Alert archive / South Dakota / Tornado Watches in 2008

Tornado Watch 387

May 29, 2008Plymouth County, Sioux County, Woodbury County, Iowa; Dakota County, Dixon County, Nebraska; 9 counties in South Dakota

The Storm Prediction Center issued this tornado watch at May 29, 2008, 5:26 PM CDT for Plymouth County, Sioux County, Woodbury County, Iowa; Dakota County, Dixon County, Nebraska; 9 counties in South Dakota. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued
May 29, 2008, 5:26 PM CDT (22:26 UTC)
Expired
May 29, 2008, 11:00 PM CDT
In force
6 hr
Issued by
the Storm Prediction Center
Largest hail expected
2 in
Strongest gust expected
60 kt

Counties Plymouth County, IA, Sioux County, IA, Woodbury County, IA, Dakota County, NE, Dixon County, NE, Bon Homme County, SD, Charles Mix County, SD, Clay County, SD, Douglas County, SD, Hutchinson County, SD, Lincoln County, SD, Turner County, SD, Union County, SD, Yankton County, SD

The radar

The Sioux Falls radar (KFSD), 84 km from the middle of the area, began a volume at 22:28 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
50%
One or more EF2 to EF5 tornadoes
20%
Ten or more severe wind reports
30%
One or more gusts of 65 knots or more
30%
Ten or more severe hail reports
40%
One or more hailstones of 2 inches or more
40%
Six or more combined severe hail and wind reports
70%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
May 29, 5:47 PM CDTSevere Thunderstorm WarningFSDBon Homme, Yankton28 min
May 29, 6:01 PM CDTSevere Thunderstorm WarningFSDBon Homme14 min
May 29, 6:05 PM CDTTornado WarningFSDBon Homme25 min
May 29, 6:16 PM CDTSevere Thunderstorm WarningFSDBon Homme, Yankton29 min
May 29, 6:21 PM CDTFlash Flood WarningFSDBon Homme, Yankton114 min
May 29, 6:29 PM CDTTornado WarningFSDBon Homme, Yankton31 min
May 29, 6:35 PM CDTTornado WarningFSDBon Homme25 min
May 29, 6:47 PM CDTSevere Thunderstorm WarningFSDHutchinson, Turner28 min
May 29, 6:51 PM CDTSevere Thunderstorm WarningFSDYankton24 min
May 29, 6:54 PM CDTTornado WarningFSDYankton24 min
May 29, 7:04 PM CDTSevere Thunderstorm WarningFSDClay41 min
May 29, 7:07 PM CDTTornado WarningFSDClay, Turner23 min
May 29, 7:09 PM CDTTornado WarningFSDClay36 min
May 29, 7:27 PM CDTTornado WarningFSDLincoln, Turner20 min
May 29, 7:28 PM CDTTornado WarningFSDClay, Union22 min
May 29, 7:33 PM CDTSevere Thunderstorm WarningFSDSioux42 min
May 29, 8:02 PM CDTSevere Thunderstorm WarningFSDPlymouth19 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, 10.4 hours before the alert went out and 203 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 2008-05-29Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCLEL10008507005003002001001 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 2008-05-29The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 88 square meters per square second.1939587897117Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
469 m above ground
0-6 km bulk shear
37 kt
0-1 km storm-relative helicity
88 m²/s²
0-3 km storm-relative helicity
91 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.3

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 28, 11:41 PM CDTMesoscale DiscussionSPCLyon, Osceola, Plymouth, Sioux94 min
May 29, 5:32 AM CDTMesoscale DiscussionSPCBuena Vista, Calhoun, Carroll, Cherokee, Clay, Crawford and 12 more118 min
May 29, 5:43 PM CDTMesoscale DiscussionSPCBenton, Black Hawk, Bremer, Buchanan, Cedar, Chickasaw and 10 more2 hr
May 29, 5:55 PM CDTMesoscale DiscussionSPCFremont, Harrison, Mills, Monona, Montgomery, Page and 2 more35 min
May 29, 6:43 PM CDTTornado WatchSPCFremont, Harrison, Mills, Monona, Montgomery, Page and 2 more7 hr
May 29, 12:24 PM CDTMesoscale DiscussionSPCBanner, Cheyenne, Kimball, Scotts Bluff96 min
May 29, 1:33 PM CDTTornado WatchSPCArthur, Banner, Box Butte, Chase, Cherry, Cheyenne and 14 more7 hr
May 29, 1:44 PM CDTMesoscale DiscussionSPCBlaine, Custer, Dawson, Frontier, Furnas, Gosper and 9 more61 min
May 29, 2:30 PM CDTTornado Watch PDSSPCAdams, Antelope, Blaine, Boone, Boyd, Brown and 44 more8 hr
May 29, 3:55 PM CDTMesoscale DiscussionSPCAntelope, Blaine, Boyd, Brown, Cherry, Garfield and 10 more95 min
May 29, 5:07 PM CDTMesoscale DiscussionSPCDakota, Dixon23 min

Nearby

Tornado Watches in South Dakota, 2008Tornado Watches in Iowa, 2008Tornado Watches in Nebraska, 2008Every tornado watch in 2008

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.