Alert archive / South Dakota / Mesoscale Discussions in 2017

Mesoscale Discussion 1004

June 12, 201711 counties in Nebraska; 14 counties in South Dakota; 5 counties in Wyoming

The Storm Prediction Center issued this mesoscale discussion at Jun 12, 2017, 8:02 PM MDT for 11 counties in Nebraska; 14 counties in South Dakota; 5 counties in Wyoming. It was in force for 58 min.

The area

The outline as issued.

The facts

Issued
Jun 12, 2017, 8:02 PM MDT (02:02 UTC)
Expired
Jun 12, 2017, 9:00 PM MDT
In force
58 min
Issued by
the Storm Prediction Center
All 30 counties

Arthur County, NE, Box Butte County, NE, Cherry County, NE, Cheyenne County, NE, Dawes County, NE, Garden County, NE, Grant County, NE, Hooker County, NE, Morrill County, NE, Sheridan County, NE, Sioux County, NE, Bennett County, SD, Butte County, SD, Custer County, SD, Fall River County, SD, Haakon County, SD, Jackson County, SD, Jones County, SD, Lawrence County, SD, Meade County, SD, Mellette County, SD, Oglala Lakota County, SD, Pennington County, SD, Stanley County, SD, Todd County, SD, Campbell County, WY, Converse County, WY, Crook County, WY, Niobrara County, WY, Weston County, WY

The radar

The Rapid City radar (KUDX), 158 km from the middle of the area, began a volume at 02:06 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.

The nearest sounding before it

Rapid City, SD (KRAP), launched 00:00Z, 2.0 hours before the alert went out and 152 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-pSkew-T log-p diagram, Rapid City, SD at 00:00Z on 2017-06-13Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 421 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Rapid City, SD at 00:00Z on 2017-06-13The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 31 square meters per square second.19395878Sfc1 km3 km6 km9 kmRMLM
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
421 J/kg
Mixed-layer CIN
-41 J/kg
Mixed-layer LCL
1755 m above ground
0-6 km bulk shear
35 kt
0-1 km storm-relative helicity
31 m²/s²
0-3 km storm-relative helicity
149 m²/s²
Significant tornado parameter
0.1
Supercell composite
2.0

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.

IssuedProductOfficeCountiesLasted
Jun 12, 10:14 PM MDTMesoscale DiscussionSPCBox Butte, Cherry, Dawes, Grant, Hooker, Sheridan and 1 more91 min
Jun 13, 1:32 PM MDTMesoscale DiscussionSPCBlaine, Boyd, Brown, Cherry, Custer, Garfield and 12 more58 min
Jun 13, 2:13 PM MDTTornado WatchSPCAntelope, Blaine, Boyd, Brown, Custer, Garfield and 6 more7 hr
Jun 13, 2:46 PM MDTMesoscale DiscussionSPCAdams, Antelope, Boone, Buffalo, Burt, Butler and 27 more2 hr
Jun 13, 4:25 PM MDTSevere Thunderstorm WatchSPCAdams, Boone, Burt, Butler, Cass, Cedar and 33 more8 hr
Jun 13, 4:43 PM MDTMesoscale DiscussionSPCBoyd, Holt, Knox, Rock2 hr
Jun 12, 10:28 PM MDTSevere Thunderstorm WatchSPCBeadle, Brown, Brule, Buffalo, Clark, Day and 16 more6 hr
Jun 13, 1:33 AM MDTMesoscale DiscussionSPCBeadle, Brown, Campbell, Clark, Codington, Day and 11 more57 min
Jun 12, 6:00 PM MDTMesoscale DiscussionSPCBig Horn, Hot Springs, Johnson, Natrona, Park, Sheridan and 1 more90 min

Nearby

Mesoscale Discussions in South Dakota, 2017Mesoscale Discussions in Nebraska, 2017Mesoscale Discussions in Wyoming, 2017Every mesoscale discussion in 2017

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.