Alert archive / South Dakota / Mesoscale Discussions in 2013

Mesoscale Discussion 407

April 9, 2013Lincoln County, Lyon County, Pipestone County, Minnesota; 14 counties in South Dakota

The Storm Prediction Center issued this mesoscale discussion at Apr 9, 2013, 4:22 AM CDT for Lincoln County, Lyon County, Pipestone County, Minnesota; 14 counties in South Dakota. It was in force for 5 hr.

The area

The outline as issued.

The facts

Issued: Apr 9, 2013, 4:22 AM CDT (09:22 UTC)
Expired: Apr 9, 2013, 9:15 AM CDT
In force: 5 hr
Issued by: the Storm Prediction Center

Counties Lincoln County, MN, Lyon County, MN, Pipestone County, MN, Aurora County, SD, Brookings County, SD, Charles Mix County, SD, Davison County, SD, Douglas County, SD, Hanson County, SD, Hutchinson County, SD, Kingsbury County, SD, Lake County, SD, McCook County, SD, Miner County, SD, Minnehaha County, SD, Moody County, SD, Sanborn County, SD

The radar

The Sioux Falls radar (KFSD), 51 km from the middle of the area, began a volume at 09:25 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

Omaha, NE (KOAX), launched 00:00Z, 9.4 hours before the alert went out and 288 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: 870 J/kg
Mixed-layer CIN: -77 J/kg
Mixed-layer LCL: 880 m above ground
0-6 km bulk shear: 38 kt
0-1 km storm-relative helicity: 44 m²/s²
0-3 km storm-relative helicity: 63 m²/s²
Significant tornado parameter: 0.2
Supercell composite: 0.7

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
Apr 9, 6:46 PM CDT	Mesoscale Discussion	SPC	Aurora, Bennett, Brule, Buffalo, Charles Mix, Custer and 18 more	5 hr

Nearby

Mesoscale Discussions in South Dakota, 2013 Mesoscale Discussions in Minnesota, 2013 Every mesoscale discussion in 2013

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.