Special Marine Warning 5, NWS San Diego, CA

Area Forecast Discussion
National Weather Service San Diego CA
210 PM PDT Fri Sep 24 2021

.SYNOPSIS...
An area of low pressure will stick around our area through the
weekend. This will lead to cloudier conditions with cooler weather
along with the chance for showers and thunderstorms area wide. As
the system departs, a large trough of low pressure will enter the
Pacific Northwest and slowly nudge its way into California. This
will bring greater onshore flow and more cooler weather for the
region through the middle of next week.

&&

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

.SHORT TERM...(Today through Sunday)...
An upper level area of low pressure is currently circulating over
Northern Baja California. This has been associated with moist east
and north flow, where thunderstorms have developed this morning
and continue currently over much of the region. The atmosphere
will be unstable enough today into early for support of isolated
showers and thunderstorms in the western valleys and the coastal
areas as well. Storms may produce areas of heavy rain that may
lead to flash flooding for the Riverside and San Diego County
mountains/deserts.

Storm chances will decrease a bit for Saturday as the low shifts
slightly south, where storms will mainly be confined to the
mountains and deserts per latest WRF/HRRR guidance. As the low
pressure system slowly pushes east on Sunday, the atmosphere will
loose a bit of instability and lift, so storms have a lesser
chance popping up across the mountains and lower deserts.
Temperatures will also continue to decrease through the weekend
where we will see most areas around 5 degrees below average by
Sunday.

&&

.LONG TERM...(Monday Onward)...
After the low pressure system departs, a trough will begin to
enter the Pacific Northwest by Monday. As the system heads south
and east, it will continue to bring cooler air and breezy
conditions to the mountains and deserts by Tuesday and Wednesday.
Pressure gradients tighten on Tuesday, where windy conditions will
be most pronounced across the mountains and deserts. Some areas
may see west winds gust over 50 MPH through favored passes and
canyons. Wednesday looks to be the coolest day overall with high
temperatures 5-15 below average expected. Differences in model
agreement start to emerge as we get toward the end of the week,
but for now, looks to stay dry with temperatures near average.

&&

.AVIATION...
242043Z...Coast and offshore...OVC008-012 with tops near 1500 FT MSL
developing over the coastal water...and after 25/03z this evening
moving inland. SCT-BKN100 with LCL VIS 5SM in ISOLD SHRA/-TSRA and
CB bases near 6000 feet MSL will taper off slowly after 25/02z this
evening.

Valleys/Mountains/Deserts...SCT-BKN100 with SCT SHRA/TSRA forming
over the mountains, some of which will drift west over the valleys
with bases 060-100 and tops to FL400. The stronger thunderstorms
will briefly lower cloud bases to BKN-SCT at around 6000 feet MSL in
+RW that will severely restrict visibility, along with gusty and
erratic winds. Activity decreasing slowly after about 25/03z this
evening.

&&

.BEACHES...
Scattered showers and thunderstorms are possible at the beaches
through early evening today, especially in San Diego County.

&&

.MARINE...
There is a high probability of no significant weather over the
coastal waters through Monday. However, a small chance does exist
for a few showers and thunderstorms, in association with a
developing upper-level low pressure system off the Baja Ca Coast
from late Friday through Sunday morning.

&&

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

&&

.SGX WATCHES/WARNINGS/ADVISORIES...
CA...Flash Flood Watch until 7 PM PDT this evening for Coachella
     Valley-Riverside County Mountains-San Diego County Deserts-
     San Diego County Mountains.

     Beach Hazards Statement until 7 PM PDT this evening for Orange
     County Coastal Areas-San Diego County Coastal Areas.

PZ...NONE.
&&

PUBLIC...APR
AVIATION/MARINE/BEACHES...Small

<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>Service Notice</title>
  <link rel="stylesheet" href="index.css">
</head>
<body>
  <main class="wrap">
    <section class="card" role="status" aria-live="polite">
      <div class="status" id="status">Temporary Notice</div>
      <h1 id="headline">This service is currently unavailable.</h1>
      <p id="message1">
        The site you requested is temporarily down for maintenance or an unexpected outage.
      </p>
      <p id="message2">
        Please try again in a few minutes.
      </p>
      <p class="small" id="detail">
        If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
      </p>
    </section>
  </main>
  <script src="index.js"></script>
</body>
</html>

<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>Service Notice</title>
  <link rel="stylesheet" href="index.css">
</head>
<body>
  <main class="wrap">
    <section class="card" role="status" aria-live="polite">
      <div class="status" id="status">Temporary Notice</div>
      <h1 id="headline">This service is currently unavailable.</h1>
      <p id="message1">
        The site you requested is temporarily down for maintenance or an unexpected outage.
      </p>
      <p id="message2">
        Please try again in a few minutes.
      </p>
      <p class="small" id="detail">
        If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
      </p>
    </section>
  </main>
  <script src="index.js"></script>
</body>
</html>

<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>Service Notice</title>
  <link rel="stylesheet" href="index.css">
</head>
<body>
  <main class="wrap">
    <section class="card" role="status" aria-live="polite">
      <div class="status" id="status">Temporary Notice</div>
      <h1 id="headline">This service is currently unavailable.</h1>
      <p id="message1">
        The site you requested is temporarily down for maintenance or an unexpected outage.
      </p>
      <p id="message2">
        Please try again in a few minutes.
      </p>
      <p class="small" id="detail">
        If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
      </p>
    </section>
  </main>
  <script src="index.js"></script>
</body>
</html>

<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>Service Notice</title>
  <link rel="stylesheet" href="index.css">
</head>
<body>
  <main class="wrap">
    <section class="card" role="status" aria-live="polite">
      <div class="status" id="status">Temporary Notice</div>
      <h1 id="headline">This service is currently unavailable.</h1>
      <p id="message1">
        The site you requested is temporarily down for maintenance or an unexpected outage.
      </p>
      <p id="message2">
        Please try again in a few minutes.
      </p>
      <p class="small" id="detail">
        If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
      </p>
    </section>
  </main>
  <script src="index.js"></script>
</body>
</html>

<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>Service Notice</title>
  <link rel="stylesheet" href="index.css">
</head>
<body>
  <main class="wrap">
    <section class="card" role="status" aria-live="polite">
      <div class="status" id="status">Temporary Notice</div>
      <h1 id="headline">This service is currently unavailable.</h1>
      <p id="message1">
        The site you requested is temporarily down for maintenance or an unexpected outage.
      </p>
      <p id="message2">
        Please try again in a few minutes.
      </p>
      <p class="small" id="detail">
        If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
      </p>
    </section>
  </main>
  <script src="index.js"></script>
</body>
</html>

<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>Service Notice</title>
  <link rel="stylesheet" href="index.css">
</head>
<body>
  <main class="wrap">
    <section class="card" role="status" aria-live="polite">
      <div class="status" id="status">Temporary Notice</div>
      <h1 id="headline">This service is currently unavailable.</h1>
      <p id="message1">
        The site you requested is temporarily down for maintenance or an unexpected outage.
      </p>
      <p id="message2">
        Please try again in a few minutes.
      </p>
      <p class="small" id="detail">
        If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
      </p>
    </section>
  </main>
  <script src="index.js"></script>
</body>
</html>