Alert archive / South Dakota / Mesoscale Discussions in 2013

Mesoscale Discussion 1664

August 7, 20135 counties in Nebraska; 12 counties in South Dakota; Campbell County, Crook County, Weston County, Wyoming

The Storm Prediction Center issued this mesoscale discussion at Aug 7, 2013, 10:05 PM MDT for 5 counties in Nebraska; 12 counties in South Dakota; Campbell County, Crook County, Weston County, Wyoming. It was in force for 55 min.

The area

The outline as issued.

The facts

Issued: Aug 7, 2013, 10:05 PM MDT (04:05 UTC)
Expired: Aug 7, 2013, 11:00 PM MDT
In force: 55 min
Issued by: the Storm Prediction Center

Counties Box Butte County, NE, Cherry County, NE, Dawes County, NE, Sheridan County, NE, Sioux County, NE, Bennett County, SD, Butte County, SD, Custer County, SD, Fall River County, SD, Jackson County, SD, Lawrence County, SD, Meade County, SD, Mellette County, SD, Oglala Lakota County, SD, Pennington County, SD, Todd County, SD, Tripp County, SD, Campbell County, WY, Crook County, WY, Weston County, WY

The radar

The Rapid City radar (KUDX), 46 km from the middle of the area, began a volume at 04:07 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

Rapid City, SD (KRAP), launched 00:00Z, 4.1 hours before the alert went out and 41 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: 51 J/kg
Mixed-layer CIN: -115 J/kg
Mixed-layer LCL: 2150 m above ground
0-6 km bulk shear: 46 kt
0-1 km storm-relative helicity: -2 m²/s²
0-3 km storm-relative helicity: 278 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 7, 6:49 PM MDT	Mesoscale Discussion	SPC	Box Butte, Cherry, Dawes, Sheridan, Sioux	86 min

Nearby

Mesoscale Discussions in South Dakota, 2013 Mesoscale Discussions in Nebraska, 2013 Mesoscale Discussions in Wyoming, 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.