Alert archive / South Dakota / Mesoscale Discussions in 2019

Mesoscale Discussion 657

May 17, 20194 counties in Nebraska; 20 counties in South Dakota

The Storm Prediction Center issued this mesoscale discussion at May 17, 2019, 7:53 PM CDT for 4 counties in Nebraska; 20 counties in South Dakota. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued: May 17, 2019, 7:53 PM CDT (00:53 UTC)
Expired: May 17, 2019, 10:00 PM CDT
In force: 2 hr
Issued by: the Storm Prediction Center

All 24 counties

Boyd County, NE, Cherry County, NE, Keya Paha County, NE, Sheridan County, NE, Aurora County, SD, Beadle County, SD, Bennett County, SD, Bon Homme County, SD, Brule County, SD, Buffalo County, SD, Charles Mix County, SD, Davison County, SD, Douglas County, SD, Gregory County, SD, Hanson County, SD, Hutchinson County, SD, Jackson County, SD, Jerauld County, SD, Jones County, SD, Lyman County, SD, Mellette County, SD, Sanborn County, SD, Todd County, SD, Tripp County, SD

The radar

The North Platte radar (KLNX), 176 km from the middle of the area, began a volume at 00:52 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, 0.9 hours before the alert went out and 195 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: 1904 m above ground
0-6 km bulk shear: 51 kt
0-1 km storm-relative helicity: 408 m²/s²
0-3 km storm-relative helicity: 683 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, 8:12 PM CDT	Mesoscale Discussion	SPC	Antelope, Boone, Custer, Dawson, Garfield, Greeley and 5 more	2 hr
May 17, 11:14 PM CDT	Mesoscale Discussion	SPC	Adams, Antelope, Boone, Buffalo, Butler, Cass and 48 more	2 hr
May 17, 11:45 PM CDT	Severe Thunderstorm Watch	SPC	Cass, Gage, Jefferson, Johnson, Lancaster, Nemaha and 4 more	3 hr

Nearby

Mesoscale Discussions in South Dakota, 2019 Mesoscale Discussions in Nebraska, 2019 Every mesoscale discussion in 2019

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.