Alert archive / South Dakota / Severe Thunderstorm Watches in 2002

Severe Thunderstorm Watch 655

August 29, 20024 states

The Storm Prediction Center issued this severe thunderstorm watch at Aug 29, 2002, 3:40 PM MDT for 4 states. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued
Aug 29, 2002, 3:40 PM MDT (21:40 UTC)
Expired
Aug 29, 2002, 10:00 PM MDT
In force
6 hr
Issued by
the Storm Prediction Center

Counties Carter County, MT, Powder River County, MT, Rosebud County, MT, Bowman County, ND, Butte County, SD, Custer County, SD, Harding County, SD, Lawrence County, SD, Pennington County, SD, Campbell County, WY, Crook County, WY, Weston County, WY

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Aug 29, 4:22 PM MDTSevere Thunderstorm WarningBYZRosebud53 min
Aug 29, 6:37 PM MDTSevere Thunderstorm WarningUNRLawrence38 min
Aug 29, 7:01 PM MDTSevere Thunderstorm WarningUNRButte59 min

The nearest sounding before it

Riverton, WY (KRIW), launched 12:00Z, 9.7 hours before the alert went out and 379 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, Riverton, WY at 12:00Z on 2002-08-29Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 324 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Riverton, WY at 12:00Z on 2002-08-29The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 17 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
324 J/kg
Mixed-layer CIN
-237 J/kg
Mixed-layer LCL
1208 m above ground
0-6 km bulk shear
26 kt
0-1 km storm-relative helicity
17 m²/s²
0-3 km storm-relative helicity
55 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 29, 1:05 PM MDTSevere Thunderstorm WatchSPCCarbon, Sweetwater7 hr
Aug 29, 1:30 PM MDTSevere Thunderstorm WatchSPCBig Horn, Fremont, Hot Springs, Natrona, Park, Washakie7 hr
Aug 29, 2:45 PM MDTSevere Thunderstorm WatchSPCGoshen, Laramie, Platte7 hr

Nearby

Severe Thunderstorm Watches in South Dakota, 2002Severe Thunderstorm Watches in Montana, 2002Severe Thunderstorm Watches in Wyoming, 2002Every severe thunderstorm watch in 2002

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.