Alert archive / Montana / Mesoscale Discussions in 2007

Mesoscale Discussion 838

May 19, 200715 counties in Montana

The Storm Prediction Center issued this mesoscale discussion at May 19, 2007, 5:43 PM MDT for 15 counties in Montana. It was in force for 92 min.

The area

The outline as issued.

The facts

Issued: May 19, 2007, 5:43 PM MDT (23:43 UTC)
Expired: May 19, 2007, 7:15 PM MDT
In force: 92 min
Issued by: the Storm Prediction Center

Counties Big Horn County, MT, Carter County, MT, Custer County, MT, Fergus County, MT, Golden Valley County, MT, Judith Basin County, MT, Musselshell County, MT, Petroleum County, MT, Powder River County, MT, Rosebud County, MT, Stillwater County, MT, Sweet Grass County, MT, Treasure County, MT, Wheatland County, MT, Yellowstone County, MT

The radar

The Billings radar (KBLX), 92 km from the middle of the area, began a volume at 23:45 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

Great_falls, MT (KTFX), launched 12:00Z, 11.7 hours before the alert went out and 293 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 1650 m above ground
0-6 km bulk shear: 31 kt
0-1 km storm-relative helicity: 74 m²/s²
0-3 km storm-relative helicity: 123 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
May 19, 1:41 PM MDT	Mesoscale Discussion	SPC	Big Horn, Broadwater, Carbon, Cascade, Fergus, Golden Valley and 12 more	64 min
May 19, 2:36 PM MDT	Severe Thunderstorm Watch	SPC	Big Horn, Broadwater, Carbon, Carter, Cascade, Chouteau and 18 more	7 hr

Nearby

Mesoscale Discussions in Montana, 2007 Every mesoscale discussion in 2007

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.