Alert archive / Michigan / Mesoscale Discussions in 2011

Mesoscale Discussion 2104

September 3, 201111 counties in Michigan

The Storm Prediction Center issued this mesoscale discussion at Sep 3, 2011, 6:53 AM EDT for 11 counties in Michigan. It was in force for 97 min.

The area

The outline as issued.

The facts

Issued: Sep 3, 2011, 6:53 AM EDT (10:53 UTC)
Expired: Sep 3, 2011, 8:30 AM EDT
In force: 97 min
Issued by: the Storm Prediction Center

Counties Clinton County, MI, Genesee County, MI, Gratiot County, MI, Ionia County, MI, Isabella County, MI, Kent County, MI, Mecosta County, MI, Montcalm County, MI, Newaygo County, MI, Saginaw County, MI, Shiawassee County, MI

The radar

The Grand Rapids radar (KGRR), 62 km from the middle of the area, began a volume at 10:56 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.

Severe Thunderstorm Watch 827Sep 3, 7:20 AM EDT

The nearest sounding before it

Green Bay/Straub, WI (KGRB), launched 00:00Z, 10.9 hours before the alert went out and 291 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: 1502 J/kg
Mixed-layer CIN: -41 J/kg
Mixed-layer LCL: 742 m above ground
0-6 km bulk shear: 45 kt
0-1 km storm-relative helicity: 40 m²/s²
0-3 km storm-relative helicity: 90 m²/s²
Significant tornado parameter: 0.3
Supercell composite: 1.6

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
Sep 3, 7:22 AM EDT	Severe Thunderstorm Watch	SPC	Allegan, Barry, Bay, Clinton, Eaton, Genesee and 19 more	5 hr
Sep 3, 10:45 AM EDT	Mesoscale Discussion	SPC	Arenac, Bay, Huron, Sanilac, Tuscola	60 min
Sep 3, 1:24 PM EDT	Mesoscale Discussion	SPC	Allegan, Berrien, Cass, Kalamazoo, Saint Joseph, Van Buren	66 min
Sep 3, 4:05 PM EDT	Severe Thunderstorm Watch	SPC	Berrien, Branch, Calhoun, Cass, Eaton, Genesee and 17 more	7 hr
Sep 3, 6:02 PM EDT	Mesoscale Discussion	SPC	Berrien, Branch, Calhoun, Cass, Eaton, Genesee and 16 more	58 min

Nearby

Mesoscale Discussions in Michigan, 2011 Every mesoscale discussion in 2011

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.