Alert archive / Montana / Severe Thunderstorm Warnings in 2018

Severe Thunderstorm Warning 30, NWS Glasgow, MT

May 30, 2018Garfield County, Petroleum County, Montana

NWS Glasgow, MT issued this severe thunderstorm warning at May 30, 2018, 7:52 PM MDT for Garfield County, Petroleum County, Montana. It was in force for 53 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued: May 30, 2018, 7:52 PM MDT (01:52 UTC)
Expired: May 30, 2018, 8:45 PM MDT
In force: 53 min
Issued by: NWS Glasgow, MT
Area: Storm-based polygon
Hail: 1.25 in
Wind: 60.0 mph

Counties Garfield County, MT, Petroleum County, MT

The radar

The Glasgow radar (KGGW), 135 km from the middle of the area, began a volume at 01:55 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

Glasgow Intl Airport, MT (KGGW), launched 00:00Z, 1.9 hours before the alert went out and 137 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: 145 J/kg
Mixed-layer CIN: -95 J/kg
Mixed-layer LCL: 2003 m above ground
0-6 km bulk shear: 38 kt
0-1 km storm-relative helicity: -107 m²/s²
0-3 km storm-relative helicity: -37 m²/s²
Significant tornado parameter: 0.0
Supercell composite: -0.2

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this severe thunderstorm warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Glasgow, MT wrote its last area forecast discussion before this severe thunderstorm warning went out at May 30, 6:32 PM MDT, 1 hour 20 minutes earlier.

Area forecast discussion, May 30, 6:32 PM MDT, 1 hour 20 minutes before

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In the hours before

Special weather statement, May 30, 7:39 PM MDT, 13 minutes before

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  <meta charset="utf-8">
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  <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>
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      <p id="message1">
        The site you requested is temporarily down for maintenance or an unexpected outage.
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      <p id="message2">
        Please try again in a few minutes.
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The office that day

Everything else NWS Glasgow, MT issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
May 30, 7:25 PM MDT	Areal Flood Advisory	GGW	Phillips	3 hr
May 30, 7:39 PM MDT	Special Weather Statement	GGW	Petroleum	66 min
May 30, 9:15 PM MDT	Special Weather Statement	GGW	Valley	60 min
May 30, 10:06 PM MDT	Special Weather Statement	GGW	Garfield	54 min
May 30, 10:08 PM MDT	Severe Thunderstorm Warning	GGW	Valley	52 min
May 30, 10:35 PM MDT	Special Weather Statement	GGW	Richland	40 min
May 30, 11:00 PM MDT	Special Weather Statement	GGW	Roosevelt	60 min
May 30, 11:07 PM MDT	Severe Thunderstorm Warning	GGW	Richland	38 min
May 31, 12:53 AM MDT	Special Weather Statement	GGW	Richland	52 min

Nearby

Severe Thunderstorm Warnings in Montana, 2018 Every severe thunderstorm warning in 2018

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.