890
FXUS66 KLOX 210936
AFDLOX
Area Forecast Discussion
National Weather Service Los Angeles/Oxnard CA
236 AM PDT Tue Jul 21 2026
.SYNOPSIS...21/213 AM.
Another heat wave is coming this week, peaking Thursday, but
remaining well above normal into early next week. There is
potential for major or extreme heat concerns for at least the
next week.
&&
.SHORT TERM (TDY-THU)...21/214 AM.
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...21/0914Z.
At 0831Z at KLAX, the marine layer was 700 ft deep. The top of
the inversion was at 1800 ft with a max temperature of 25 C.
High confidence in VFR TAFs for KBUR, KVNY, KPMD, KWJF, and KPRB.
Low confidence in the TAF for KSMX with a 40 percent chance of no
low clouds.
Moderate confidence in the remaining TAFs with a 30 percent chc
of IFR/LIFR cig/vis 12Z-16Z.
KLAX...Moderate confidence in TAF with a 30 percent chance of 2SM
OVC005 conds 12Z-16Z. No significant east wind component
expected.
KBUR...High confidence in VFR TAF.
&&
.MARINE...20/943 PM.
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 in
the western half of the Santa Barbara Channel 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...20/840 PM.
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 ENE 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 Tuesday. High Surf Advisories and Beach
Hazards Statements are in effect this evening 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 through this afternoon for
zones 340-346. (See LAXCFWLOX).
Heat Advisory remains in effect from 10 AM Wednesday to 8 PM
PDT Thursday for zones 349-350. (See LAXNPWLOX).
Extreme Heat Watch in effect from Thursday morning through
Monday evening for zone 383. (See LAXNPWLOX).
PZ...Small Craft Advisory in effect from 2 PM this afternoon to 3
AM PDT Wednesday for zone 650. (See LAXMWWLOX).
Small Craft Advisory in effect from 2 PM this afternoon to 3
AM PDT Thursday for zones 673-676. (See LAXMWWLOX).
&&
$$
PUBLIC...Rorke
AVIATION...Rorke
MARINE...Lewis/Ciliberti
BEACHES...Lewis/Ciliberti
SYNOPSIS...MW/CC
weather.gov/losangeles
Experimental Graphical Hazardous Weather Outlook at:
https://www.weather.gov/erh/ghwo?wfo=lox NWS LOX Office Area Forecast Discussion