Alert archive / South Dakota / Tornado Watches in 2006

Tornado Watch 746

August 24, 20066 counties in Iowa; 8 counties in Minnesota; 17 counties in South Dakota

The Storm Prediction Center issued this tornado watch at Aug 24, 2006, 5:51 PM CDT for 6 counties in Iowa; 8 counties in Minnesota; 17 counties in South Dakota. It was in force for 4 hr.

The area

The outline as issued.

The facts

Issued
Aug 24, 2006, 5:51 PM CDT (22:51 UTC)
Expired
Aug 24, 2006, 10:12 PM CDT
In force
4 hr
Issued by
the Storm Prediction Center
Largest hail expected
3 in
Strongest gust expected
70 kt
All 31 counties

Clay County, IA, Dickinson County, IA, Lyon County, IA, O'Brien County, IA, Osceola County, IA, Sioux County, IA, Cottonwood County, MN, Jackson County, MN, Lincoln County, MN, Lyon County, MN, Murray County, MN, Nobles County, MN, Pipestone County, MN, Rock County, MN, Aurora County, SD, Beadle County, SD, Brookings County, SD, Davison County, SD, Douglas County, SD, Hanson County, SD, Hutchinson County, SD, Jerauld 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, Turner County, SD

The radar

The Sioux Falls radar (KFSD), 58 km from the middle of the area, began a volume at 22:54 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.

What SPC expected

The probabilities SPC published with the watch, for the watch area over its life.

Two or more tornadoes
40%
One or more EF2 to EF5 tornadoes
20%
Ten or more severe wind reports
50%
One or more gusts of 65 knots or more
30%
Ten or more severe hail reports
70%
One or more hailstones of 2 inches or more
40%
Six or more combined severe hail and wind reports
90%

Warnings issued inside it

7 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.

IssuedProductOfficeCountiesLasted
Aug 24, 6:27 PM CDTTornado WarningFSDBeadle63 min
Aug 24, 7:11 PM CDTTornado WarningFSDBeadle64 min
Aug 24, 7:23 PM CDTTornado WarningFSDKingsbury52 min
Aug 24, 8:01 PM CDTTornado WarningFSDMiner36 min
Aug 24, 8:12 PM CDTTornado WarningFSDKingsbury33 min
Aug 24, 8:27 PM CDTSevere Thunderstorm WarningFSDHanson, McCook37 min
Aug 24, 9:25 PM CDTSevere Thunderstorm WarningFSDMinnehaha35 min

Discussions around it

SPC mesoscale discussions over the same counties from four hours before the watch to its end.

The nearest sounding before it

Aberdeen, SD (KABR), launched 12:00Z, 10.9 hours before the alert went out and 140 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 2006-08-24Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 3787 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 2006-08-24The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 19 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
3787 J/kg
Mixed-layer CIN
-166 J/kg
Mixed-layer LCL
769 m above ground
0-6 km bulk shear
34 kt
0-1 km storm-relative helicity
19 m²/s²
0-3 km storm-relative helicity
130 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.3

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Aug 24, 1:05 PM CDTMesoscale DiscussionSPCAllamakee115 min
Aug 24, 3:17 PM CDTTornado WatchSPCAllamakee, Howard, Mitchell, Winneshiek9 hr
Aug 24, 5:36 PM CDTMesoscale DiscussionSPCLyon54 min
Aug 24, 6:03 PM CDTMesoscale DiscussionSPCAllamakee, Howard, Mitchell, Winneshiek87 min
Aug 24, 8:44 AM CDTSevere Thunderstorm WatchSPCAnoka, Benton, Blue Earth, Brown, Carver, Chippewa and 39 more7 hr
Aug 24, 10:18 AM CDTMesoscale DiscussionSPCAnoka, Benton, Blue Earth, Brown, Carver, Chippewa and 38 more87 min
Aug 24, 11:52 AM CDTSevere Thunderstorm WatchSPCBig Stone, Clay, Grant, Otter Tail, Traverse, Wilkin5 hr
Aug 24, 2:44 PM CDTMesoscale DiscussionSPCBlue Earth, Brown, Cottonwood, Dodge, Goodhue, Lac qui Parle and 16 more3 hr
Aug 24, 2:57 PM CDTMesoscale DiscussionSPCBig Stone, Traverse, Wilkin2 hr
Aug 24, 3:40 PM CDTTornado WatchSPCBig Stone, Clay, Grant, Otter Tail, Traverse, Wilkin6 hr

Nearby

Tornado Watches in South Dakota, 2006Tornado Watches in Minnesota, 2006Tornado Watches in Iowa, 2006Every tornado watch 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.