Duarte Weather

735
FXUS66 KLOX 222126
AFDLOX

Area Forecast Discussion
National Weather Service Los Angeles/Oxnard CA
226 PM PDT Mon Jun 22 2026

.SYNOPSIS...22/225 PM.

A shallower marine layer is expected over the next few days and a
significant warming trend will continue through the next couple
days, peaking on Wednesday, with well above normal afternoon
temperatures. A push of moisture Tuesday and Wednesday will bring
at least a low chance for rain or an isolated storm from Ventura
County eastward and then drier conditions return. Temperatures
are then expected to cool heading into the end of the week and
the weekend.

&&

.SHORT TERM (TDY-THU)...22/222 PM.

One of the main points of emphasis in the short term forecast
continues to be the building hear the next few days. A strong and
broad high pressure over northern MX and the Desert Southwest is
slowly expanding into the area, and 500mb heights continue to
increase. Guidance continues to show heights will peak around
592-593dam by midday Tuesday. This will lead to continued surface
warming that looks like it will peak Tuesday and Wednesday before
gradually cooling back down, as the high pressure flattens with
increasing troffing across the West heading into late week.

Everything remains on track with a continuation of the Heat
Advisory for Tuesday through Thursday for portions of LA County
(interior coastal plain, valleys and mountains). Afternoon high
temperatures are forecast to be mostly around 3-8 degrees above
normal, with coastal areas forecast to reach the upper 70s to
upper 80s and low to middle 90s for inland valleys. These
temperatures will lead to widespread Minor HeatRisk and areas of
Moderate HeatRisk. Admittedly under normal conditions, these
temperatures would be marginal for any heat products. However
given the current influx of visitors and numerous outdoor events
across the county, there is a higher risk and vulnerability. There
will also be a small increase in surface moisture heading into
Tuesday that may add to the discomfort from the heat. The forecast
temperatures for Thursday continue to slowly trend down model run
to model run, with a quicker intrusion of troffing from the
northwest. So, will continue to monitor trends for whether the
advisory will be continue through Thursday.

Forecast with the mid-level moisture push Tuesday into Wednesday
remains on track. The bulk of the moisture is still expected to
stay just east and south of the area, but with PWATs still
pushing up to 125-175% of normal in portions of LA County. This
moisture flux is enough to still support at least low-end PoPs
(5-15%) Tuesday afternoon into Wednesday across LA and Ventura
counties. There will be a weak perturbation wave rolling through
the area, which will help steepen mid-level lapse rates.
Otherwise, there will not be much in the way of forcing with this
setup. Latest HREF/REFS runs all point to some spotty high-based
convection developing and staying east of LA County late Tuesday
into Wednesday morning. Main concern with any convection will be
gusty outflow winds and dry lightning. The layer below 700mb will
remain very dry, so a lot of the precipitation will likely
evaporate before reaching the ground.

Other than temperatures and shower chances, no significant issues
are expected through Thursday. The marine layer will remain,
impacting the coastal plain and lower coastal valleys. However the
areal extent each night should be a little bit less than the
night before. The layer will also be more shallow, which may lead
to more morning fog impacts. As for winds, there will continue to
be the gusty southwesterly winds across interior sections, but
any advisory level winds will remain localized in the desert
foothills.

.LONG TERM (FRI-MON)...22/222 PM.

For the extended period, models continue to exhibit good synoptic
agreement. At upper levels, trough will sag across the state with
cyclonic flow over the area through the weekend. At the surface,
moderate onshore flow will continue with some enhancement of
northerly offshore gradients next weekend.

Forecast-wise, no dramatic changes to current forecast thinking.
Friday through Sunday, the cyclonic flow aloft will usher in a
cooling trend for all areas with lowering thicknesses and
increased areal coverage of marine layer stratus. Typical onshore
winds will continue across interior sections each afternoon and
evening. However, with the increase in northerly offshore
gradients, there will be an increase in northerly winds across the
Santa Ynez Range and the I-5 Corridor. Winds across the western
half of the Santa Ynez Range could approach advisory levels next
weekend.

&&

.AVIATION...22/1722Z.

At 1610Z at KLAX, the marine layer was 2000 feet deep. The top of
the inversion was 3400 feet with a temperature of 17 C.

High confidence in VFR TAFs for desert airfields (KPMD & KWJF).

For all other sites, low to moderate confidence in 18Z TAFs.
Timing of CIG/VSBY restrictions may be off +/- 2 hours and
flight minimums by one category.

There is a 50% chance of LIFR CIGs at KPRB from 23/10-15Z.

KLAX...Moderate confidence in TAF. Timing of flight category
changes could be +/- 2 hours of current forecasts. No significant
east wind component is expected.

KBUR...Moderate confidence in TAF. VFR conditions expected.
However, there is a 10% chance of CIG/VSBY restrictions from
23/08-15Z.

&&

.MARINE...22/818 AM.

High confidence in winds and seas remaining below Small
Craft Advisory (SCA) levels through Wednesday. Local gusts
could reach 21 kts near Point Conception in the evening.
Moderate chances for SCA conditions return to the Outer Waters
Thursday afternoon/evening persisting into the weekend.
These conditions could reach into the nearshore waters along
the Central Coast and the Santa Barbara Channel at times.
Main concern is wind although seas could approach SCA levels
later into the weekend.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...Heat Advisory remains in effect from 8 AM Tuesday to 9 PM PDT
      Thursday for zones 88-368-372-373-379-380-548. (See LAXNPWLOX).
PZ...NONE.

&&

$$

PUBLIC...SB/Thompson
AVIATION...Black
MARINE...Black
SYNOPSIS...SB/CC

weather.gov/losangeles

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

NWS LOX Office Area Forecast Discussion