Alert archive / Montana / Mesoscale Discussions in 2008

Mesoscale Discussion 1683

July 4, 200813 counties in Montana

The Storm Prediction Center issued this mesoscale discussion at Jul 4, 2008, 3:02 PM MDT for 13 counties in Montana. It was in force for 58 min.

The area

The outline as issued.

The facts

Issued: Jul 4, 2008, 3:02 PM MDT (21:02 UTC)
Expired: Jul 4, 2008, 4:00 PM MDT
In force: 58 min
Issued by: the Storm Prediction Center

Counties Blaine County, MT, Carbon County, MT, Fergus County, MT, Golden Valley County, MT, Judith Basin County, MT, Musselshell County, MT, Park County, MT, Petroleum County, MT, Phillips County, MT, Stillwater County, MT, Sweet Grass County, MT, Wheatland County, MT, Yellowstone County, MT

The radar

The Billings radar (KBLX), 102 km from the middle of the area, began a volume at 21:05 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 657Jul 4, 3:05 PM MDT

The nearest sounding before it

Great_falls, MT (KTFX), launched 12:00Z, 9.0 hours before the alert went out and 135 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: 32 J/kg
Mixed-layer CIN: -527 J/kg
Mixed-layer LCL: 2745 m above ground
0-6 km bulk shear: 39 kt
0-1 km storm-relative helicity: 132 m²/s²
0-3 km storm-relative helicity: 109 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

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 4, 1:45 PM MDT	Mesoscale Discussion	SPC	Beaverhead, Broadwater, Cascade, Chouteau, Deer Lodge, Flathead and 15 more	60 min
Jul 4, 2:04 PM MDT	Severe Thunderstorm Watch	SPC	Beaverhead, Broadwater, Cascade, Chouteau, Deer Lodge, Flathead and 15 more	8 hr
Jul 4, 3:05 PM MDT	Severe Thunderstorm Watch	SPC	Blaine, Fergus, Gallatin, Garfield, Golden Valley, Judith Basin and 10 more	7 hr
Jul 4, 5:45 PM MDT	Mesoscale Discussion	SPC	Beaverhead, Blaine, Broadwater, Cascade, Chouteau, Deer Lodge and 28 more	60 min

Nearby

Mesoscale Discussions in Montana, 2008 Every mesoscale discussion in 2008

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.