High Wind in California, June 14, 2021

Area Forecast Discussion
National Weather Service Los Angeles/Oxnard CA
156 PM PDT Mon Jun 14 2021

.SYNOPSIS...14/308 AM.

A significant heat wave is expected to be in full effect Tuesday
through the remainder of the week with peak high temperatures
expected Tuesday through Thursday. High temperatures will be 10
to 20 degrees warmer than normal. There will be gusty northerly
winds this afternoon and Tuesday, especially across the Santa
Barbara south coast and somewhat weaker through the Interstate 5
corridor. Some cooling inland by this weekend and a return of low
clouds should be limited to coastal areas by Friday morning.

&&

.SHORT TERM (TDY-THU)...14/154 PM.

Overall, 12Z models in very good synoptic agreement through the
short term period. Main feature of note is upper level high
building over the 4 Corners area through Wednesday then weakening
on Thursday which will bring some significant heat to the area.

First major concern for the short term is the potential for
Sundowner winds across southern SBA county. Models continue to
indicate stronger northerly gradients developing this evening and
continuing through Tuesday morning. The SBA-SMX is forecast to
peak around -5.0 MB and the SBA-BFl gradient at -6.5 MB. With
these type of gradients, widespread advisory level winds (gusts
35-55 MPH) are likely tonight/Tuesday morning with even a chance
of 60+ MPH gusts around Montecito. Given the expected winds, have
issued a WIND ADVISORY for southern SBA county from 600 PM this
evening through 900 AM Tuesday. For Tuesday night/Wednesday
morning, the northerly gradients are weaker, but still likely
strong enough to generate advisory-level Sundowner winds. So,
another advisory may be needed for that time period. Otherwise, do
not anticipate any significant wind issues with some sub-advisory
northerly winds through the I-5 Corridor.

Other concern for the short term will be the heat. With rising H5
heights and no marine layer stratus, temperatures will skyrocket
across the area. At this time, Tuesday looks to be the warmest day
for a majority of the area. On Wednesday, an increase in onshore
gradients will bring some slight cooling to coastal/valley areas
south of Point Conception, but the Central Coast looks to warm up
with some weak northeasterly flow in the morning. For Thursday,
there will be some minor changes in temperatures, but conditions
will still remain well above normal. So, the potential for
dangerous heat will continue. Current, EXCESSIVE HEAT WARNINGs AND
EXCESSIVE HEAT WATCHes will remain in effect. Please refer to
LAXNPWLOX for the latest details on the various heat products as
well as the wind advisories.

As for clouds, subsidence, associated with the upper level high,
will keep the marine layer squashed. So, little, if any, coastal
stratus/fog is anticipated. The upper level flow pattern remains
conducive to keeping the monsoon door open. However, models still
do not indicate any significant mid-level moisture surge.
Therefore, do not anticipate anything worse than some passing mid
to high level clouds through Thursday.

.LONG TERM (FRI-MON)...14/154 PM.

For the extended, the pattern looks rather benign. The main
feature of note will continue to be the upper level high over the
4 Corners area. Through the extended period, the high pressure
will gradually weaken and shift westward over the forecast
district. At the surface, varying amounts of onshore flow will
continue.

For the forecast, Friday looks to be the warmest day in the
extended with a continued potential for excessive heat conditions
across the valleys/mountains/deserts while a returning marine
layer keeps the coastal areas cooler. For Saturday through Monday,
a cooling trend for all areas is expected as the upper level high
continues to weaken and the marine layer stratus becomes more
extensive. Overall, just typical mid-June weather.

&&

.AVIATION...14/1820Z.

At 1759Z at KLAX, the marine layer was about 200 feet deep. The
top of the inversion was at 1900 feet with a temperature of 26 deg
C.

Expect skies to be mostly clear tonight across the region. Gusty
north winds will affect southern SBA County late this afternoon
through tonight with some LLWS, turbulence and mdt to stg UDDF.

KLAX...Moderate to high confidence in the 18Z TAF. There is a
10-20% chance of IFR cigs between 11Z and 16Z Tue.

KBUR...High confidence in the 18Z TAF with VFR conds thru the pd.

&&

.MARINE...14/1200 PM.

Across the southern two outer waters zones, (PZZ673/676), fairly
high confidence that Small Craft Advisory (SCA) level winds will
increase to Gale Force this afternoon then persist thru late Tue
night. Then, SCA conds will continue thru Thu, with a 40% chance
of SCA conds Fri. In the northern outer water zone (PZZ670),
winds are now expected to increase to GALE WARNING levels this
evening according to the most recent data, then persist thru Tue
night. SCA level winds are expected Wed night. There is a 40%
chance of SCA conds Thu thru Fri.

Across the inner waters north of Pt. Sal, SCA level winds are
likely this afternoon through late tonight, then during the
afternoon and evening hours Tue and Wed. However, seas may remain
at or above SCA levels during much of that time.

In the SBA Channel, SCA level winds and seas are likely across
much of the Channel late this afternoon thru tonight. There is a
30% chance of Gale Force winds across far western portions
this evening, but expect those to be localized. SCA conds are
likely across western portions of the SBA Channel Tue afternoon
and evening. SCA conds are not expected Tue night thru Fri.

Across the southern inner waters, widespread SCA conds are not
expected thru Fri. However, there will be some marginal SCA level
winds late this afternoon through late tonight across northern
and western portions, especially near Anacapa Island toward
Avalon, and a SCA will ultimately be needed.

Patchy dense fog with visibility of one nautical mile or less
will affect the waters this morning, especially across the
northern and outer waters.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...Excessive Heat Watch in effect from Wednesday morning through
      Wednesday evening for zones 34-35. (See LAXNPWLOX).
     Excessive Heat Warning in effect from 10 AM Tuesday to 9 PM
      PDT Wednesday for zones 36-44>46-88-547. (See LAXNPWLOX).
     Excessive Heat Watch in effect from Wednesday evening through
      Friday evening for zones 36-44>46-88-547. (See LAXNPWLOX).
     Excessive Heat Watch in effect from Wednesday morning through
      Friday evening for zones 37-38-51. (See LAXNPWLOX).
     Wind Advisory in effect from 6 PM this evening to 9 AM PDT
      Tuesday for zones 39-52. (See LAXNPWLOX).
     Excessive Heat Watch in effect from Tuesday morning through
      Wednesday evening for zones 39-41. (See LAXNPWLOX).
     Excessive Heat Warning in effect from 10 AM Tuesday to 9 PM
      PDT Friday for zones 52>54-59. (See LAXNPWLOX).
     Red Flag Warning in effect from 6 PM this evening to 6 AM PDT
      Wednesday for zones 239-252. (See LAXRFWLOX).
PZ...Small Craft Advisory in effect until 3 AM PDT Tuesday for
      zones 645-650-655. (See LAXMWWLOX).
     Small Craft Advisory in effect until 5 PM PDT this afternoon
      for zone 670. (See LAXMWWLOX).
     Gale Warning in effect from 5 PM this afternoon to 3 AM PDT
      Wednesday for zone 670. (See LAXMWWLOX).
     Gale Warning in effect until 3 AM PDT Wednesday for zones
      673-676. (See LAXMWWLOX).

&&

.HAZARD POTENTIAL OUTLOOK (THU-MON).

Gusty northerly winds will bring driving hazards and potentially
critical fire weather conditions Monday night through Tuesday over
southern Santa Barbara County. Very hot temperatures are expected
next week, especially inland, peaking Tuesday for the coast and
Wednesday and Thursday inland, with heat- related illness concerns.

&&

PUBLIC...Thompson
AVIATION...Sweet/DB
MARINE...Sweet
SYNOPSIS...Kaplan

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