146
FXUS66 KLOX 211803
AFDLOX

Area Forecast Discussion...UPDATED
National Weather Service Los Angeles/Oxnard CA
1103 AM PDT Tue Jul 21 2026

.SYNOPSIS...21/944 AM.

Hotter than normal conditions will dominate the foreseeable
future. The hot daytime and warm night conditions will bring
elevated risks for heat illness. Thursday through Sunday will
generally be the hottest of the next seven days. Gusty north winds
expected Wednesday through Friday.

&&

.SHORT TERM (TDY-THU)...21/948 AM.

***UPDATE***

The forecast is generally on track. Increased temperatures on the
Central Coast for today, as the lack of a marine layer and
tropical airmass is currently trending temperatures 10 to 15
degrees up from 24 hours ago. Elsewhere, temperatures will be
around normal for today. Should see some afternoon cloud buildups
in the mountains, but the chance for any showers or thunderstorms
is under 10 percent. Will make a few changes in the next couple of
hours on the current suite of Heat Advisories and Watches. The
timing remains on track, and will likely lean more into Heat
Advisories than Warnings.

***From Previous Discussion***

Heat is going to be major and only talking point through the
short and long term. The primary driver of the heat will be a very
warm upper high centered over nrn Texas whose western extent
pushes over the state with 594 dam hgts. At the sfc - mdt to stg
onshore flow to the east will weaken to lgt to mdt by Thu. There
will be weak onshore flow to the north today but it will be
turning offshore perhaps by Wednesday, but definitely by Thursday.

Mid level clouds and moisture from Elida have disrupted the marine
layer and most areas should be low cloud free this morning. Max
temps will rise 1 or 2 degrees today and will end up 2 to 4
degrees above normal except on the Central Coast where max temps
in the upper 70s to mid 80s will be about 6 degrees over normals.

The heat kicks into gear on Wednesday as the weakening onshore
trends begin. Mdls still show a high probability of a coastal
marine layer stratus pattern, but given the lack of low clouds
this morning and no real sign of an eddy would not be surprised to
see much less in the way of low clouds. Whatever low cloud there
will be they will be gone by mid morning. Look for 1 to 2 degrees
of warming across the csts with 3 to 6 degrees elsewhere. Heat
Advisories start at 1000 am for much of non coastal areas. Extreme
Heat Watches them begin in the evening.

Please see the product LAXNPWLOX for all of the heat details and
timing information.

Above normal nearshore sea sfc temps and higher than normal PWATs
from the two tropical systems passing to the west will keep
humidities elevated which will keep overnight lows uncomfortably
warm.

Another 2 to 3 degrees of warming on Thursday will bring max
temps in the upper 70s to the beaches; 80s and lower 90s to the
rest of the csts; 90 to 101 degrees in the vlys except for the
western San Fernando Vly where temps will reach up to 106 degrees;
the lower mtn elevations and far interior sections will
experience highs 100 to 107 degrees.

Gusty Sundowner winds are expected across southern Santa Barbara
County each evening. These downsloping winds will bring very warm
evening temps and overnights to portions of the SBA south coast
extending to the beaches at times.

Due to this stretch of heat and humidity... It`s strongly
recommended that outdoor activities are confined to the early
morning and evening hours.

.LONG TERM (FRI-MON)...21/213 AM.

The upper high migrates westward starting Friday and sets up shop
over the 4 corners region. Hgts will increase a few more mb.
Offshore flow will continue from the north while onshore flow will
persist to the east. Unsure how much stratus there will be each
morning if there is any it will be confined to the nearshore area
as the higher than normal hgts will keep any marine layer smooshed
to under 900 ft. Mdl consensus shows cooling on Friday although
there are not many synoptic signals for cooling and would not be
too surprised if the cooling is less than fcst.

In general there will be little day to day change. Humidities will
continue to be above normal. Max temps will change little day to
day. Overnight lows will also continue to be above normal and
humid to boot. Heat advisories will likely continue through the
period. Citizens need to prepare for a long duration heat wave.

Since the upper high will be in the 4 corners area there will be a
non zero chc of monsoon convection. Right now there is mdl
indication of convection but that can change and will be watched.

&&

.AVIATION...21/1802Z.

Around 18Z at KLAX, the marine layer was 1800 ft deep. The top of
the inversion was at 3500 ft with a max temperature of 22 C.

High confidence in VFR TAFs for KPMD, KWJF, and KPRB. There is a
10 percent chance of LIFR-IFR conds at KPRB 08Z-17Z Wed.

High confidence in the remaining TAFs through 03Z, then low to
moderate confidence. There is a 30 percent chance of IFR/LIFR
cig/vis 04Z-18Z Wed for the coastal TAFs, and a 20 percent chance
10Z-15Z Wed for KBUR and KVNY.

KLAX...High confidence through 06Z, then low to moderate
confidence in TAF. There is a 30 percent chance of 2SM OVC005
conds 07Z-18Z Wed. No significant east wind component expected.

KBUR...High confidence through 09Z, then moderate confidence in
TAF. There is a 20 percent chance of 2SM OVC005 conds 07Z-18Z Wed.

&&

.MARINE...21/834 AM.

Conditions are generally expected to remain below Small Craft
Advisory (SCA) levels through this morning. Northwest winds will
strengthen, rising to SCA levels by the afternoon, and will
likely continue through the rest of the week and into the weekend.
Chances also increase for SCA level west to northwest winds across
the western half of the Santa Barbara Channel each afternoon and
evening during the same time.

A series of moderate period southerly swells will move through
the waters through the week and likely beyond, along with a long
period southern hemisphere swell arriving late this week. These
swells may impact south facing harbors, including the Port San
Luis area.

&&

.BEACHES...21/852 AM.

Over the eastern Pacific, the remnants of Tropical Storm Elida
are forecast to continue moving north-northwest well off the
California Coast. In addition, Hurricane Fausto, located 700 NM SW
of southern Baja, will move WNW between 15 to 20 N latitude
through the next 5 days or longer. This system will produce
additional, moderate period southerly swell that will begin to
move into the waters late tonight, but not expecting this swell to
be too impactful to the beaches. Therefore, High Surf Advisories
and Beach Hazards Statements are in effect through Tuesday night.

Finally, an incoming long period, southern hemisphere swell
arriving later this week/Thursday night will contribute to
continued and potentially more hazardous beach conditions late
this week and next weekend. Additional High Surf Advisories and/or
Beach Hazards Statements will likely be needed during this time.

Looking beyond the forecast period, a series of tropical systems
are forecast to develop off the coast of Mexico and move to the
northwest, likely producing multiple rounds of southerly swells
over the next couple of weeks.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...Heat Advisory remains in effect from 10 AM Wednesday to 8 PM
      PDT Monday for zones 38-348-351>353-368. (See LAXNPWLOX).
     High Surf Advisory in effect until 11 PM PDT this evening for
      zones 87-354-362-366. (See LAXCFWLOX).
     Heat Advisory remains in effect from 10 AM to 8 PM PDT
      Wednesday for zones 88-356>358-369>382-548. (See LAXNPWLOX).
     Extreme Heat Watch in effect from Wednesday evening through
      Monday evening for zones 88-356>358-369>382-548. (See LAXNPWLOX).
     Beach Hazards Statement in effect until 5 PM PDT this
      afternoon for zones 340-346. (See LAXCFWLOX).
     Heat Advisory in effect from 10 AM Wednesday to 8 PM PDT
      Monday for zones 342>345. (See LAXNPWLOX).
     Heat Advisory remains in effect from 10 AM Wednesday to 8 PM
      PDT Thursday for zones 349-350. (See LAXNPWLOX).
     Extreme Heat Warning in effect from 10 AM Thursday to 8 PM
      PDT Monday for zone 383. (See LAXNPWLOX).
PZ...Small Craft Advisory in effect until 3 AM PDT Wednesday for
      zone 650. (See LAXMWWLOX).
     Small Craft Advisory in effect until 3 AM PDT Thursday for
      zones 673-676. (See LAXMWWLOX).

&&

$$

PUBLIC...Rorke/RK
AVIATION...Lund
MARINE...Lewis/Ciliberti
BEACHES...Lewis/Ciliberti
SYNOPSIS...RK

weather.gov/losangeles

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