Alert archive / Maine / Mesoscale Discussions in 2011

Mesoscale Discussion 1674

July 21, 20114 counties in Maine; Coos County, New Hampshire; 4 counties in Vermont

The Storm Prediction Center issued this mesoscale discussion at Jul 21, 2011, 12:14 PM EDT for 4 counties in Maine; Coos County, New Hampshire; 4 counties in Vermont. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued: Jul 21, 2011, 12:14 PM EDT (16:14 UTC)
Expired: Jul 21, 2011, 2:15 PM EDT
In force: 2 hr
Issued by: the Storm Prediction Center

Counties Franklin County, ME, Oxford County, ME, Piscataquis County, ME, Somerset County, ME, Coos County, NH, Caledonia County, VT, Essex County, VT, Lamoille County, VT, Orleans County, VT

The radar

The Portland,ME radar (KGYX), 158 km from the middle of the area, began a volume at 16:15 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 667Jul 21, 12:35 PM EDT

The nearest sounding before it

Caribou, ME (KCAR), launched 12:00Z, 4.2 hours before the alert went out and 263 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: 318 J/kg
Mixed-layer CIN: -35 J/kg
Mixed-layer LCL: 601 m above ground
0-6 km bulk shear: 47 kt
0-1 km storm-relative helicity: 82 m²/s²
0-3 km storm-relative helicity: 139 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.9

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
Jul 20, 9:09 PM EDT	Mesoscale Discussion	SPC	Aroostook, Penobscot, Piscataquis, Somerset	96 min
Jul 21, 12:36 PM EDT	Severe Thunderstorm Watch	SPC	Aroostook, Franklin, Hancock, Penobscot, Piscataquis, Somerset and 1 more	5 hr
Jul 21, 3:17 PM EDT	Mesoscale Discussion	SPC	Androscoggin, Cumberland, Oxford	58 min
Jul 21, 4:33 PM EDT	Mesoscale Discussion	SPC	Franklin, Penobscot, Piscataquis, Somerset, Washington	57 min

Nearby

Mesoscale Discussions in Maine, 2011 Mesoscale Discussions in Vermont, 2011 Mesoscale Discussions in New Hampshire, 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.