002
FXUS66 KLOX 132053
AFDLOX

Area Forecast Discussion
National Weather Service Los Angeles/Oxnard CA
153 PM PDT Fri Mar 13 2026

.SYNOPSIS...12/1139 PM.

A heat wave is expected to continue to affect the region through
Sunday, aside from minor cooling on Saturday. For next week,
significant additional warming is likely, with potential for
MODERATE to HIGH heat impacts as a very strong ridge of high
pressure builds over the area. Heat stress will be a threat each
day.

&&

.SHORT TERM (TDY-MON)...13/152 PM.

Overall, 12Z models in good synoptic agreement through the short
term period. At upper levels, ridge will continue to weaken this
afternoon through Saturday, but will start to rebuild from the
west on Sunday and Monday. Near the surface, onshore flow will
increase this afternoon through Saturday, but offshore flow will
begin to reestablish on Sunday and Monday.

Forecast-wise, main issue through the short term will continue to
be temperatures. With return of onshore flow and weakening high
pressure aloft, temperatures will be noticeably cooler on Saturday
(but still remain 6-12 degrees above normal). So, will continue
with the HEAT ADVISORIES through this evening with no advisories
expected on Saturday. On Sunday and Monday, the increasing
offshore surface flow and building upper level ridge will start
the return of significant heat to the area. On Sunday, high
temperatures will increase about 3-8 degrees, but are expected to
remain below advisory levels. On Monday, temperatures will
continue to rise, climbing into the mid 80s to mid 90s across the
entire area. Overnight low temperatures will also exhibit a
warming trend. Given the expected temperature conditions on
Monday, an EXTREME HEAT WATCH has been issued for all coastal and
coastal valley areas.

Otherwise, no significant issues are expected through the short
term period. High clouds aloft will bring partly cloudy conditions
to the area through this evening, but will thin out on Saturday
with mostly clear conditions expected for most areas through
Monday. With the return of onshore flow tonight, and the potential
for a weak eddy, there is a decent chance of some marine layer
stratus tonight/Saturday morning across the LA coast as well as
the Lompoc/Santa Maria area. For Saturday night, the "threat` of
any stratus/fog will be confined to the LA county coast. As for
winds, there will be some gusty northerly winds on Saturday and
Saturday night in the usual areas (I-5 Corridor and Santa Barbara
county mountains), but any advisory-level winds are expected to
remain localized. On Sunday and Monday, the increasing offshore
gradients will generate some locally gusty northeasterly winds,
but chances for advisory-level issues is low at this time.

.LONG TERM (TUE-FRI)...13/152 PM.

For the extended, 12Z models still on track with the synoptic
pattern. At upper levels, impressive high will develop over the
area Tuesday/Wednesday then slowly drift to the southeast on
Thursday/Friday. Near the surface, models still exhibit the same
differences as previous runs...with the GFS indicating weak
diurnal flow while the ECMWF indicates weak offshore flow.

With this pattern, the entire area is still on track for a
historic March heat event next week. Once again, here are the
details that make this such an extreme event:

1. 500 MB heights are forecast to range between 590 and 594 DM
which would be the highest March H5 heights since records began in
1948. The record is 591 dam which occurred on March 7

2. 1000-500 MB thickness are forecast to peak in the 580 to 583
DM range. Based on the 25+ year history of TEMP STUDY, the highest
thicknesses recorded in March are 576 dam.

3. The Extreme Forecast Index (EFI) indicates values between 0.8
and 1.0 for both Maximum and Minimum temperatures, signifying a
very usual or extreme event.

4. If the weak offshore flow, forecasted by the ECMWF, pans out
then temperatures west of the mountains could be higher than
currently forecast.

5. Based on current forecasts, both daily and monthly March
temperatures records could fall for most climate sites.

6. Max temps during this period will be 20 to 30 degrees above
normal.

With little change in the overall forecast, confidence remains
very high with a near 100% chance of HEAT ADVISORIES for most
areas in the Tuesday through Friday time frame. Additionally, the
chances for extreme heat are growing, so EXTREME HEAT WATCHES have
been issued from Tuesday through Friday for all coastal and
coastal valley zones. Over the weekend, the WATCHES may be
expanded into interior sections.

Given the unprecedented length and magnitude of this extreme heat
wave, heat stress will be a real threat each day, especially in
areas that aren`t used to the heat, like the coastal areas, where
people may not have methods to cool off their homes. Try to
complete outdoor activities early in the day or in the evening,
and don`t leave people or pets in cars.

As for any rain chances, deterministic and ensembles do not
indicate any chances for significant rain through the 28th.

&&

.AVIATION...13/1150Z.

At 0850Z at KLAX, there was no marine layer. There was a sfc based
inversion with a top at 1100 ft and a temperature of 28 C.

High confidence in TAFs, except for KLAX, KLGB and KSMX where LIFR
conds are possible as early as 14/09Z, but also a 30 percent chc
of no flight restrictions.

KLAX...High confidence VFR TAF through 09Z then lower confidence.
1/2SM VV002 conds could arrive as early as 09Z. There is also a
30 percent chc of no cig/vis restrictions. No significant east
wind component expected.

KBUR...High confidence TAF.

&&

.MARINE...13/708 AM.

Small Craft Advisory (SCA) level NW-N winds of 20-30 kt are
likely across the Outer Waters through Sunday night. Seas will
peak near 10 ft (especially beyond 40 NM from shore) during this
period. Have upgraded to a GALE Warning for PZZ670, Wind gusts to
35 kt are likely from this evening through late Saturday night.
Confidence is lower for PZZ673/676, so will hold off and pass to
next shift for further consideration. Conditions are likely to
improve early next week, with relatively small seas expected.

SCA level NW winds will affect the Inner Waters along the Central
Coast during the afternoon and evening hours today and Saturday,
with a 30% chance SCA winds linger into Sunday.

Inside the Southern California Bight, conditions are expected to
remain below SCA levels for the foreseeable future, except for
a moderate chance winds reach SCA levels Saturday afternoon and
evening across the western portion of the Santa Barbara Channel.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...Extreme Heat Watch in effect from Monday morning through
      Friday evening for zones
      87-88-340>342-346>352-354>358-362-366>375-548>550. (See LAXNPWLOX).
     Heat Advisory remains in effect until 8 PM PDT this evening
      for zones 88-340>342-346>352-354>358-362-366>375-548. (See LAXNPWLOX).
PZ...Small Craft Advisory in effect until 3 AM PDT Saturday for
      zones 645-676. (See LAXMWWLOX).
     Small Craft Advisory in effect until 9 PM PDT this evening
      for zones 670-673. (See LAXMWWLOX).
     Gale Warning in effect from 9 PM this evening to 3 AM PDT
      Sunday for zone 670. (See LAXMWWLOX).
     Gale Watch in effect from 9 PM PDT this evening through late
      Saturday night for zone 673. (See LAXMWWLOX).
     Gale Watch in effect from late tonight through late Saturday
      night for zone 676. (See LAXMWWLOX).

&&

$$

PUBLIC...Thompson/Rorke
AVIATION...Rorke
MARINE...Black/RAT
SYNOPSIS...RAT/CC

weather.gov/losangeles

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

NWS Los Angeles (LOX) Office