Alert archive / South Dakota / Mesoscale Discussions in 2018

Mesoscale Discussion 448

May 17, 201823 counties in South Dakota

The Storm Prediction Center issued this mesoscale discussion at May 17, 2018, 7:11 PM MDT for 23 counties in South Dakota. It was in force for 64 min.

The area

The outline as issued.

The facts

Issued: May 17, 2018, 7:11 PM MDT (01:11 UTC)
Expired: May 17, 2018, 8:15 PM MDT
In force: 64 min
Issued by: the Storm Prediction Center

All 23 counties

Bennett County, SD, Buffalo County, SD, Dewey County, SD, Edmunds County, SD, Fall River County, SD, Faulk County, SD, Haakon County, SD, Hand County, SD, Hughes County, SD, Hyde County, SD, Jackson County, SD, Jones County, SD, Lyman County, SD, Mellette County, SD, Oglala Lakota County, SD, Pennington County, SD, Potter County, SD, Stanley County, SD, Sully County, SD, Todd County, SD, Tripp County, SD, Walworth County, SD, Ziebach County, SD

The radar

The Rapid City radar (KUDX), 139 km from the middle of the area, began a volume at 01:11 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

Aberdeen, SD (KABR), launched 00:00Z, 1.2 hours before the alert went out and 229 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: 110 J/kg
Mixed-layer CIN: -83 J/kg
Mixed-layer LCL: 2685 m above ground
0-6 km bulk shear: 36 kt
0-1 km storm-relative helicity: 74 m²/s²
0-3 km storm-relative helicity: 58 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
May 17, 6:47 PM MDT	Mesoscale Discussion	SPC	Bennett, Fall River, Oglala Lakota	58 min
May 17, 9:03 PM MDT	Mesoscale Discussion	SPC	Bennett, Hughes, Hyde, Jones, Lyman, Mellette and 4 more	117 min
May 18, 1:50 PM MDT	Mesoscale Discussion	SPC	Custer, Fall River, Lawrence	115 min
May 18, 5:04 PM MDT	Mesoscale Discussion	SPC	Custer, Fall River, Lawrence, Meade, Oglala Lakota, Pennington	86 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.