Alert archive / South Dakota / Mesoscale Discussions in 2020

Mesoscale Discussion 856

June 6, 202018 counties in Nebraska; Adams County, Bowman County, North Dakota; 19 counties in South Dakota

The Storm Prediction Center issued this mesoscale discussion at Jun 6, 2020, 2:33 PM MDT for 18 counties in Nebraska; Adams County, Bowman County, North Dakota; 19 counties in South Dakota. It was in force for 117 min.

The area

The outline as issued.

The facts

Issued: Jun 6, 2020, 2:33 PM MDT (20:33 UTC)
Expired: Jun 6, 2020, 4:30 PM MDT
In force: 117 min
Issued by: the Storm Prediction Center
Concerning: Severe potential...watch likely
Chance of a watch: 80%

All 39 counties

Adams County, ND, Bowman County, ND, Arthur County, NE, Box Butte County, NE, Cherry County, NE, Cheyenne County, NE, Dawes County, NE, Deuel County, NE, Garden County, NE, Grant County, NE, Hooker County, NE, Keith County, NE, Lincoln County, NE, Logan County, NE, McPherson County, NE, Morrill County, NE, Scotts Bluff County, NE, Sheridan County, NE, Sioux County, NE, Thomas County, NE, Bennett County, SD, Butte County, SD, Corson County, SD, Custer County, SD, Dewey County, SD, Fall River County, SD, Haakon County, SD, Harding County, SD, Jackson County, SD, Jones County, SD, Lawrence County, SD, Meade County, SD, Mellette County, SD, Oglala Lakota County, SD, Pennington County, SD, Perkins County, SD, Stanley County, SD, Todd County, SD, Ziebach County, SD

The radar

The Rapid City radar (KUDX), 85 km from the middle of the area, began a volume at 20:37 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 264Jun 6, 4:45 PM MDT

The nearest sounding before it

Rapid City, SD (KUNR), launched 12:00Z, 8.6 hours before the alert went out and 81 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: 39 J/kg
Mixed-layer CIN: -739 J/kg
Mixed-layer LCL: 1598 m above ground
0-6 km bulk shear: 13 kt
0-1 km storm-relative helicity: -52 m²/s²
0-3 km storm-relative helicity: -15 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.1

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
Jun 5, 7:01 PM MDT	Mesoscale Discussion	SPC	Banner, Box Butte, Cheyenne, Dawes, Morrill, Scotts Bluff and 2 more	119 min
Jun 6, 1:23 PM MDT	Severe Thunderstorm Watch	SPC	Banner, Box Butte, Cheyenne, Dawes, Kimball, Morrill and 2 more	7 hr
Jun 6, 4:49 PM MDT	Severe Thunderstorm Watch	SPC	Arthur, Blaine, Brown, Chase, Cherry, Deuel and 12 more	6 hr
Jun 6, 5:25 PM MDT	Mesoscale Discussion	SPC	Box Butte, Dawes, Morrill, Scotts Bluff, Sheridan, Sioux	95 min

Nearby

Mesoscale Discussions in South Dakota, 2020 Mesoscale Discussions in Nebraska, 2020 Mesoscale Discussions in North Dakota, 2020 Every mesoscale discussion in 2020

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.