Alert archive / South Dakota / Mesoscale Discussions in 2020

Mesoscale Discussion 817

June 4, 20205 states

The Storm Prediction Center issued this mesoscale discussion at Jun 4, 2020, 1:25 PM MDT for 5 states. It was in force for 95 min.

The area

The outline as issued.

The facts

Issued: Jun 4, 2020, 1:25 PM MDT (19:25 UTC)
Expired: Jun 4, 2020, 3:00 PM MDT
In force: 95 min
Issued by: the Storm Prediction Center
Concerning: Severe potential...watch likely
Chance of a watch: 95%

All 33 counties

Carter County, MT, Powder River County, MT, Bowman County, ND, Boyd County, NE, Brown County, NE, Cherry County, NE, Keya Paha County, NE, Rock County, NE, Bennett County, SD, Brule County, SD, Buffalo County, SD, Butte County, SD, Custer County, SD, Gregory County, SD, Haakon County, SD, Harding County, SD, Hughes County, SD, Jackson County, SD, Jones County, SD, Lawrence County, SD, Lyman County, SD, Meade County, SD, Mellette County, SD, Oglala Lakota County, SD, Pennington County, SD, Perkins County, SD, Stanley County, SD, Todd County, SD, Tripp County, SD, Ziebach 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 19:25 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 252Jun 4, 2:25 PM MDT

The nearest sounding before it

Rapid City, SD (KUNR), launched 12:00Z, 7.4 hours before the alert went out and 49 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: 1303 m above ground
0-6 km bulk shear: 41 kt
0-1 km storm-relative helicity: 48 m²/s²
0-3 km storm-relative helicity: 350 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.3

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 4, 2:27 PM MDT	Severe Thunderstorm Watch	SPC	Carter, Powder River	8 hr
Jun 3, 7:54 PM MDT	Mesoscale Discussion	SPC	Adams, Clay, Fillmore, Franklin, Gage, Hall and 17 more	2 hr
Jun 3, 8:38 PM MDT	Severe Thunderstorm Watch	SPC	Gage, Jefferson, Johnson, Lancaster, Nemaha, Otoe and 4 more	6 hr
Jun 3, 9:44 PM MDT	Mesoscale Discussion	SPC	Cass, Gage, Jefferson, Johnson, Lancaster, Nemaha and 7 more	2 hr
Jun 4, 4:23 PM MDT	Mesoscale Discussion	SPC	Blaine, Cherry, Frontier, Hayes, Hitchcock, Hooker and 5 more	2 hr
Jun 4, 5:55 PM MDT	Mesoscale Discussion	SPC	Keya Paha	95 min
Jun 4, 4:14 PM MDT	Mesoscale Discussion	SPC	Lincoln	91 min

Nearby

Mesoscale Discussions in South Dakota, 2020 Mesoscale Discussions in Nebraska, 2020 Mesoscale Discussions in Wyoming, 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.