Alert archive / Wyoming / Tornado Warnings in 1999

Tornado Warning 39, NWS Rapid City, SD

August 11, 1999Crook County, Wyoming

NWS Rapid City, SD issued this tornado warning at Aug 11, 1999, 8:32 PM MDT for Crook County, Wyoming. It was in force for 48 min. 4 reports came from inside the area while it was in force.

The area

The counties it named, with what was reported inside it.

The facts

Issued
Aug 11, 1999, 8:32 PM MDT (02:32 UTC)
Expired
Aug 11, 1999, 9:20 PM MDT
In force
48 min
Issued by
NWS Rapid City, SD
Area
Whole counties

County Crook County, WY

What was reported inside it

TimeReportWhereRemark
Aug 11, 9:00 PM MDTHail 1.75Moorcroft, WYEighty houses had hail damage--mostly broken windows and damaged siding. Two police vehicles had moderate hail damage and another was totaled by hail.
Aug 11, 9:00 PM MDTThunderstorm Wind 52Moorcroft, WY
Aug 11, 9:05 PM MDTHail 2Moorcroft, WY
Aug 11, 9:16 PM MDTHail 1.75Moorcroft, WY

NCEI Storm Data entries that began inside the alert's area while it was in force. Before 2003 the local storm report archive is thin, so this is the record of what happened rather than what was phoned in.

The nearest sounding before it

Bismarck Municip, ND (KBIS), launched 00:00Z, 2.5 hours before the alert went out and 386 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 1999-08-12Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1951 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 1999-08-12The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 126 square meters per square second.193958Sfc1 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
1951 J/kg
Mixed-layer CIN
-69 J/kg
Mixed-layer LCL
806 m above ground
0-6 km bulk shear
33 kt
0-1 km storm-relative helicity
126 m²/s²
0-3 km storm-relative helicity
265 m²/s²
Significant tornado parameter
1.7
Supercell composite
13.0

Open this sounding in Storm Lab

The text

The text of this product is not in the archive. The NWS text archive before 2002 is incomplete.

The office that day

Everything else NWS Rapid City, SD issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Aug 11, 6:18 PM MDTSevere Thunderstorm WarningUNRHarding47 min
Aug 11, 7:44 PM MDTSevere Thunderstorm WarningUNRHarding61 min
Aug 11, 8:25 PM MDTSevere Thunderstorm WarningUNRTodd65 min
Aug 11, 9:06 PM MDTSevere Thunderstorm WarningUNRPerkins64 min
Aug 11, 9:07 PM MDTTornado WarningUNRPerkins63 min
Aug 11, 10:01 PM MDTSevere Thunderstorm WarningUNRButte, Lawrence64 min
Aug 11, 10:14 PM MDTSevere Thunderstorm WarningUNRHarding66 min
Aug 11, 10:34 PM MDTSevere Thunderstorm WarningUNRPerkins51 min
Aug 11, 11:19 PM MDTSevere Thunderstorm WarningUNRPerkins66 min
Aug 11, 7:15 PM MDTSevere Thunderstorm WarningUNRCampbell50 min
Aug 11, 8:05 PM MDTSevere Thunderstorm WarningUNRCampbell50 min
Aug 11, 8:19 PM MDTTornado WarningUNRCampbell36 min
Aug 11, 9:16 PM MDTTornado WarningUNRCrook64 min

Nearby

Tornado Warnings in Wyoming, 1999Every tornado warning in 1999Tornadoes in 1999

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive.