High Wind in California, March 13 to 14, 2024

Area Forecast Discussion
National Weather Service San Diego CA
149 PM PDT Wed Mar 13 2024

.SYNOPSIS...
Strong and locally damaging Santa Ana winds will develop late
tonight and peak Thursday morning, with the strongest winds
occurring across a corridor from the San Bernardino County
Mountains through coastal Orange County. Winds will begin to
diminish Thursday night, but periods of breezy offshore winds will
continue this weekend. Showers and isolated thunderstorms will be
possible across the mountains each afternoon Thursday through
Sunday, with the highest chances developing on Friday, when cells
could drift into the valleys and deserts. Warmer and drier by
early next week.

&&

.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...

At 1 PM, mid-level clouds persist west of the mountains and high
clouds are moving in from the northwest. Current temperatures in
the valleys, mountains and lower deserts are around 5-10 degrees
warmer than on Tuesday, but are slightly cooler in the mountains
and High Desert. Surface pressure gradients are trending towards
neutral before turning offshore this evening.

A 547 DM low, currently centered over southern Idaho, will
progress southward tonight through Thursday, becoming anchored
over the Desert Southwest through this weekend. The low looks to
strengthen Thursday morning as it races in our direction, turning
winds strongly offshore. Winds look to peak Thursday morning,
with the strongest winds occurring across NW-SE oriented mountains
(San Bernardino and Orange Counties). Wind gusts of 80-90 mph
will be possible along the foothills and wind-prone passes
Thursday morning. Winds will also extend into the Inland Empire
and through Orange County, where damaging winds will also be
possible. Farther south into Riverside and San Diego Counties,
wind vectors will not be in a favorable direction for very strong
winds, but gusty conditions will still occur Thursday morning. The
ECMWF EFI is highlighting values of 0.5-0.9 and a shift of tails
up to 1 across a corridor from the San Bernardino County Mountains
through coastal Orange County, showing the potential for a strong
Santa Ana wind event. Thursday night into Friday, the low will
weaken and meander southward, allowing pressure gradients to
slowly relax and winds to diminish. Periods of offshore winds will
continue through the weekend, but will be weaker than on
Thursday.

As the low pressure system parks over the Southwest, moisture from
the Gulf of Mexico will wrap around the periphery, leading to
chances of showers and isolated thunderstorms each afternoon
Thursday through Sunday. The highest chances will occur over the
mountains, but cells may be able to drift into the eastern valleys
and deserts. The 12z ECMWF deterministic run shows the deepest
column of mid-level moisture on Friday, which will result in the
greatest chances for precipitation. Widespread accumulations are
not expected at this time, but weak steering flow aloft will lead
to slow storm movement, so locally heavy pockets of rain will be
possible. Lesser chances will exist by Saturday and Sunday as
upper-level winds and moisture profiles become less supportive of
convective development.

The low looks to slowly weaken and meander east starting on Sunday
before being overtaken by a building ridge across the West Coast.
Chances for measurable precipitation will fall below 10 percent
for Monday and Tuesday. High temperatures will warm for Sunday
through Tuesday with Tuesday high temperatures around 5 degrees
above average.

&&

.AVIATION...
132015Z...Coast/Valleys...SCT025-040 locally BKN025-040 through 04Z.
Skies clearing from north to south between 04Z-09Z. Strong northeast
winds 20-30 kt gusting 45 kt 09Z-23Z Thursday from KSBD/KONT toward
KSNA with strong UDDFS and LLWS.

Mountains/Deserts...Mostly clear tonight and Thursday. From 06Z-23Z
Thursday....northeast winds 20-40 kt with gusts to 70 kt with strong
UDDFS and LLWS.

&&

.MARINE...Gusty northeast winds to 25 knots over the coastal waters
Thursday from Orange County southward to Oceanside resulting in
hazardous boating conditions between Oceanside and San Clemente
Island.

&&

.SKYWARN...
Skywarn activation is not requested. However weather spotters are
encouraged to report significant weather conditions.

&&

.SGX WATCHES/WARNINGS/ADVISORIES...
CA...High Wind Warning from midnight tonight to 6 PM PDT Thursday for
     Orange County Coastal Areas-Orange County Inland Areas-San
     Bernardino County Mountains-San Bernardino and Riverside
     County Valleys-The Inland Empire-Santa Ana Mountains and
     Foothills.

     Wind Advisory from 2 AM to 2 PM PDT Thursday for Coachella
     Valley-Riverside County Mountains-San Gorgonio Pass Near
     Banning.

     Wind Advisory from midnight tonight to 6 PM PDT Thursday for
     Apple and Lucerne Valleys.

PZ...None.

&&

PUBLIC...EA
AVIATION/MARINE...Moede