Alert archive / South Dakota / Mesoscale Discussions in 2006

Mesoscale Discussion 955

May 23, 20064 states

The Storm Prediction Center issued this mesoscale discussion at May 23, 2006, 5:40 PM CDT for 4 states. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
May 23, 2006, 5:40 PM CDT (22:40 UTC)
Expired
May 23, 2006, 7:45 PM CDT
In force
2 hr
Issued by
the Storm Prediction Center
All 55 counties

Lyon County, IA, Plymouth County, IA, Sioux County, IA, Pipestone County, MN, Rock County, MN, Antelope County, NE, Boone County, NE, Butler County, NE, Cedar County, NE, Colfax County, NE, Cuming County, NE, Dakota County, NE, Dixon County, NE, Dodge County, NE, Greeley County, NE, Howard County, NE, Knox County, NE, Madison County, NE, Merrick County, NE, Nance County, NE, Pierce County, NE, Platte County, NE, Polk County, NE, Sherman County, NE, Stanton County, NE, Thurston County, NE, Wayne County, NE, Wheeler County, NE, Beadle County, SD, Bon Homme County, SD, Brookings County, SD, Brown County, SD, Clark County, SD, Clay County, SD, Codington County, SD, Davison County, SD, Day County, SD, Deuel County, SD, Douglas County, SD, Grant County, SD, Hamlin County, SD, Hanson County, SD, Hutchinson County, SD, Kingsbury County, SD, Lake County, SD, Lincoln County, SD, McCook County, SD, Miner County, SD, Minnehaha County, SD, Moody County, SD, Sanborn County, SD, Spink County, SD, Turner County, SD, Union County, SD, Yankton County, SD

The radar

The Sioux Falls radar (KFSD), 113 km from the middle of the area, began a volume at 22:42 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

Aberdeen, SD (KABR), launched 12:00Z, 10.7 hours before the alert went out and 197 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, Aberdeen, SD at 12:00Z on 2006-05-23Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 303 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, Aberdeen, SD at 12:00Z on 2006-05-23The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 24 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
303 J/kg
Mixed-layer CIN
-431 J/kg
Mixed-layer LCL
1445 m above ground
0-6 km bulk shear
3 kt
0-1 km storm-relative helicity
24 m²/s²
0-3 km storm-relative helicity
35 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.2

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
May 23, 6:40 PM CDTSevere Thunderstorm WatchSPCBuena Vista, Cherokee, Clay, Dickinson, Ida, Lyon and 5 more6 hr
May 23, 5:01 PM CDTMesoscale DiscussionSPCBecker, Big Stone, Chippewa, Clay, Douglas, Grant and 12 more119 min
May 22, 9:23 PM CDTMesoscale DiscussionSPCBanner, Box Butte, Cheyenne, Dawes, Deuel, Garden and 4 more97 min
May 22, 9:37 PM CDTMesoscale DiscussionSPCArthur, Chase, Deuel, Dundy, Garden, Hayes and 4 more53 min
May 22, 10:08 PM CDTSevere Thunderstorm WatchSPCArthur, Chase, Cherry, Deuel, Dundy, Frontier and 12 more6 hr
May 22, 11:32 PM CDTMesoscale DiscussionSPCArthur, Chase, Cherry, Deuel, Dundy, Frontier and 13 more88 min
May 23, 2:05 AM CDTMesoscale DiscussionSPCArthur, Blaine, Brown, Chase, Cherry, Cheyenne and 20 more85 min
May 23, 12:12 PM CDTMesoscale DiscussionSPCAdams, Antelope, Boone, Boyd, Buffalo, Butler and 36 more93 min
May 23, 2:10 PM CDTTornado WatchSPCAntelope, Blaine, Boone, Boyd, Brown, Butler and 22 more7 hr
May 23, 3:00 PM CDTMesoscale DiscussionSPCAdams, Buffalo, Clay, Dawson, Fillmore, Franklin and 14 more2 hr
May 23, 3:30 PM CDTSevere Thunderstorm WatchSPCAdams, Buffalo, Clay, Dawson, Fillmore, Franklin and 16 more5 hr

Nearby

Mesoscale Discussions in South Dakota, 2006Mesoscale Discussions in Nebraska, 2006Mesoscale Discussions in Iowa, 2006Every mesoscale discussion in 2006

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.