Alert archive / South Dakota / Mesoscale Discussions in 2008

Mesoscale Discussion 2071

August 11, 2008Emmons County, Logan County, McIntosh County, North Dakota; 17 counties in South Dakota

The Storm Prediction Center issued this mesoscale discussion at Aug 11, 2008, 1:56 PM CDT for Emmons County, Logan County, McIntosh County, North Dakota; 17 counties in South Dakota. It was in force for 94 min.

The area

The outline as issued.

The facts

Issued: Aug 11, 2008, 1:56 PM CDT (18:56 UTC)
Expired: Aug 11, 2008, 3:30 PM CDT
In force: 94 min
Issued by: the Storm Prediction Center

Counties Emmons County, ND, Logan County, ND, McIntosh County, ND, Brule County, SD, Buffalo County, SD, Campbell County, SD, Edmunds County, SD, Faulk County, SD, Hand County, SD, Hughes County, SD, Hyde County, SD, Jones County, SD, Lyman County, SD, McPherson County, SD, Mellette County, SD, Potter County, SD, Sully County, SD, Todd County, SD, Tripp County, SD, Walworth County, SD

The radar

The Aberdeen radar (KABR), 160 km from the middle of the area, began a volume at 18:57 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 821Aug 11, 3:00 PM CDT

The nearest sounding before it

Aberdeen, SD (KABR), launched 12:00Z, 6.9 hours before the alert went out and 134 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: 161 J/kg
Mixed-layer CIN: -85 J/kg
Mixed-layer LCL: 684 m above ground
0-6 km bulk shear: 6 kt
0-1 km storm-relative helicity: -47 m²/s²
0-3 km storm-relative helicity: -42 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

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 11, 2:58 PM CDT	Severe Thunderstorm Watch	SPC	Aurora, Beadle, Bennett, Brown, Brule, Buffalo and 28 more	7 hr
Aug 11, 5:04 PM CDT	Mesoscale Discussion	SPC	Aurora, Beadle, Brule, Buffalo, Clark, Davison and 7 more	56 min

Nearby

Mesoscale Discussions in South Dakota, 2008 Mesoscale Discussions in North Dakota, 2008 Every mesoscale discussion in 2008

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.