701
FXUS66 KLOX 041201
AFDLOX

Area Forecast Discussion...UPDATED
National Weather Service Los Angeles/Oxnard CA
501 AM PDT Thu Jul 4 2024

.SYNOPSIS...04/456 AM.

A significant heatwave will affect the region this week and will
continue through much of next week, with dangerously hot
temperatures across much of the area. High temperatures will reach
95 to 105 degrees in many areas away from the coast, and upwards
of 105 to 115 across interior valleys and foothills, including
the Antelope Valley. Patchy night to morning dense fog will affect
the coasts this morning and Saturday.

&&

.SHORT TERM (TDY-SAT)...04/415 AM.

An extended period of dangerously hot weather will continue across
much of the region into early next week. Not only will high
temperatures be dangerously high, but overnight temperatures will
remain elevated and limit any relief, especially for areas away
from the coast. This will be a time to limit exposure to the sun
(maybe even stay indoors) and make sure to stay hydrated.

The hot weather is a result of high pressure aloft continuing to
creep toward the West Coast and through Central California through
the weekend. Due to the high pressure, the marine layer influence
will be very shallow and remain limited to the coast through the
weekend allowing inland areas to warm up. However, there is a
small chance that clouds will linger at the beaches through the
day today and Saturday, but looks like it will clear out on Friday
due to weak northerly flow and offshore trends.

High temperatures today will increase a few degrees compared to
yesterday, but Friday is looking to have the biggest jump in high
temps with an increase of 5-15 degrees. The Santa Barbara South
Coast will warm 20 degrees due to northerly sundowner flow, except
lower at the immediate coast where a marine influence will most
likely prevail. Warmer coastal valleys will push close to 110 and
inland coastal areas in the 80s to low 90s. Deserts and other far
interior areas will be approaching or even locally exceeding 115.
These high temperatures will be up to 20 degrees above normal for
this time of year, and many daily record high temperatures may be
broken on Friday.

While Friday will be the hottest day with Saturday not far behind,
the duration of this event will likely produce an unprecedented
stretch of high temperatures over 110 degrees for the Deserts and
interior areas. The record for consecutive days at or above 110 is
three for Palmdale and Lancaster and five for Paso Robles. The
desert streak will almost certainly be crushed with the current
forecast showing highs over 110 for the next seven days.

.LONG TERM (SUN-WED)...04/501 AM.

As previously mentioned, the dangerously hot weather will
continue into next week with the upper level high pressure
persisting just to the north and east of the forecast area through
Wednesday. Temperatures will remain extremely high during that
time, but a weak trough will start to push into the region after
Wednesday causing coasts/coastal valleys to start to see slight
cooling (though still 5-10 degrees above normal) due to increasing
onshore flow. The onshore push will likely cause night through
morning clouds to expand further inland past the coasts,
contributing to the cooling. While the deserts may not see any
cooling, increasing winds with the onshore push may reach the
interior area, increasing fire danger there with the continued
extreme heat and hot and dry air mass.

&&

.AVIATION...04/0022Z.

At 00Z at KLAX, the marine layer was 800 feet deep. The top of
the inversion was at 3600 feet with a temperature of 31 Celsius.

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

Moderate confidence in remainder of TAFs. For coastal locations,
expecting IFR-VLIFR cigs/vsbys due to fog and low clouds returning
tonight. Cig/vsby restrictions dissipating from late to early
afternoon Thursday. Timing of flight category changes may vary by
+/- 2-3 hours of current forecasts, and there is up to a 30%
chance for minimum flight categories to be off by at least one
category.

KLAX...Moderate confidence in TAF. VLIFR conditions due to fog,
with a 30% chance cigs/vsbys will be 1-2 hours off in arrival and
clearing times. No significant easterly wind component is
expected.

KBUR...High confidence in TAF.

&&

.MARINE...04/432 AM.

In the Outer Waters, Small Craft Advisory (SCA) level winds will
develop in the southern zones (PZZ673/PZZ676) this afternoon, with
SCA winds continuing into Saturday morning. In the northern zone
(PZZ670), there is a 40% chance of SCA winds this afternoon/eve,
with SCA level winds expected Fri afternoon thru late Fri night.
There is a 30% chance of SCA level NW winds Sat afternoon/eve. SCA
conds are not expected Sat night thru Mon night.

For the Inner Waters north of Pt. Sal, SCA conditions are not
expected thru Mon night, except there is a 40% chance of SCA
winds Fri afternoon/eve.

For the Inner Waters south of Pt. Conception, SCA winds are likely
during the late afternoon thru late night hours today and Fri in
western portions of the Santa Barbara Channel. The area with the
greatest threat of SCA level winds is from Santa Cruz Island to
the SBA County south coast from Pt. Conception to Gaviota to
Refugio State Beach. Within this area, there is a 10-15% chance
of local Gale Force wind gusts just offshore from the immediate
coast late this afternoon thru late tonight.

Dense fog is expected to affect the coastal waters this morning,
and again late tonight and Fri morning. Please reference the
Marine Weather Statement for additional information.

&&

.BEACHES...04/501 AM.

A southerly swell front will overspread the Southern California
coastal waters today into Friday, followed by 15-17-second
southerly swell persisting from late this week into the weekend.
While surf is not expected to be particularly high, surf heights
upwards of around 5 feet are anticipated at beaches exposed to
southerly swell -- especially the LA and Ventura County beaches.
Moreover, significant wave energy with the long-period swell will
combine with the elevated surf to create dangerous conditions at
area beaches, with powerful and dangerous rip currents expected.
This is especially the case for the beaches of LA and Ventura
Counties. A Beach Hazards Statement is in effect from mid-day
today through the weekend to address these concerns.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...Excessive Heat Warning remains in effect until 6 PM PDT
      Wednesday for zones 38-343>345-353-376>379-381>383. (See LAXNPWLOX).
     Excessive Heat Warning remains in effect until 6 PM PDT
      Monday for zones 88-342-348-351-352-356>358-369>375-380. (See LAXNPWLOX).
     Heat Advisory remains in effect from 11 AM this morning to 6
      PM PDT Sunday for zones 341-347-355-368. (See LAXNPWLOX).
     Excessive Heat Warning remains in effect from 11 AM this
      morning to 6 PM PDT Saturday for zones 349-350. (See LAXNPWLOX).
     Beach Hazards Statement in effect from 11 AM PDT this morning
      through Sunday evening for zones 354-362-366. (See LAXCFWLOX).
     Heat Advisory remains in effect until 6 PM PDT Sunday for
      zone 548. (See LAXNPWLOX).
     Fire Weather Watch in effect from Friday morning through late
      Friday night for zones 342>345. (See LAXRFWLOX).
     Red Flag Warning in effect from 6 PM this evening to 6 AM PDT
      Saturday for zones 349-351>353-376>378-381. (See LAXRFWLOX).
PZ...Small Craft Advisory in effect from 3 PM this afternoon to 2
      AM PDT Friday for zone 650. (See LAXMWWLOX).
     Small Craft Advisory in effect from 3 PM Friday to 3 AM PDT
      Saturday for zone 670. (See LAXMWWLOX).
     Small Craft Advisory in effect from 3 PM this afternoon to 9
      AM PDT Saturday for zones 673-676. (See LAXMWWLOX).

&&

$$

PUBLIC...Lund/DB
AVIATION...Lewis/Phillips/Cohen
MARINE...DB
BEACHES...Cohen
SYNOPSIS...MW/KL

weather.gov/losangeles

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