Alert archive / South Dakota / Mesoscale Discussions in 2011

Mesoscale Discussion 2074

August 28, 2011Pipestone County, Rock County, Minnesota; Boyd County, Keya Paha County, Knox County, Nebraska; 39 counties in South Dakota

The Storm Prediction Center issued this mesoscale discussion at Aug 28, 2011, 5:16 AM CDT for Pipestone County, Rock County, Minnesota; Boyd County, Keya Paha County, Knox County, Nebraska; 39 counties in South Dakota. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued: Aug 28, 2011, 5:16 AM CDT (10:16 UTC)
Expired: Aug 28, 2011, 7:45 AM CDT
In force: 2 hr
Issued by: the Storm Prediction Center

All 44 counties

Pipestone County, MN, Rock County, MN, Boyd County, NE, Keya Paha County, NE, Knox County, NE, Aurora County, SD, Beadle County, SD, Bon Homme County, SD, Brookings County, SD, Brule County, SD, Buffalo County, SD, Campbell County, SD, Charles Mix County, SD, Clark County, SD, Clay County, SD, Davison County, SD, Douglas County, SD, Edmunds County, SD, Faulk County, SD, Gregory County, SD, Hamlin County, SD, Hand County, SD, Hanson County, SD, Hughes County, SD, Hutchinson County, SD, Hyde County, SD, Jerauld County, SD, Kingsbury County, SD, Lake County, SD, Lincoln County, SD, Lyman County, SD, McCook County, SD, McPherson County, SD, Miner County, SD, Minnehaha County, SD, Moody County, SD, Potter County, SD, Sanborn County, SD, Spink County, SD, Sully County, SD, Tripp County, SD, Turner County, SD, Walworth County, SD, Yankton County, SD

The radar

The Aberdeen radar (KABR), 105 km from the middle of the area, began a volume at 10:18 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 814Aug 28, 8:00 AM CDT

The nearest sounding before it

Aberdeen, SD (KABR), launched 00:00Z, 10.3 hours before the alert went out and 48 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: 2184 m above ground
0-6 km bulk shear: 51 kt
0-1 km storm-relative helicity: 13 m²/s²
0-3 km storm-relative helicity: 341 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.2

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

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SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Aug 28, 8:00 AM CDT	Severe Thunderstorm Watch	SPC	Murray, Nobles, Pipestone, Rock	5 hr
Aug 28, 10:41 AM CDT	Mesoscale Discussion	SPC	Antelope, Burt, Butler, Cass, Cedar, Colfax and 17 more	94 min
Aug 28, 2:09 AM CDT	Mesoscale Discussion	SPC	Brown, Campbell, Corson, Dewey, Edmunds, Faulk and 5 more	66 min

Nearby

Mesoscale Discussions in South Dakota, 2011 Mesoscale Discussions in Nebraska, 2011 Mesoscale Discussions in Minnesota, 2011 Every mesoscale discussion 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.