Monrovia, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

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FXUS66 KLOX 240504
AFDLOX

Area Forecast Discussion
National Weather Service Los Angeles/Oxnard CA
1004 PM PDT Mon Jun 23 2025

.SYNOPSIS...23/819 PM.

Expect cooler temperatures through Tuesday, then warmer again
Wednesday through Friday as high pressure returns. Night through
morning low clouds and fog are expected for many coastal areas
this week, but decreasing across the valleys. Otherwise clear
skies with mostly light winds are expected.

&&

.SHORT TERM (MON-THU)...23/959 PM.

***UPDATE***

Marine layer clouds returned to most of the coasts last night,
leading to cooler highs, especially along the Central Coast where
temperatures struggled to reach the 60s. Further inland, highs
reached the 70s and 80s. Temperatures Tuesday and through the week
will trend warmer as the upper level low slides off to the east,
especially for the interior. Marine layer clouds will limit
warming at the coasts, and should affect most of the coastal areas
and some valleys on Tuesday. As high pressure continues to build,
marine layer clouds and fog will be more limited to the coasts.
Current forecast looks on track, but warmed a few areas over the
interior 2-4 degrees given today`s high temperatures.

***From Previous Discussion***

Synoptically, there is an upper level trough extending southwards
across California while a very strong (595 dam) upper High is over
the Eastern US. 578 dam heights overhead will grow to about 588
dam by Wednesday as the trough fills. By Friday the pattern
becomes zonal and the lower two thirds of the US will be under a
broad area of higher heights.

Expecting night to morning low clouds and stratus overnight, with
a similar inland extent on Tuesday morning. Expect very little
change from today`s weather.

As the trough weakens and moves east on Wednesday temperatures
will warm several degrees, with afternoon highs back to near or
slightly above seasonal normal.

The trough will continue to weaken on Thursday and temperatures
will warm another degree or so. Downtown LA will be in the low
80s, Paso Robles in the mid 90s, and the Antelope Valley could
reach 100.

.LONG TERM (FRI-MON)...23/137 PM.

Minimal day-to-day temperatures changes are expected in the
extended period, with highs in the 80s to lower 90s in the
valleys and mostly 70s closer to the coast. High pressure aloft
should confine the marine layer to coastal areas and possibly
portions of the San Gabriel and Santa Ynez Valleys.

Temperatures are expected to peak on Saturday and then slight
cooling is projected through Tuesday as weak trough may return to
the West Coast.

&&

.AVIATION...24/0233Z.

At 2339Z at KLAX, the marine layer was 1300 ft deep. The top of
the inversion was at 3200 ft with a temperature of 16 C.

Overall, moderate confidence in 00Z TAF Package. VFR conds
expected at desert airfields (KPMD & KWJF), and KPRB.

For remaining sites, timing of CIG/VSBY restrictions may be off
+/- 2 hours with flight minimums off by 1 category.

KLAX...Moderate confidence in 00Z TAF. Arrival and Departure
times of MVFR CIGs 010-020 may be off +/- 2 hours. No significant
east wind component expected.

KBUR...Moderate confidence in 00Z TAF. Arrival times of cigs may
be off by 1-2 hours.

&&

.MARINE...23/819 PM.

For the Outer Waters, Small Craft Advisory (SCA) winds are
affecting the waters between Point Conception and Santa Cruz
Island, with a 30-40 percent chance they spread southward toward
San Nicolas Island. A SCA has been issued for PZZ673 through late
tonight. There are moderate chances (30-50%) for low- end SCA
winds during the afternoon and evening hours Tuesday through
Thursday, especially around Point Conception. Seas are expected to
fall well below SCA criteria Monday and will likely remain sub
SCA through at least Friday.

For the Inner Waters, there a is a 20-30 chance for low-end SCA
winds focused Tuesday through Thursday late afternoons/evenings
along the Central Coast and western portions of the Santa Barbara
Channel.

Patchy dense fog is possible off of the Central Coast during the
evening to morning hours through at least Tuesday morning.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
PZ...Small Craft Advisory in effect until 3 AM PDT Tuesday for
      zone 673. (See LAXMWWLOX).

&&

$$

PUBLIC...Phillips/jld
AVIATION...Phillips
MARINE...Munroe/Black/Ciliberti
SYNOPSIS...jld/Ciliberti

weather.gov/losangeles

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