Alert archive / South Dakota / Tornado Warnings in 1999

Tornado Warning 2, NWS Rapid City, SD

May 9, 1999Mellette County, South Dakota

NWS Rapid City, SD issued this tornado warning at May 9, 1999, 7:39 PM CDT for Mellette County, South Dakota. It was in force for 31 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued
May 9, 1999, 7:39 PM CDT (00:39 UTC)
Expired
May 9, 1999, 8:10 PM CDT
In force
31 min
Issued by
NWS Rapid City, SD
Area
Whole counties

County Mellette County, SD

The radar

The Rapid City radar (KUDX), 177 km from the middle of the area, began a volume at 00:40 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.

The watch it was issued in

The SPC watch in force over the same counties when this warning went out.

IssuedProductOfficeLasted
May 9, 4:30 PM CDTTornado WatchSPC6 hr

The nearest sounding before it

Aberdeen, SD (KABR), launched 00:00Z, 0.7 hours before the alert went out and 238 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 00:00Z on 1999-05-10Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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 00:00Z on 1999-05-10The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 164 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1346 m above ground
0-6 km bulk shear
47 kt
0-1 km storm-relative helicity
164 m²/s²
0-3 km storm-relative helicity
364 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.2

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
May 9, 7:00 PM CDTSevere Thunderstorm WarningUNRBennett50 min
May 9, 7:13 PM CDTSevere Thunderstorm WarningUNRJackson47 min
May 9, 7:25 PM CDTSevere Thunderstorm WarningUNRTripp50 min
May 9, 7:32 PM CDTTornado WarningUNRTripp33 min
May 9, 7:47 PM CDTSevere Thunderstorm WarningUNRMellette, Todd63 min
May 9, 7:55 PM CDTTornado WarningUNRMellette, Todd50 min
May 9, 8:19 PM CDTTornado WarningUNRMellette61 min
May 9, 8:38 PM CDTSevere Thunderstorm WarningUNRTripp47 min
May 9, 8:49 PM CDTTornado WarningUNRTodd46 min
May 9, 9:05 PM CDTSevere Thunderstorm WarningUNRCuster, Pennington35 min
May 9, 9:31 PM CDTTornado WarningUNRTodd34 min
May 9, 9:56 PM CDTFlash Flood WarningUNRMellette, Todd4 hr
May 9, 10:04 PM CDTSevere Thunderstorm WarningUNRTodd66 min
May 9, 11:11 PM CDTFlash Flood WarningUNRTripp4 hr
May 10, 2:23 AM CDTFlash Flood WarningUNRTripp6 hr

Nearby

Tornado Warnings in South Dakota, 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.