Alert archive / South Dakota / Mesoscale Discussions in 2005

Mesoscale Discussion 2155

September 6, 20054 states

The Storm Prediction Center issued this mesoscale discussion at Sep 6, 2005, 11:26 PM CDT for 4 states. It was in force for 3 hr.

The area

The outline as issued.

The facts

Issued: Sep 6, 2005, 11:26 PM CDT (04:26 UTC)
Expired: Sep 7, 2005, 2:00 AM CDT
In force: 3 hr
Issued by: the Storm Prediction Center

All 31 counties

Lyon County, IA, Cottonwood County, MN, Lincoln County, MN, Murray County, MN, Nobles County, MN, Pipestone County, MN, Rock County, MN, Watonwan County, MN, Boyd County, NE, Keya Paha County, NE, Aurora County, SD, Bon Homme County, SD, Brookings County, SD, Brule County, SD, Charles Mix County, SD, Davison County, SD, Douglas County, SD, Gregory County, SD, Hanson County, SD, Hutchinson County, SD, Jerauld County, SD, Lake County, SD, Lincoln County, SD, McCook County, SD, Miner County, SD, Minnehaha County, SD, Moody County, SD, Sanborn County, SD, Tripp County, SD, Turner County, SD, Yankton County, SD

The radar

The Sioux Falls radar (KFSD), 59 km from the middle of the area, began a volume at 04:30 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

Minneapolis, MN (KMPX), launched 00:00Z, 4.4 hours before the alert went out and 336 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: 1021 J/kg
Mixed-layer CIN: -49 J/kg
Mixed-layer LCL: 1052 m above ground
0-6 km bulk shear: 30 kt
0-1 km storm-relative helicity: 62 m²/s²
0-3 km storm-relative helicity: 89 m²/s²
Significant tornado parameter: 0.1
Supercell composite: 0.9

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
Sep 7, 12:43 PM CDT	Mesoscale Discussion	SPC	Allamakee, Bremer, Chickasaw, Clayton, Fayette, Winneshiek	2 hr
Sep 7, 3:03 PM CDT	Mesoscale Discussion	SPC	Banner, Box Butte, Cheyenne, Dawes, Deuel, Garden and 5 more	87 min
Sep 7, 6:40 PM CDT	Mesoscale Discussion	SPC	Banner, Box Butte, Cheyenne, Dawes, Deuel, Garden and 5 more	2 hr

Nearby

Mesoscale Discussions in South Dakota, 2005 Mesoscale Discussions in Minnesota, 2005 Mesoscale Discussions in Nebraska, 2005 Every mesoscale discussion in 2005

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.