Alert archive / Florida / Severe Thunderstorm Warnings in 2017

Severe Thunderstorm Warning 298, NWS Jacksonville, FL

November 23, 2017Marion County, Florida

NWS Jacksonville, FL issued this severe thunderstorm warning at Nov 23, 2017, 7:33 AM EST for Marion County, Florida. It was in force for 27 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued: Nov 23, 2017, 7:33 AM EST (12:33 UTC)
Expired: Nov 23, 2017, 8:00 AM EST
In force: 27 min
Issued by: NWS Jacksonville, FL
Area: Storm-based polygon
Hail: 0.88 in
Wind: 60.0 mph

County Marion County, FL

The radar

The Jacksonville radar (KJAX), 146 km from the middle of the area, began a volume at 12:34 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

The nearest sounding before it

Cape Canaveral, FL (KXMR), launched 12:00Z, 0.6 hours before the alert went out and 173 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.

Mixed-layer CAPE: 339 J/kg
Mixed-layer CIN: -21 J/kg
Mixed-layer LCL: 937 m above ground
0-6 km bulk shear: 50 kt
0-1 km storm-relative helicity: 63 m²/s²
0-3 km storm-relative helicity: 200 m²/s²
Significant tornado parameter: 0.1
Supercell composite: 1.0

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this severe thunderstorm warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Jacksonville, FL wrote its last area forecast discussion before this severe thunderstorm warning went out at Nov 23, 4:35 AM EST, 2 hours 58 minutes earlier.

Area forecast discussion, Nov 23, 4:35 AM EST, 2 hours 58 minutes before

<!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>

Hazardous weather outlook, Nov 23, 5:01 AM EST, 2 hours 32 minutes before

<!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>

In the hours before

Special weather statement, Nov 23, 6:12 AM EST, 1 hour 21 minutes before

<!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>

Special weather statement, Nov 23, 7:02 AM EST, 31 minutes before

<!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>

The office that day

Everything else NWS Jacksonville, FL issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Nov 23, 3:08 AM EST	Small Craft Advisory	JAX		47 hr
Nov 23, 6:12 AM EST	Special Weather Statement	JAX	Marion	33 min
Nov 23, 6:22 AM EST	Severe Thunderstorm Warning	JAX	Marion	38 min
Nov 23, 7:02 AM EST	Special Weather Statement	JAX	Marion	43 min
Nov 23, 7:05 AM EST	Areal Flood Advisory	JAX	Alachua, Gilchrist	3 hr
Nov 23, 8:06 AM EST	Areal Flood Advisory	JAX	Marion	3 hr
Nov 23, 8:42 AM EST	Areal Flood Warning	JAX	Marion	3 hr
Nov 23, 11:01 AM EST	Areal Flood Warning	JAX	Marion	3 hr
Nov 23, 11:29 AM EST	Special Marine Warning	JAX		61 min
Nov 23, 12:25 PM EST	Special Marine Warning	JAX		65 min

Nearby

Severe Thunderstorm Warnings in Florida, 2017 Every severe thunderstorm warning in 2017

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.