709
FXUS66 KLOX 220040
AFDLOX

Area Forecast Discussion...UPDATED
National Weather Service Los Angeles/Oxnard CA
540 PM PDT Fri Mar 21 2025

.SYNOPSIS...21/150 PM.

Dry and occasionally breezy conditions through next week.
Temperatures will be near or slightly above normal today and
Saturday. A significant warmup is expected Sunday into Monday.
High temperatures Monday will be well above normal, well over 90
degrees most likely in the coastal valleys of Los Angeles and
Ventura Counties. A cooling trend will commence after Tuesday with
temperatures closer to normal for the remainder of next week.

&&

.SHORT TERM (TDY-MON)...21/157 PM.

Clear conditions continue across Southern California this
afternoon with temperatures slightly above normal across the
region.

A weak upper level trough will bring an increase in onshore
pressure gradients late tonight through Saturday with possible low
clouds due to a strengthening marine layer near the coast of Los
Angeles, especially towards the border with Orange County, but
other areas the coverage should be minimal. Saturday afternoon
seabreezes will also be quite gusty especially through the passes
and canyons. Temperatures will be a couple of degrees cooler on
Saturday near the coast and valleys but otherwise not much change
there either.

An upper level ridge will begin to strengthen on Sunday bringing a
pronounced warming period to the region that will stretch through
early next week, with significantly above normal temperatures.

.LONG TERM (TUE-FRI)...21/202 PM.

An upper level ridge will be strong early next week over Southern
California, peaking likely Monday with a 584 DM ridge over SE CA
and SW AZ. Light north to northeast winds away from the coast,
combined with a shallow marine layer, will support highs Monday
around 20 degrees above normal in most areas. Temperatures
will rise into the lower to mid 90s over the coastal valleys in
Los Angeles and Ventura Counties. Heat advisories may be needed
for local areas in Los Angeles by Monday.

Heights will fall by Wednesday as an upper low approaches the
region, with falling heights and increasing onshore flow.

Additional cooling is possibly on Thursday as a larger trough
moves into the eastern Pacific, but there is a chance that cooling
from that system will not occur until Fri. In any event, max
temps will likely still be several degrees above normal in most
areas Wed and Thu, though night thru morning low clouds may return
to coastal areas.

Longer term ensemble guidance shows the potential for rain by the
first few days of April, stay tuned as we continue to examine the
latest forecast data!

&&

.AVIATION...21/2311Z.

At 2231Z at KLAX, the marine layer depth was around 700 feet. The
top of the inversion was 1500 feet with a temperature of 18 C.

Overall, high confidence in 00Z TAF Package. There is a 10% chc of
LIFR conds at KPRB from 10Z to 18Z Sat. There is a 10-20% chc of
MVFR/IFR conds at KOXR, KCMA, KLGB from 08Z to 18Z Sat. Otherwise,
expect VFR conds thru fcst pd.

KLAX...High confidence in 00Z TAF. VFR conds in general are
expected, but there is a slight chance (10-20%) of MVFR cigs
(010-015) and a non-zero chc of high-end IFR conds from 08Z to
16Z. No significant east wind component is expected.

KBUR...High confidence in 00Z TAF.

&&

.MARINE...21/536 PM.

For the Outer Waters, high confidence in a combination of Small
Craft Advisory (SCA) level northwest winds and seas continuing
through Sunday. Localized Gale force NW gusts are possible to
likely from this afternoon thru the late night hours tonight in
PZZ676/673.

Potential for GALE force wind gusts are expected to become more
widespread tomorrow - expanding into PZZ670. Comparing yesterday`s
buoy observations to model guidance, the HREF was a close match.
The HREF probabilities for GALES has trended upwards the last
few cycles increasing confidence. The spatial coverage of GALES
appears to be adequate along with other factors, to warrant a
GALE warning for PZZ676 tomorrow afternoon into the late night
hours.

Regarding PZZ673/670, it appears spatial coverage will be
adequate. However, it is uncertain if GALES will become widespread
or remain local. Thus, have held back off on a GALE warning and
will let the Mid-shift decide. For Monday and Tuesday, high
confidence in winds and seas remaining below SCA levels.

For the Inner Waters north of Point Sal, high confidence in
current forecast. There is a 80-90% chance of SCA level NW winds
Saturday during the afternoon and evening hours. On Sunday, there
is a 30-40% chance of SCA level winds in the afternoon and evening
hours. For Monday and Tuesday, high confidence in winds and seas
remaining below SCA levels.

For the Inner Waters south of Point Conception, moderate
confidence in current forecast. There is a 70% chance of SCA
level NW winds for the western portion of the Santa Barbara
Channel during the afternoon to late evening hours on Saturday.
SCA winds could linger for a few hours after midnight. Otherwise,
winds and seas are expected to remain below SCA levels through
Tuesday.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
PZ...Small Craft Advisory in effect until 9 PM PDT this evening
      for zones 645-650. (See LAXMWWLOX).
     Small Craft Advisory in effect until 9 PM PDT Sunday for
      zones 670-673. (See LAXMWWLOX).
     Small Craft Advisory in effect until 3 PM PDT Saturday for
      zone 676. (See LAXMWWLOX).
     Gale Warning in effect from 3 PM Saturday to 3 AM PDT Sunday
      for zone 676. (See LAXMWWLOX).

&&

$$

PUBLIC...JMB
AVIATION...Black
MARINE...Black
SYNOPSIS...JMB

weather.gov/losangeles

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