Alert archive / Florida / Mesoscale Discussions in 2014

Mesoscale Discussion 1986

December 23, 201413 counties in Florida

The Storm Prediction Center issued this mesoscale discussion at Dec 23, 2014, 12:12 PM CST for 13 counties in Florida. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued: Dec 23, 2014, 12:12 PM CST (18:12 UTC)
Expired: Dec 23, 2014, 2:15 PM CST
In force: 2 hr
Issued by: the Storm Prediction Center
Chance of a watch: 40%

Counties Bay County, FL, Calhoun County, FL, Franklin County, FL, Gadsden County, FL, Gulf County, FL, Holmes County, FL, Jackson County, FL, Jefferson County, FL, Leon County, FL, Liberty County, FL, Taylor County, FL, Wakulla County, FL, Washington County, FL

The radar

The Tallahassee radar (KTLH), 45 km from the middle of the area, began a volume at 18:13 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 watches that followed

Watches SPC issued over any of the same counties within four hours of this discussion.

Tornado Watch 561Dec 23, 2:45 PM CST

The nearest sounding before it

Tallahassee Rgnl, FL (KTLH), launched 12:00Z, 6.2 hours before the alert went out and 47 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: 322 J/kg
Mixed-layer CIN: -93 J/kg
Mixed-layer LCL: 604 m above ground
0-6 km bulk shear: 48 kt
0-1 km storm-relative helicity: 360 m²/s²
0-3 km storm-relative helicity: 424 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 6.2

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

<!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>

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Dec 23, 3:45 AM CST	Mesoscale Discussion	SPC	Bay, Escambia, Gulf, Okaloosa, Santa Rosa, Walton	2 hr
Dec 23, 7:40 AM CST	Mesoscale Discussion	SPC	Bay, Calhoun, Escambia, Franklin, Gadsden, Gulf and 8 more	2 hr
Dec 23, 2:06 PM CST	Mesoscale Discussion	SPC	Escambia, Holmes, Okaloosa, Santa Rosa, Walton, Washington	114 min
Dec 23, 2:47 PM CST	Tornado Watch	SPC	Bay, Calhoun, Dixie, Escambia, Franklin, Gadsden and 14 more	8 hr

Nearby

Mesoscale Discussions in Florida, 2014 Every mesoscale discussion in 2014

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.