South Whittier, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

632
FXUS66 KLOX 160319
AFDLOX

Area Forecast Discussion
National Weather Service Los Angeles/Oxnard CA
819 PM PDT Sun Mar 15 2026

.SYNOPSIS...15/617 PM.

A significant heat wave will affect the region through the coming
week, peaking on Tuesday and Wednesday, and then continuing
through Friday. MODERATE to HIGH heat impacts will occur each day
this week.

&&

.SHORT TERM (SUN-WED)...15/813 PM.

***UPDATE***

High temperatures today were the coolest the region will see
through at least Saturday. Marine layer clouds are currently
developing over the coastal waters and may end up fairly
widespread across the beaches south of Point Conception by early
morning. No major changes with the evening update, and the
significant heat wave remains on track.

***From Previous Discussion***

Overall, 12Z models exhibit good synoptic agreement through the
short term period. At upper levels, high pressure will strengthen
over the area with heights peaking in the 590-594 DM range. At the
surface, weak diurnal flow (offshore night/morning and onshore
afternoon/evening) is forecast.

With this pattern, the area is still very much on track for a
historic, long-duration, heat event. On Monday, temperatures will
climb into the 80s to mid 90s for all areas. Based on Heat Risk
calculations, HEAT ADVISORIES still look good for all coastal and
coastal valleys as well as the mountains.

For Tuesday and Wednesday, the heat will continue to build as the
upper level high pressure strengthens. For areas away from the
coast, temperatures will climb into the mid 90s to low 100s.
However across immediate coastal areas, high temperatures are a
bit more uncertain due to their dependence on the surface pressure
gradients and are currently forecast to be in the mid 80s to mid
90s. So, based on the Heat Risk calculations, will upgrade to an
EXTREME HEAT WARNING through Wednesday for all coastal valley
zones (except the Santa Ynez Valley), the mountains as well as
the interior LA coast. For the remainder of the coastal zones, as
well as the Santa Ynez Valley, will go with HEAT ADVISORIES for
Tuesday and Wednesday. However, if the offshore gradients are a
bit stronger, some of these coastal zones could be pushed into
warning levels. As for overnight low temperatures, there will be a
steady warming trend through Wednesday, compounding the
uncomfortable nature of this pattern.

Other than temperatures, no significant issues are expected. Based
on high resolution models and the HREF, there may be some
additional stratus/fog across the LA coastal plain tonight and
Monday morning. Otherwise, clear skies are expected through
Wednesday.

BOTTOM LINE...

THIS UPCOMING HEAT EVENT IS FORECAST TO BE AN HISTORIC EVENT,
LIKELY BREAKING MANY DAILY AND EVEN MONTHLY TEMPERATURE RECORDS.

IF YOU OR SOMEONE YOU KNOW IS AT RISK FOR HEAT-RELATED PROBLEMS,
PLEASE MAKE COOLING PLANS FOR THE UPCOMING WEEK.

.LONG TERM (THU-SUN)...15/201 PM.

For the extended, 12Z models continue to exhibit good synoptic
agreement through the period. Main feature of note will continue
to be the very strong upper level high pressure will continue to
slowly drift southeastward Thursday/Friday, before being flattened
on Saturday/Sunday as a weak system moves across the West Coast.

Forecast-wise, main issue will continue to be the historic heat
event. Based on all available data, the oppressive heat will
continue through Friday, before relenting on Saturday/Sunday. So
for Thursday and Friday, will continue with the same configuration
of EXTREME HEAT WARNINGS and HEAT ADVISORIES from the mountains
westward. Again as mentioned in the short term discussion,
depending on the strength of the surface pressure gradients, some
coastal zones could bump up to warning levels on Thursday and
Friday. So, will continue to monitor that potential very closely.

For Saturday, there is a 50% chance that some heat products will
need to extended through the evening hours, mainly inland from the
beaches. However by Sunday, things should cool down rather
noticeably. Therefore, no heat products are anticipated.

As for rain chances, deterministic models (and their respective
ensembles) indicate some possibility of light showers after the
25th. However, no significant storms are indicated for Southern
California through the end of the month.

&&

.AVIATION...16/0115Z.

At 0040Z at KLAX, there was no marine layer. There was an
inversion with a top near 1600 ft and a temperature of 26 C.

High confidence in TAFs for KPRB, KSBP, KSMX, KBUR, KVNY, KPMD and
KWJF.

Low confidence between 06Z-18Z for coastal sites KSBA to KLGB
including KLAX with a 40-50 percent chance that VFR conds prevail.

KLAX...High confidence in the 00Z through 06Z then low confidence
through 18Z due to uncertainty in the arrival time and height of
CIGs. There is a 20 percent chance of IFR conds between 06-08Z,
and also a 20% chance of LIFR conds between 08Z-15Z. Otherwise,
40% chance that VFR conds prevail. High confidence that any east
wind component will be below 7 kts.

KBUR...High confidence in VFR 00Z TAF.

&&

.MARINE...15/816 PM.

Small Craft Advisory (SCA) conditions will linger into late
tonight across the Outer Waters near and north of Point Conception.
Thereafter, conditions will likely remain benign through at least
mid-week. Moderate chances for SCA winds starting Thursday or
Friday across the northernmost outer waters.

For the Inner waters along the Central Coast, conditions are
expected to remain below SCA levels through late this coming week.
Inside the Southern California Bight, conditions are expected to
remain below SCA levels for the foreseeable future.

Dense fog is possible at times this week.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...Heat Advisory remains in effect from 10 AM Monday to 10 AM
      PDT Tuesday for zones
      87-88-340>342-345>358-362-366>376-378>380-548. (See LAXNPWLOX).
     Heat Advisory now in effect from 10 AM Tuesday to 8 PM PDT
      Friday for zones
      87-340-341-346>350-354-355-362-366-367-549-550. (See LAXNPWLOX).
     Extreme Heat Warning in effect from 10 AM Tuesday to 8 PM PDT
      Friday for zones
      88-342-345-351>353-356>358-368>376-378>380-548. (See LAXNPWLOX).
     Beach Hazards Statement in effect through Wednesday evening
      for zones 354-362-366. (See LAXCFWLOX).
PZ...Small Craft Advisory in effect until 3 AM PDT Monday for
      zones 670-673. (See LAXMWWLOX).

&&

$$

PUBLIC...Thompson/Schoenfeld
AVIATION...Ciliberti
MARINE...Ciliberti
SYNOPSIS...RAT/CC

weather.gov/losangeles

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