Alert archive / South Dakota / Mesoscale Discussions in 2015

Mesoscale Discussion 1089

June 20, 2015Carter County, Powder River County, Montana; 11 counties in South Dakota; 4 counties in Wyoming

The Storm Prediction Center issued this mesoscale discussion at Jun 20, 2015, 2:50 PM MDT for Carter County, Powder River County, Montana; 11 counties in South Dakota; 4 counties in Wyoming. It was in force for 115 min.

The area

The outline as issued.

The facts

Issued: Jun 20, 2015, 2:50 PM MDT (20:50 UTC)
Expired: Jun 20, 2015, 4:45 PM MDT
In force: 115 min
Issued by: the Storm Prediction Center
Chance of a watch: 40%

Counties Carter County, MT, Powder River County, MT, Butte County, SD, Custer County, SD, Fall River County, SD, Haakon County, SD, Harding County, SD, Lawrence County, SD, Meade County, SD, Oglala Lakota County, SD, Pennington County, SD, Perkins County, SD, Ziebach County, SD, Campbell County, WY, Crook County, WY, Johnson County, WY, Weston County, WY

The radar

The Rapid City radar (KUDX), 98 km from the middle of the area, began a volume at 20:52 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

Bismarck Municip, ND (KBIS), launched 12:00Z, 8.8 hours before the alert went out and 343 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: 1028 m above ground
0-6 km bulk shear: 53 kt
0-1 km storm-relative helicity: -54 m²/s²
0-3 km storm-relative helicity: -6 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

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SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jun 19, 6:38 PM MDT	Mesoscale Discussion	SPC	Carter, Powder River	67 min
Jun 19, 8:29 PM MDT	Mesoscale Discussion	SPC	McPherson, Marshall	61 min
Jun 19, 9:31 PM MDT	Mesoscale Discussion	SPC	Aurora, Brule, Buffalo, Charles Mix, Douglas, Haakon and 4 more	59 min
Jun 19, 9:57 PM MDT	Severe Thunderstorm Watch PDS	SPC	Aurora, Beadle, Bennett, Bon Homme, Brookings, Brule and 34 more	5 hr
Jun 20, 12:02 AM MDT	Mesoscale Discussion	SPC	Aurora, Beadle, Brule, Buffalo, Charles Mix, Davison and 18 more	58 min

Nearby

Mesoscale Discussions in South Dakota, 2015 Mesoscale Discussions in Wyoming, 2015 Mesoscale Discussions in Montana, 2015 Every mesoscale discussion in 2015

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.