Forecast Discussion

FXUS66 KLOX 242109

Area Forecast Discussion
National Weather Service Los Angeles/Oxnard CA
209 PM PDT Mon Jun 24 2024

.SYNOPSIS...24/209 PM.

There is a slight chance of thunderstorms across the interior
through this evening. A gradual cool down is expected through
midweek with temperatures potentially rebound into the weekend.
Low clouds and fog will likely redevelop across coastal areas by


.SHORT TERM (TDY-THU)...24/209 PM.

Excessive heat products with moderate to high heat impacts
continue through this evening for portions of the interior, except
through Tuesday evening for the Antelope Valley. We have high
confidence that cooling trends initiated today across the interior
will continue through Wednesday, decreasing heat impact to much
lower levels than we’ve experienced now for many areas for at
least several days. As such, we do not anticipate extending any of
the heat products.

The moisture associated with the mid cloud deck continues to
support a 5-15 percent chance (highest across the interior
Mountains and deserts) of a thunderstorm across the region today
with afternoon cumulus and a shower or two already showing up
along the high terrain. Dangerous cloud- to- ground lightning and
damaging wind would be the main concerns should a stronger
thunderstorm or two form with climatologically favored areas for
this being the eastern San Gabriel mountains into the Antelope
Valley and Ventura mountains west to the Santa Barbara mountains
(excluding the Santa Ynez Range). Generally weak flow aloft would
likely support slow storm movement towards the north or northeast
around 10 mph with anchoring or back building along the high
terrain possible. Any stalled thunderstorms may also produce
localized flash flooding.

Generally light onshore winds today will likely become stronger
with a west to northwest orientation Wednesday and Thursday,
potentially approaching advisory levels for southwest Santa
Barbara County and the mountains near the I-5 corridor.

Low confidence in low cloud and fog forecast as the marine layer
may struggle to reform as mid level moisture may stick around
until Tuesday or so. Sufficient moisture sticks around until at
least Tuesday afternoon to warrant a 5-10 percent chance of a
shower or thunderstorm across southwest California and the
adjacent waters.

.LONG TERM (FRI-MON)...24/208 PM.

Low confidence in the extended period. There is now a 60-70
percent chance that weak troughing will remain in place through
the weekend with building heat early next week. That does leave a
20-30 percent chance that heat builds as early as this weekend. If
the higher heat scenario plays out, there may be a monsoon push
into at least Los Angeles County early next week. Breezy west to
northwest winds will continue, peaking each afternoon and evening,
potentially nearing advisory levels for southwest Santa Barbara
County at times.



At 16Z over KLAX, the marine layer was 600 feet deep. The top of
the inversion was 3500 ft and 24 degrees Celsius.

There is a chance of -TSRA today: 20% chance at KSBP 16-19Z, KPRB
17-22Z, KWJF KPMD 20-02Z...10% chance KSBP KPRB 00-04Z. All other
sites have a low (5%) but non zero chance. Any thunderstorm will
likely produce brief gusty winds and little if any rain. There is
a chance of IFR/LIFR conditions tonight into Tuesday: 40% chance
at KSMX, 20% chance at KSBP KSBA, 10% chance at KOXR KSMO KLAX
KLGB. Otherwise, high confidence in VFR conditions into Tuesday.

KLAX...There is a 10% chance of IFR/LIFR conditions after 08Z
tonight. There is a 5% chance of -TSRA through early Tuesday, with
higher chances over the nearby mountains and deserts. Otherwise,
high confidence in VFR conditions. High confidence that any
southeast winds will remain under 8 knots.

KBUR...There is a 5% chance of -TSRA through early Tuesday, with
higher chances over the nearby mountains and deserts. Otherwise,
high confidence in VFR conditions.


.MARINE...24/119 PM.

The threat of isolated thunderstorms will remain through Tuesday
as moisture from the remnants of Tropical Storm Alberto linger
over the region. With dry air near the surface, any storm can
product brief but very gusty winds.

Dense fog with visibilities under one mile will remain a concern,
and while the coverage and shrunk a lot, expect some random
patches tonight into Tuesday.

There is a 30 percent chance of Small Craft Advisory (SCA) level
wind gusts tonight and Tuesday Night for the Outer Waters
(offshore waters of the Central Coast to San Nicolas Island).
Otherwise, high confidence in weaker than usual winds for this
time of the year. Northwest winds will increase Wednesday
afternoon through Thursday night. High confidence in SCA level
winds and steep seas for the Outer Waters, with a 20 percent
chance of reaching low-end Gale Force. 50 percent chance for SCA
winds and seas for the nearshore Central Coast waters, and a 20
percent chance for the western Santa Barbara Channel.


CA...Heat Advisory remains in effect until 8 PM PDT this evening
      for zones 38-344-345-348-353-379. (See LAXNPWLOX).
     Excessive Heat Warning remains in effect until 8 PM PDT this
      evening for zone 381. (See LAXNPWLOX).
     Excessive Heat Warning now in effect until 8 PM PDT Tuesday
      for zones 382-383. (See LAXNPWLOX).




Experimental Graphical Hazardous Weather Outlook at: