Alert archive / South Dakota / Severe Thunderstorm Warnings in 2011

Severe Thunderstorm Warning 2, NWS Rapid City, SD

May 8, 2011Tripp County, South Dakota

NWS Rapid City, SD issued this severe thunderstorm warning at May 8, 2011, 8:20 PM CDT for Tripp County, South Dakota. It was in force for 45 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 8, 2011, 8:20 PM CDT (01:20 UTC)
Expired: May 8, 2011, 9:05 PM CDT
In force: 45 min
Issued by: NWS Rapid City, SD
Area: Storm-based polygon
Hail: 1.0 in
Wind: 50.0 mph

County Tripp County, SD

The radar

The North Platte radar (KLNX), 164 km from the middle of the area, began a volume at 01:22 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 watch it was issued in

The SPC watch in force over the same counties when this warning went out.

Issued	Product	Office	Lasted
May 8, 6:13 PM CDT	Tornado Watch	SPC	6 hr

The nearest sounding before it

Aberdeen, SD (KABR), launched 00:00Z, 1.3 hours before the alert went out and 209 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: 1839 m above ground
0-6 km bulk shear: 39 kt
0-1 km storm-relative helicity: 156 m²/s²
0-3 km storm-relative helicity: 413 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 3.1

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 Rapid City, SD wrote its last area forecast discussion before this severe thunderstorm warning went out at May 8, 6:35 PM CDT, 1 hour 45 minutes earlier.

Area forecast discussion, May 8, 6:35 PM CDT, 1 hour 45 minutes before

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Hazardous weather outlook, May 8, 5:17 AM CDT, 15 hours 3 minutes before

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The office that day

Everything else NWS Rapid City, SD issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
May 9, 6:42 PM CDT	Severe Thunderstorm Warning	UNR	Weston	63 min
May 9, 6:53 PM CDT	Flash Flood Warning	UNR	Weston	5 hr

Nearby

Severe Thunderstorm Warnings in South Dakota, 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.