Alert archive / South Dakota / Mesoscale Discussions in 2007

Mesoscale Discussion 690

May 4, 20077 counties in Nebraska; 15 counties in South Dakota

The Storm Prediction Center issued this mesoscale discussion at May 4, 2007, 8:49 PM CDT for 7 counties in Nebraska; 15 counties in South Dakota. It was in force for 56 min.

The area

The outline as issued.

The facts

Issued
May 4, 2007, 8:49 PM CDT (01:49 UTC)
Expired
May 4, 2007, 9:45 PM CDT
In force
56 min
Issued by
the Storm Prediction Center
Concerning
Tornado watch 226
All 22 counties

Antelope County, NE, Cedar County, NE, Dixon County, NE, Knox County, NE, Madison County, NE, Pierce County, NE, Wayne County, NE, Aurora County, SD, Beadle County, SD, Bon Homme County, SD, Charles Mix County, SD, Clay County, SD, Davison County, SD, Douglas County, SD, Hanson County, SD, Hutchinson County, SD, Jerauld County, SD, Kingsbury County, SD, Miner County, SD, Sanborn County, SD, Turner County, SD, Yankton County, SD

The radar

The Sioux Falls radar (KFSD), 106 km from the middle of the area, began a volume at 01:50 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 00:00Z, 1.8 hours before the alert went out and 172 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 00:00Z on 2007-05-05Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 121 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 00:00Z on 2007-05-05The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 31 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
121 J/kg
Mixed-layer CIN
-55 J/kg
Mixed-layer LCL
727 m above ground
0-6 km bulk shear
30 kt
0-1 km storm-relative helicity
31 m²/s²
0-3 km storm-relative helicity
50 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.3

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 4, 7:26 PM CDTTornado WatchSPCAdams, Blaine, Boyd, Brown, Buffalo, Clay and 28 more7 hr
May 4, 8:29 PM CDTMesoscale DiscussionSPCChase, Dundy, Hayes, Hitchcock, Perkins91 min
May 4, 9:22 PM CDTTornado WatchSPCAntelope, Boone, Cedar, Knox, Pierce11 hr
May 4, 9:41 PM CDTMesoscale DiscussionSPCAdams, Blaine, Brown, Buffalo, Custer, Franklin and 16 more94 min
May 4, 10:34 PM CDTMesoscale DiscussionSPCButler, Colfax, Cuming, Dodge, Gage, Jefferson and 8 more56 min
May 4, 11:28 PM CDTMesoscale DiscussionSPCChase, Dundy, Hayes, Perkins92 min
May 5, 1:23 AM CDTMesoscale DiscussionSPCAdams, Antelope, Blaine, Boone, Brown, Buffalo and 52 more67 min
May 5, 1:30 AM CDTTornado WatchSPCAdams, Antelope, Arthur, Blaine, Boone, Boyd and 60 more7 hr
May 5, 3:00 AM CDTMesoscale DiscussionSPCAdams, Antelope, Arthur, Blaine, Boone, Boyd and 60 more90 min
May 5, 6:59 AM CDTMesoscale DiscussionSPCAdams, Antelope, Boone, Buffalo, Butler, Cedar and 41 more61 min
May 5, 8:52 AM CDTMesoscale DiscussionSPCFrontier, Furnas, Harlan, Hayes, Hitchcock, Red Willow53 min
May 5, 9:51 AM CDTTornado Watch PDSSPCAdams, Blaine, Boone, Buffalo, Chase, Clay and 34 more12 hr
May 5, 10:35 AM CDTMesoscale DiscussionSPCAntelope, Boyd, Brown, Burt, Cedar, Cherry and 13 more85 min
May 5, 10:55 AM CDTTornado WatchSPCAntelope, Boyd, Brown, Cedar, Dakota, Dixon and 7 more6 hr
May 5, 11:32 AM CDTMesoscale DiscussionSPCAdams, Buffalo, Dawson, Franklin, Furnas, Gosper and 4 more88 min
May 5, 1:01 PM CDTMesoscale DiscussionSPCBoyd, Cedar, Dakota, Dixon, Holt, Knox and 2 more89 min
May 5, 1:45 PM CDTMesoscale DiscussionSPCArthur, Box Butte, Cherry, Dawes, Deuel, Garden and 8 more2 hr
May 5, 2:32 PM CDTMesoscale DiscussionSPCButler, Cass, Colfax, Cuming, Dodge, Fillmore and 14 more28 min
May 5, 2:42 PM CDTTornado Watch PDSSPCBurt, Butler, Cass, Colfax, Cuming, Dodge and 20 more7 hr
May 5, 4:09 PM CDTMesoscale DiscussionSPCBoyd, Cedar, Dakota, Dixon, Holt, Keya Paha and 4 more96 min
May 5, 4:33 PM CDTTornado Watch PDSSPCAntelope, Boyd, Brown, Cedar, Cherry, Dakota and 8 more6 hr

Nearby

Mesoscale Discussions in South Dakota, 2007Mesoscale Discussions in Nebraska, 2007Every mesoscale discussion in 2007

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.