Alert archive / South Dakota / Severe Thunderstorm Watches in 2012

Severe Thunderstorm Watch 246

May 5, 201223 counties in South Dakota

The Storm Prediction Center issued this severe thunderstorm watch at May 5, 2012, 2:19 AM MDT for 23 counties in South Dakota. It was in force for 9 hr.

The area

The outline as issued.

The facts

Issued
May 5, 2012, 2:19 AM MDT (08:19 UTC)
Expired
May 5, 2012, 11:00 AM MDT
In force
9 hr
Issued by
the Storm Prediction Center
Largest hail expected
2 in
Strongest gust expected
60 kt
All 23 counties

Bennett County, SD, Buffalo County, SD, Butte County, SD, Custer County, SD, Dewey County, SD, Fall River County, SD, Haakon County, SD, Hand County, SD, Hughes County, SD, Hyde County, SD, Jackson County, SD, Jones County, SD, Lawrence County, SD, Lyman County, SD, Meade County, SD, Mellette County, SD, Pennington County, SD, Potter County, SD, Stanley County, SD, Sully County, SD, Todd County, SD, Tripp County, SD, Ziebach County, SD

The radar

The Rapid City radar (KUDX), 27 km from the middle of the area, began a volume at 08:19 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
5%
One or more EF2 to EF5 tornadoes
2%
Ten or more severe wind reports
20%
One or more gusts of 65 knots or more
5%
Ten or more severe hail reports
30%
One or more hailstones of 2 inches or more
20%
Six or more combined severe hail and wind reports
70%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
May 5, 2:59 AM MDTSevere Thunderstorm WarningUNRCuster, Lawrence, Pennington61 min
May 5, 3:45 AM MDTSevere Thunderstorm WarningUNRHaakon, Jackson, Pennington60 min
May 5, 3:55 AM MDTSevere Thunderstorm WarningUNRCuster, Pennington51 min
May 5, 4:20 AM MDTSevere Thunderstorm WarningUNRJackson55 min
May 5, 4:39 AM MDTSevere Thunderstorm WarningUNRCuster, Fall River66 min
May 5, 4:54 AM MDTSevere Thunderstorm WarningUNRJackson, Mellette66 min
May 5, 5:02 AM MDTSevere Thunderstorm WarningUNRTripp48 min
May 5, 5:10 AM MDTSevere Thunderstorm WarningABRJones50 min
May 5, 5:21 AM MDTSevere Thunderstorm WarningABRLyman39 min
May 5, 5:31 AM MDTSevere Thunderstorm WarningUNRJackson, Pennington59 min
May 5, 5:45 AM MDTSevere Thunderstorm WarningUNRPennington60 min
May 5, 5:50 AM MDTSevere Thunderstorm WarningABRLyman25 min
May 5, 5:58 AM MDTSevere Thunderstorm WarningABRJones, Lyman47 min
May 5, 6:45 AM MDTSevere Thunderstorm WarningABRBuffalo, Lyman45 min
May 5, 7:24 AM MDTSevere Thunderstorm WarningABRBuffalo, Hand25 min
May 5, 7:58 AM MDTSevere Thunderstorm WarningABRBuffalo, Hughes, Hyde, Lyman, Stanley, Sully47 min
May 5, 8:03 AM MDTSevere Thunderstorm WarningABRJones, Lyman42 min
May 5, 8:55 AM MDTSevere Thunderstorm WarningABRBuffalo, Hughes, Hyde, Lyman50 min
May 5, 9:29 AM MDTSevere Thunderstorm WarningABRHand, Spink31 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

Rapid City, SD (KUNR), launched 00:00Z, 8.3 hours before the alert went out and 34 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, Rapid City, SD at 00:00Z on 2012-05-05Temperature 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, Rapid City, SD at 00:00Z on 2012-05-05The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 34 square meters per square second.1939587897Sfc1 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
1750 m above ground
0-6 km bulk shear
67 kt
0-1 km storm-relative helicity
34 m²/s²
0-3 km storm-relative helicity
155 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 4, 8:54 PM MDTMesoscale DiscussionSPCUnion96 min
May 5, 2:06 AM MDTMesoscale DiscussionSPCCuster, Fall River, Haakon, Hughes, Hyde, Jackson and 9 more84 min
May 5, 5:49 AM MDTSevere Thunderstorm WatchSPCAurora, Beadle, Bon Homme, Brookings, Brule, Charles Mix and 18 more7 hr
May 5, 8:50 AM MDTMesoscale DiscussionSPCAurora, Beadle, Brookings, Brule, Buffalo, Davison and 13 more55 min
May 5, 1:09 PM MDTMesoscale DiscussionSPCUnion96 min
May 5, 2:52 PM MDTMesoscale DiscussionSPCClay, Lincoln, Union, Yankton83 min
May 5, 4:31 PM MDTTornado WatchSPCBon Homme, Clay, Union, Yankton5 hr
May 5, 5:21 PM MDTMesoscale DiscussionSPCAurora, Beadle, Bon Homme, Brule, Charles Mix, Davison and 15 more84 min
May 5, 5:46 PM MDTSevere Thunderstorm WatchSPCAurora, Beadle, Brookings, Brule, Charles Mix, Davison and 14 more6 hr

Nearby

Severe Thunderstorm Watches in South Dakota, 2012Every severe thunderstorm watch in 2012

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.