Alert archive / South Dakota / Tornado Watches in 2006

Tornado Watch 277

May 2, 20064 states

The Storm Prediction Center issued this tornado watch at May 2, 2006, 3:06 PM CDT for 4 states. It was in force for 7 hr.

The area

The outline as issued.

The facts

Issued
May 2, 2006, 3:06 PM CDT (20:06 UTC)
Expired
May 2, 2006, 10:00 PM CDT
In force
7 hr
Issued by
the Storm Prediction Center
Largest hail expected
2 in
Strongest gust expected
60 kt
All 47 counties

Cherokee County, IA, Ida County, IA, Lyon County, IA, Monona County, IA, O'Brien County, IA, Osceola County, IA, Plymouth County, IA, Sioux County, IA, Woodbury County, IA, Lincoln County, MN, Lyon County, MN, Murray County, MN, Nobles County, MN, Pipestone County, MN, Rock County, MN, Burt County, NE, Cedar County, NE, Cuming County, NE, Dakota County, NE, Dixon County, NE, Madison County, NE, Pierce County, NE, Stanton County, NE, Thurston County, NE, Wayne County, NE, Beadle County, SD, Brookings County, SD, Clark County, SD, Clay County, SD, Codington County, SD, Davison County, SD, Deuel County, SD, Grant County, SD, Hamlin County, SD, Hanson 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), 42 km from the middle of the area, began a volume at 20:08 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
30%
One or more gusts of 65 knots or more
20%
Ten or more severe hail reports
60%
One or more hailstones of 2 inches or more
30%
Six or more combined severe hail and wind reports
80%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
May 2, 4:20 PM CDTSevere Thunderstorm WarningFSDClay25 min
May 2, 4:35 PM CDTSevere Thunderstorm WarningFSDUnion25 min
May 2, 4:59 PM CDTSevere Thunderstorm WarningFSDUnion31 min
May 2, 5:08 PM CDTSevere Thunderstorm WarningFSDSioux24 min
May 2, 6:19 PM CDTSevere Thunderstorm WarningABRHamlin26 min
May 2, 6:20 PM CDTTornado WarningFSDKingsbury25 min
May 2, 6:35 PM CDTTornado WarningFSDBrookings17 min
May 2, 6:41 PM CDTTornado WarningFSDKingsbury8 min
May 2, 7:05 PM CDTSevere Thunderstorm WarningABRCodington, Deuel25 min
May 2, 7:31 PM CDTSevere Thunderstorm WarningABRDeuel29 min
May 2, 7:40 PM CDTSevere Thunderstorm WarningOAXCuming35 min
May 2, 7:47 PM CDTSevere Thunderstorm WarningOAXStanton23 min
May 2, 8:16 PM CDTSevere Thunderstorm WarningOAXCuming29 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

Omaha, NE (KOAX), launched 12:00Z, 8.1 hours before the alert went out and 275 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, Omaha, NE at 12:00Z on 2006-05-02Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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, Omaha, NE at 12:00Z on 2006-05-02The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 150 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1669 m above ground
0-6 km bulk shear
50 kt
0-1 km storm-relative helicity
150 m²/s²
0-3 km storm-relative helicity
186 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 2, 2:23 PM CDTMesoscale DiscussionSPCCherokee, Lyon, Monona, O'Brien, Osceola, Plymouth and 2 more2 hr
May 2, 5:46 PM CDTMesoscale DiscussionSPCBuena Vista, Cherokee, Clay, Dickinson, Ida, Lyon and 6 more89 min

Nearby

Tornado Watches in South Dakota, 2006Tornado Watches in Nebraska, 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.