%) at LIFR conds
(