Alert archive / South Dakota / Severe Thunderstorm Watches in 2007

Severe Thunderstorm Watch 565

August 7, 20074 counties in Montana; 12 counties in South Dakota; Campbell County, Crook County, Weston County, Wyoming

The Storm Prediction Center issued this severe thunderstorm watch at Aug 7, 2007, 1:59 PM MDT for 4 counties in Montana; 12 counties in South Dakota; Campbell County, Crook County, Weston County, Wyoming. It was in force for 7 hr.

The area

The outline as issued.

The facts

Issued
Aug 7, 2007, 1:59 PM MDT (19:59 UTC)
Expired
Aug 7, 2007, 9:00 PM MDT
In force
7 hr
Issued by
the Storm Prediction Center
Largest hail expected
2 in
Strongest gust expected
60 kt

Counties Carter County, MT, Custer County, MT, Fallon County, MT, Powder River County, MT, Bennett County, SD, Butte County, SD, Custer County, SD, Fall River County, SD, Haakon County, SD, Harding County, SD, Jackson County, SD, Lawrence County, SD, Meade County, SD, Pennington County, SD, Perkins County, SD, Ziebach County, SD, Campbell County, WY, Crook County, WY, Weston County, WY

The radar

The Rapid City radar (KUDX), 129 km from the middle of the area, began a volume at 20:01 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
70%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Aug 7, 2:13 PM MDTSevere Thunderstorm WarningUNRButte, Meade62 min
Aug 7, 2:15 PM MDTSevere Thunderstorm WarningUNR60 min
Aug 7, 2:18 PM MDTSevere Thunderstorm WarningUNRWeston42 min
Aug 7, 3:05 PM MDTSevere Thunderstorm WarningUNRJackson55 min
Aug 7, 3:06 PM MDTSevere Thunderstorm WarningUNRHarding54 min
Aug 7, 3:11 PM MDTSevere Thunderstorm WarningUNRMeade64 min
Aug 7, 3:17 PM MDTSevere Thunderstorm WarningUNRBennett58 min
Aug 7, 3:39 PM MDTSevere Thunderstorm WarningBYZCuster21 min
Aug 7, 3:56 PM MDTSevere Thunderstorm WarningUNRBennett, Jackson64 min
Aug 7, 4:07 PM MDTSevere Thunderstorm WarningUNRMeade53 min
Aug 7, 4:48 PM MDTSevere Thunderstorm WarningUNRHarding42 min
Aug 7, 5:34 PM MDTSevere Thunderstorm WarningBYZCarter, Fallon56 min
Aug 7, 7:09 PM MDTSevere Thunderstorm WarningUNRHarding46 min
Aug 7, 7:28 PM MDTSevere Thunderstorm WarningUNRPerkins62 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 12:00Z, 8.0 hours before the alert went out and 129 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 12:00Z on 2007-08-07Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 280 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, Rapid City, SD at 12:00Z on 2007-08-07The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 32 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
280 J/kg
Mixed-layer CIN
-203 J/kg
Mixed-layer LCL
1568 m above ground
0-6 km bulk shear
35 kt
0-1 km storm-relative helicity
32 m²/s²
0-3 km storm-relative helicity
96 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
Aug 7, 1:24 PM MDTMesoscale DiscussionSPCCarter, Custer, Fallon, Powder River, Prairie, Rosebud2 hr
Aug 7, 2:51 PM MDTSevere Thunderstorm WatchSPCDawson, McCone, Prairie, Richland, Wibaux6 hr
Aug 7, 5:30 PM MDTMesoscale DiscussionSPCCarter, Custer, Dawson, Fallon, McCone, Powder River and 3 more90 min
Aug 6, 6:24 PM MDTMesoscale DiscussionSPCAurora, Bon Homme, Brule, Charles Mix, Clay, Davison and 10 more96 min

Nearby

Severe Thunderstorm Watches in South Dakota, 2007Severe Thunderstorm Watches in Montana, 2007Severe Thunderstorm Watches in Wyoming, 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.