Alert archive / South Dakota / Mesoscale Discussions in 2018

Mesoscale Discussion 1347

August 23, 201812 counties in South Dakota

The Storm Prediction Center issued this mesoscale discussion at Aug 23, 2018, 4:32 PM CDT for 12 counties in South Dakota. It was in force for 118 min.

The area

The outline as issued.

The facts

Issued: Aug 23, 2018, 4:32 PM CDT (21:32 UTC)
Expired: Aug 23, 2018, 6:30 PM CDT
In force: 118 min
Issued by: the Storm Prediction Center
Chance of a watch: 40%

Counties Brule County, SD, Buffalo County, SD, Edmunds County, SD, Faulk County, SD, Hand County, SD, Hughes County, SD, Hyde County, SD, Lyman County, SD, Potter County, SD, Sully County, SD, Tripp County, SD, Walworth County, SD

The radar

The Aberdeen radar (KABR), 151 km from the middle of the area, began a volume at 21:36 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.

The nearest sounding before it

Aberdeen, SD (KABR), launched 12:00Z, 9.5 hours before the alert went out and 112 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 895 m above ground
0-6 km bulk shear: 25 kt
0-1 km storm-relative helicity: 96 m²/s²
0-3 km storm-relative helicity: 223 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

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SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Aug 23, 3:32 PM CDT	Mesoscale Discussion	SPC	Butte, Custer, Fall River, Lawrence, Meade, Oglala Lakota and 1 more	118 min
Aug 23, 6:01 PM CDT	Severe Thunderstorm Watch	SPC	Brown, Campbell, Day, Edmunds, Faulk, Hand and 7 more	6 hr
Aug 23, 6:25 PM CDT	Severe Thunderstorm Watch	SPC	Aurora, Brule, Buffalo, Charles Mix, Douglas, Gregory and 6 more	3 hr
Aug 23, 6:47 PM CDT	Mesoscale Discussion	SPC	Aurora, Brule, Buffalo, Charles Mix, Douglas, Gregory and 6 more	88 min

Nearby

Mesoscale Discussions in South Dakota, 2018 Every mesoscale discussion in 2018

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.