Alert archive / South Dakota / Mesoscale Discussions in 2011

Mesoscale Discussion 1696

July 22, 20115 counties in Minnesota; 8 counties in North Dakota; 16 counties in South Dakota

The Storm Prediction Center issued this mesoscale discussion at Jul 22, 2011, 5:46 PM CDT for 5 counties in Minnesota; 8 counties in North Dakota; 16 counties in South Dakota. It was in force for 89 min.

The area

The outline as issued.

The facts

Issued: Jul 22, 2011, 5:46 PM CDT (22:46 UTC)
Expired: Jul 22, 2011, 7:15 PM CDT
In force: 89 min
Issued by: the Storm Prediction Center

All 29 counties

Big Stone County, MN, Grant County, MN, Stevens County, MN, Traverse County, MN, Wilkin County, MN, Barnes County, ND, Dickey County, ND, LaMoure County, ND, Logan County, ND, McIntosh County, ND, Ransom County, ND, Richland County, ND, Sargent County, ND, Brown County, SD, Campbell County, SD, Clark County, SD, Codington County, SD, Day County, SD, Deuel County, SD, Edmunds County, SD, Faulk County, SD, Grant County, SD, Hamlin County, SD, Marshall County, SD, McPherson County, SD, Potter County, SD, Roberts County, SD, Spink County, SD, Walworth County, SD

The radar

The Aberdeen radar (KABR), 33 km from the middle of the area, began a volume at 22:50 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.

Tornado Watch 674Jul 22, 6:15 PM CDT

The nearest sounding before it

Aberdeen, SD (KABR), launched 12:00Z, 10.8 hours before the alert went out and 91 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: 593 J/kg
Mixed-layer CIN: -243 J/kg
Mixed-layer LCL: 2003 m above ground
0-6 km bulk shear: 45 kt
0-1 km storm-relative helicity: 67 m²/s²
0-3 km storm-relative helicity: 58 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.3

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
Jul 22, 3:00 PM CDT	Mesoscale Discussion	SPC	Blue Earth, Brown, Carver, Chippewa, Cottonwood, Dakota and 32 more	90 min
Jul 22, 6:14 PM CDT	Tornado Watch	SPC	Big Stone, Traverse, Wilkin	8 hr
Jul 22, 11:05 AM CDT	Mesoscale Discussion	SPC	Adams, Billings, Bowman, Dunn, Golden Valley, Grant and 8 more	55 min
Jul 22, 5:17 PM CDT	Mesoscale Discussion	SPC	Adams, Billings, Bowman, Dunn, Golden Valley, Grant and 8 more	88 min
Jul 22, 5:35 PM CDT	Tornado Watch	SPC	Adams, Billings, Bowman, Burke, Burleigh, Divide and 21 more	8 hr
Jul 21, 7:10 PM CDT	Mesoscale Discussion	SPC	Bennett, Jackson, Jones, Lyman, Mellette, Todd and 1 more	95 min
Jul 22, 6:22 PM CDT	Mesoscale Discussion	SPC	Brule, Buffalo, Gregory, Lyman, Mellette, Todd and 1 more	53 min

Nearby

Mesoscale Discussions in South Dakota, 2011 Mesoscale Discussions in North Dakota, 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.