Alert archive / South Dakota / Mesoscale Discussions in 2018

Mesoscale Discussion 903

June 27, 2018Emmons County, McIntosh County, Sioux County, North Dakota; 23 counties in South Dakota

The Storm Prediction Center issued this mesoscale discussion at Jun 27, 2018, 2:18 AM CDT for Emmons County, McIntosh County, Sioux County, North Dakota; 23 counties in South Dakota. It was in force for 87 min.

The area

The outline as issued.

The facts

Issued
Jun 27, 2018, 2:18 AM CDT (07:18 UTC)
Expired
Jun 27, 2018, 3:45 AM CDT
In force
87 min
Issued by
the Storm Prediction Center
All 26 counties

Emmons County, ND, McIntosh County, ND, Sioux County, ND, Buffalo County, SD, Butte County, SD, Campbell County, SD, Corson County, SD, Dewey County, SD, Edmunds County, SD, Faulk County, SD, Haakon County, SD, Hand County, SD, Harding County, SD, Hughes County, SD, Hyde County, SD, Jones County, SD, Lyman County, SD, McPherson County, SD, Meade County, SD, Pennington County, SD, Perkins County, SD, Potter County, SD, Stanley County, SD, Sully County, SD, Walworth County, SD, Ziebach County, SD

The radar

The Rapid City radar (KUDX), 141 km from the middle of the area, began a volume at 07:22 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, 7.3 hours before the alert went out and 148 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 2018-06-27Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1573 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 2018-06-27The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 112 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
1573 J/kg
Mixed-layer CIN
-153 J/kg
Mixed-layer LCL
2012 m above ground
0-6 km bulk shear
52 kt
0-1 km storm-relative helicity
112 m²/s²
0-3 km storm-relative helicity
202 m²/s²
Significant tornado parameter
0.0
Supercell composite
3.3

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.

IssuedProductOfficeCountiesLasted
Jun 26, 9:05 PM CDTMesoscale DiscussionSPCAdams, Bottineau, Bowman, Dunn, Grant, Hettinger and 12 more115 min
Jun 27, 12:12 AM CDTSevere Thunderstorm WatchSPCEmmons, McIntosh, Sioux9 hr
Jun 26, 11:52 PM CDTMesoscale DiscussionSPCBrule, Buffalo, Campbell, Corson, Dewey, Haakon and 15 more113 min
Jun 27, 4:18 AM CDTMesoscale DiscussionSPCAurora, Brule, Buffalo, Charles Mix, Davison, Douglas and 10 more87 min
Jun 27, 4:34 AM CDTSevere Thunderstorm WatchSPCAurora, Beadle, Bon Homme, Brule, Charles Mix, Davison and 10 more5 hr
Jun 27, 7:25 AM CDTMesoscale DiscussionSPCAurora, Beadle, Bon Homme, Brule, Buffalo, Charles Mix and 18 more95 min

Nearby

Mesoscale Discussions in South Dakota, 2018Mesoscale Discussions in North Dakota, 2018Every mesoscale discussion in 2018

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.