Alert archive / South Dakota / Severe Thunderstorm Watches in 2007

Severe Thunderstorm Watch 571

August 8, 200723 counties in South Dakota

The Storm Prediction Center issued this severe thunderstorm watch at Aug 8, 2007, 3:56 PM CDT for 23 counties in South Dakota. It was in force for 5 hr.

The area

The outline as issued.

The facts

Issued
Aug 8, 2007, 3:56 PM CDT (20:56 UTC)
Expired
Aug 8, 2007, 9:00 PM CDT
In force
5 hr
Issued by
the Storm Prediction Center
Largest hail expected
2 in
Strongest gust expected
60 kt
All 23 counties

Aurora County, SD, Beadle County, SD, Brown County, SD, Brule County, SD, Buffalo County, SD, Charles Mix County, SD, Clark County, SD, Codington County, SD, Davison County, SD, Day County, SD, Douglas County, SD, Edmunds County, SD, Faulk County, SD, Gregory County, SD, Hand County, SD, Hughes County, SD, Hyde County, SD, Jerauld County, SD, Lyman County, SD, Marshall County, SD, McPherson County, SD, Sanborn County, SD, Spink County, SD

The radar

The Aberdeen radar (KABR), 91 km from the middle of the area, began a volume at 20:56 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
10%
One or more EF2 to EF5 tornadoes
5%
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
20%
Six or more combined severe hail and wind reports
80%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Aug 8, 4:21 PM CDTSevere Thunderstorm WarningABREdmunds, Faulk54 min
Aug 8, 4:26 PM CDTTornado WarningABRMcPherson34 min
Aug 8, 4:37 PM CDTSevere Thunderstorm WarningABREdmunds, Faulk38 min
Aug 8, 5:01 PM CDTSevere Thunderstorm WarningABRMcPherson44 min
Aug 8, 5:12 PM CDTTornado WarningABRFaulk, Spink33 min
Aug 8, 5:24 PM CDTSevere Thunderstorm WarningABRBuffalo, Hand, Hyde66 min
Aug 8, 5:48 PM CDTSevere Thunderstorm WarningABRSpink57 min
Aug 8, 6:34 PM CDTSevere Thunderstorm WarningABRBuffalo26 min
Aug 8, 6:38 PM CDTSevere Thunderstorm WarningFSDBrule, Jerauld37 min
Aug 8, 7:19 PM CDTSevere Thunderstorm WarningABRClark, Codington, Hamlin41 min
Aug 8, 7:19 PM CDTSevere Thunderstorm WarningFSDBeadle41 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, 8.9 hours before the alert went out and 43 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 2007-08-08Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 244 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 2007-08-08The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -18 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
244 J/kg
Mixed-layer CIN
-248 J/kg
Mixed-layer LCL
973 m above ground
0-6 km bulk shear
23 kt
0-1 km storm-relative helicity
-18 m²/s²
0-3 km storm-relative helicity
-1 m²/s²
Significant tornado parameter
0.0
Supercell composite
-0.1

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Aug 8, 7:40 AM CDTMesoscale DiscussionSPCCorson, Dewey, Perkins, Ziebach95 min
Aug 8, 2:09 PM CDTMesoscale DiscussionSPCAurora, Beadle, Brookings, Brown, Brule, Buffalo and 23 more66 min
Aug 8, 6:17 PM CDTMesoscale DiscussionSPCAurora, Beadle, Bon Homme, Brown, Brule, Buffalo and 21 more58 min

Nearby

Severe Thunderstorm Watches in South Dakota, 2007Every severe thunderstorm watch 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.