Alert archive / Montana / Severe Thunderstorm Warnings in 2011

Severe Thunderstorm Warning 166, NWS Glasgow, MT

August 31, 2011Daniels County, Roosevelt County, Sheridan County, Montana

NWS Glasgow, MT issued this severe thunderstorm warning at Aug 31, 2011, 6:50 PM MDT for Daniels County, Roosevelt County, Sheridan County, Montana. It was in force for 55 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: Aug 31, 2011, 6:50 PM MDT (00:50 UTC)
Expired: Aug 31, 2011, 7:45 PM MDT
In force: 55 min
Issued by: NWS Glasgow, MT
Area: Storm-based polygon

Counties Daniels County, MT, Roosevelt County, MT, Sheridan County, MT

The radar

The Glasgow radar (KGGW), 126 km from the middle of the area, began a volume at 00:53 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, 0.8 hours before the alert went out and 124 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: 1322 J/kg
Mixed-layer CIN: -21 J/kg
Mixed-layer LCL: 1754 m above ground
0-6 km bulk shear: 54 kt
0-1 km storm-relative helicity: 70 m²/s²
0-3 km storm-relative helicity: 186 m²/s²
Significant tornado parameter: 0.4
Supercell composite: 6.8

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 Aug 31, 3:20 PM MDT, 3 hours 30 minutes earlier.

Area forecast discussion, Aug 31, 3:20 PM MDT, 3 hours 30 minutes before

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Hazardous weather outlook, Aug 31, 2:35 PM MDT, 4 hours 15 minutes before

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      <div class="status" id="status">Temporary Notice</div>
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        The site you requested is temporarily down for maintenance or an unexpected outage.
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The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 31, 6:22 PM MDT	Severe Thunderstorm Warning	GGW	Valley	53 min
Aug 31, 6:38 PM MDT	Severe Thunderstorm Warning	GGW	Valley	53 min
Aug 31, 6:53 PM MDT	Severe Thunderstorm Warning	GGW	Garfield, McCone, Valley	67 min
Aug 31, 7:08 PM MDT	Severe Thunderstorm Warning	GGW	Dawson, Richland, Roosevelt, Wibaux	52 min
Aug 31, 7:15 PM MDT	Severe Thunderstorm Warning	GGW	Daniels, Roosevelt, Valley	60 min
Aug 31, 7:24 PM MDT	Severe Thunderstorm Warning	GGW	Dawson, McCone, Richland, Roosevelt	66 min
Aug 31, 7:39 PM MDT	Severe Thunderstorm Warning	GGW	Daniels, Roosevelt, Sheridan	81 min
Aug 31, 7:58 PM MDT	Severe Thunderstorm Warning	GGW	Dawson, Richland, Roosevelt, Wibaux	47 min
Aug 31, 9:05 PM MDT	Severe Thunderstorm Warning	GGW	Dawson, Prairie, Richland, Wibaux	55 min
Aug 31, 9:10 PM MDT	Special Weather Statement	GGW	Sheridan	35 min
Sep 1, 2:38 PM MDT	Lake Wind Advisory	GGW	Garfield, McCone, Petroleum, Phillips, Valley	37 hr

Nearby

Severe Thunderstorm Warnings in Montana, 2011 Every severe thunderstorm warning 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.