Alert archive / South Dakota / Severe Thunderstorm Watches in 2005

Severe Thunderstorm Watch 658

July 21, 20058 counties in South Dakota

The Storm Prediction Center issued this severe thunderstorm watch at Jul 21, 2005, 6:30 PM MDT for 8 counties in South Dakota. It was in force for 5 hr.

The area

The outline as issued.

The facts

Issued
Jul 21, 2005, 6:30 PM MDT (00:30 UTC)
Expired
Jul 21, 2005, 11:00 PM MDT
In force
5 hr
Issued by
the Storm Prediction Center

Counties Dewey County, SD, Haakon County, SD, Jackson County, SD, Jones County, SD, Meade County, SD, Pennington County, SD, Stanley County, SD, Ziebach County, SD

The radar

The Rapid City radar (KUDX), 85 km from the middle of the area, began a volume at 00:32 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.

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Jul 21, 7:26 PM MDTSevere Thunderstorm WarningUNRHaakon, Meade, Pennington, Ziebach79 min
Jul 21, 8:42 PM MDTSevere Thunderstorm WarningUNRHaakon, Jackson63 min
Jul 21, 9:48 PM MDTSevere Thunderstorm WarningUNRJackson, Pennington58 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

Bismarck Municip, ND (KBIS), launched 00:00Z, 0.5 hours before the alert went out and 262 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, Bismarck Municip, ND at 00:00Z on 2005-07-22Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1122 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, Bismarck Municip, ND at 00:00Z on 2005-07-22The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 90 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
1122 J/kg
Mixed-layer CIN
-57 J/kg
Mixed-layer LCL
1835 m above ground
0-6 km bulk shear
52 kt
0-1 km storm-relative helicity
90 m²/s²
0-3 km storm-relative helicity
198 m²/s²
Significant tornado parameter
0.2
Supercell composite
5.1

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 21, 6:23 PM MDTMesoscale DiscussionSPCHaakon, Jones, Meade, Pennington, Stanley, Ziebach67 min
Jul 21, 8:16 PM MDTMesoscale DiscussionSPCCampbell, Corson, Dewey, Haakon, Jackson, Jones and 7 more89 min
Jul 21, 10:25 PM MDTMesoscale DiscussionSPCBennett, Jackson, Oglala Lakota65 min

Nearby

Severe Thunderstorm Watches in South Dakota, 2005Every severe thunderstorm watch in 2005

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.