Duarte Weather

100
FXUS66 KLOX 031002
AFDLOX

Area Forecast Discussion
National Weather Service Los Angeles/Oxnard CA
302 AM PDT Mon Aug 3 2026

.SYNOPSIS...03/1203 AM.

Expect cooler conditions for the coast and coastal valleys
through much of this coming week, but with continued hot
conditions for the interior as above-normal temperatures
continue. Dense fog will affect some coastal areas.

&&

.SHORT TERM (TDY-WED)...03/232 AM.

Fairly uneventful summer weather will continue through the short
term. High pressure will remain overhead with slightly above
average hgts of 594 dam. The sfc gradients will also not change
much over the next three days. There will be mdt to stg onshore
flow to the east and weak to mdt onshore flow to the north.

Night through morning low clouds and fog will affect most of the
cstl areas everyday. The 594 dam hgts will smoosh the marine layer
enough to create pockets of dense fog, esp along the Central
Coast.

Max temps will continue to be the main talking point. The csts and
vlys will see a small cooling trend each day of 1 to 2 degrees.
Max temps will remain above normal, but not dangerously so. The
lower elevations of the mtns and the far interior will not be
affected by the marine layer or onshore flow and will continue to
see max temps from 100 to 110 degrees. Heat advisories and extreme
heat warnings are in effect for these areas through Wednesday.
PLease see the product LAXNPWLOX for details.

The strong onshore push in the afternoon will create gusty winds.
The gusts will not reach advisory levels but will come close in
the Antelope Vly where gusts 35 to 40 mph are expected.

.LONG TERM (THU-SUN)...03/232 AM.

The 500mb pattern does not change much Thursday and the day does
look similar to Wednesday. The mdls show just a smidgen of
cooling and depending on how the interior temps go Tue and Wed
there might not be a need for heat products.

The upper high strengthens on Friday and hgts over Srn CA rise to
597 dam. At the same time moisture increases with PWs over KLAX
increasing to 1.42" by Saturday afternoon. Some of the EC
ensembles also show a decrease in the onshore flow. Right now mdl
guidance does not show too much of an increase in temps, which
may well be the result of moister air not warming as quickly. The
more humid air will not allow for much overnight cooling. The
combination of increased humidity and warmer than normal highs and
lows will likely result in another round of heat advisories and
warnings.

Mdls do show the upper high weakening on Sun/Mon along with an
increase in onshore flow. This should bring two days of cooling.
Humidities, however, are forecast to remain elevated through at
least next Tuesday.

&&

.AVIATION...03/1002Z.

At 0822Z at KLAX, the marine layer was 1000 ft deep. The top of
the inversion was near 3100 feet with a temp of 27 C.

High confidence in VFR conds for KPRB, KBUR, KVNY, KPMD and KWJF.

Moderate confidence with the remaining TAFs. VFR transition
timing may be off by +/- 90 minutes. KSBA and south cigs may be
off by +/- 300 ft. There is a 30 percent chc of VLIFR conds at
KSMX and KSBP through 15Z.

KLAX...Moderate confidence in TAF. There is a 30 percent chc that
cigs will remain AOA 010. VFR conds could arrive as late as
1930Z. No significant east wind component expected.

KBUR...High confidence in CAVU TAF.

&&

.MARINE...03/259 AM.

For the inner waters north of Point Sal, there is a 40% chance of
SCA winds during through late tonight, highest along the Central
Coast. Otherwise conditions are expected to remain below SCA
levels across all nearshore waters.

For the Outer Waters, Small Craft Advisory (SCA) winds and seas
will continue through tonight before beginning to subside early
this coming week. There is a 30% chance that SCA winds will
resume near and south of Point Conception.

Seas of 6-9 feet will impact the outer waters through tonight,
due to a combination of long-period southerly swell and shorter-
period northwesterly swell/wind- waves. Seas will begin to
subside as the winds weaken late tonight into early next week.

Dense fog will affect some of the coastal waters each night and
morning through much of the week.

&&

.FIRE WEATHER...02/323 PM.

Today through Saturday, widespread elevated to brief critical
conditions will be common across the interior valleys, mountains,
and deserts due to hot, dry, and breezy onshore conditions with an
increased risk for large plume dominated fire behavior and rapid
fire growth due to deep mixing heights. For much of this week,
deep mixing heights of 10,000 to 17,000 feet can be expected
across the interior, with peak heights likely by mid to late week
as the atmosphere becomes slightly more unstable. If any fire
ignitions occur across the interior, these deeper mixing heights
will allow for large vertical plume growth, especially in the
mountains and foothills, where Live Fuel moisture levels are
approaching critical levels.

Other factors that will add to the fire weather risk across the
interior this week will be southwest to northwest winds 10 to 25
mph with gusts 20 to 35 mph, as well as widespread and long
duration single digit humidities. As a result, expecting at least
a few hours of wind/RH overlap to reach brief critical fire
weather conditions across many interior areas each afternoon and
early evening. There is a 20-30 percent chance of Red Flag
durations being reached (6+ hours) across portions of the interior
sometime between Tuesday and Saturday. The highest risk areas
include San Luis Obispo county interior mountains/valleys, Cuyama
Valley, Santa Barbara county interior mountains, Ventura county
interior mountains, and I-5 corridor. Hot-Dry-Windy index ensemble
solutions showing several model members exceeding 95th percentile
for multiple days across interior San Luis Obispo, Santa Barbara
county interior mountains, Ventura county interior mountains, and
I-5 corridor. In addition, there will be very poor to poor
overnight humidity recoveries, especially in the mountains and
foothills where some locations may continue to have humidities in
the teens.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...Extreme Heat Warning in effect from 10 AM this morning to 8
      PM PDT Tuesday for zones 38-377. (See LAXNPWLOX).
     Heat Advisory in effect from 10 AM this morning to 8 PM PDT
      Wednesday for zones 344-345-353-375-376-378>380. (See LAXNPWLOX).
     Extreme Heat Warning in effect until 8 PM PDT Wednesday for
      zones 381>383. (See LAXNPWLOX).
PZ...NONE.

&&

$$

PUBLIC...Rorke
AVIATION...Rorke
MARINE...Ciliberti
FIRE...Gomberg
SYNOPSIS...Ciliberti

weather.gov/losangeles

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

NWS LOX Office Area Forecast Discussion