Alert archive / South Dakota / Mesoscale Discussions in 2012

Mesoscale Discussion 1324

June 30, 2012Sioux County, North Dakota; 20 counties in South Dakota

The Storm Prediction Center issued this mesoscale discussion at Jun 30, 2012, 3:53 PM CDT for Sioux County, North Dakota; 20 counties in South Dakota. It was in force for 97 min.

The area

The outline as issued.

The facts

Issued
Jun 30, 2012, 3:53 PM CDT (20:53 UTC)
Expired
Jun 30, 2012, 5:30 PM CDT
In force
97 min
Issued by
the Storm Prediction Center
Chance of a watch
40%
All 21 counties

Sioux County, ND, Bennett County, SD, Corson County, SD, Custer County, SD, Dewey County, SD, Fall River County, SD, Haakon County, SD, Hughes 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, Potter County, SD, Stanley County, SD, Sully County, SD, Walworth County, SD, Ziebach County, SD

The radar

The Rapid City radar (KUDX), 68 km from the middle of the area, began a volume at 20:53 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

Bismarck Municip, ND (KBIS), launched 12:00Z, 8.9 hours before the alert went out and 282 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, Bismarck Municip, ND at 12:00Z on 2012-06-30Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 269 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, Bismarck Municip, ND at 12:00Z on 2012-06-30The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 159 square meters per square second.193958Sfc1 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
269 J/kg
Mixed-layer CIN
-371 J/kg
Mixed-layer LCL
1200 m above ground
0-6 km bulk shear
50 kt
0-1 km storm-relative helicity
159 m²/s²
0-3 km storm-relative helicity
419 m²/s²
Significant tornado parameter
0.0
Supercell composite
17.9

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.

IssuedProductOfficeCountiesLasted
Jun 30, 3:48 AM CDTMesoscale DiscussionSPCMcHenry, McLean, Mountrail, Sheridan, Ward, Wells87 min
Jun 30, 4:57 PM CDTSevere Thunderstorm WatchSPCBurleigh, Emmons, Kidder, Logan, McIntosh, Sioux5 hr

Nearby

Mesoscale Discussions in South Dakota, 2012Mesoscale Discussions in North Dakota, 2012Every mesoscale discussion in 2012

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.