Alert archive / South Dakota / Tornado Warnings in 2002

Tornado Warning 16, NWS Sioux Falls, SD

August 9, 2002Davison County, Sanborn County, South Dakota

NWS Sioux Falls, SD issued this tornado warning at Aug 9, 2002, 6:11 PM CDT for Davison County, Sanborn County, South Dakota. It was in force for 34 min. 1 report came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued: Aug 9, 2002, 6:11 PM CDT (23:11 UTC)
Expired: Aug 9, 2002, 6:45 PM CDT
In force: 34 min
Issued by: NWS Sioux Falls, SD
Area: Counties, with a storm outline in the text

Counties Davison County, SD, Sanborn County, SD

The radar

The Sioux Falls radar (KFSD), 124 km from the middle of the area, began a volume at 23:15 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 was reported inside it

Time	Report	Where	Remark
Aug 9, 6:15 PM CDT	Hail 0.75	Letcher, SD

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 watch it was issued in

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

Issued	Product	Office	Lasted
Aug 9, 5:35 PM CDT	Severe Thunderstorm Watch	SPC	5 hr

The nearest sounding before it

Aberdeen, SD (KABR), launched 12:00Z, 11.2 hours before the alert went out and 111 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 20 J/kg
Mixed-layer CIN: -386 J/kg
Mixed-layer LCL: 1144 m above ground
0-6 km bulk shear: 19 kt
0-1 km storm-relative helicity: 50 m²/s²
0-3 km storm-relative helicity: -1 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

964 
WFUS53 KFSD 092311
TORFSD
SDC035-111-092345-

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE SIOUX FALLS SD
611 PM CDT FRI AUG 9 2002

THE NATIONAL WEATHER SERVICE IN SIOUX FALLS HAS ISSUED A

* TORNADO WARNING FOR...
  SOUTHERN SANBORN COUNTY IN EAST CENTRAL SOUTH DAKOTA
  NORTHERN DAVISON COUNTY IN SOUTHEAST SOUTH DAKOTA

* UNTIL 645 PM CDT

* AT 611 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  THUNDERSTORM WITH A DEVELOPING TORNADO 4 MILES WEST OF LETCHER...OR
  ABOUT 15 MILES NORTHWEST OF MITCHELL...MOVING EAST AT 30 MPH.

* SOME LOCATIONS AFFECTED...
  LETCHER...LOOMIS AROUND 620 PM CDT

IF YOU ARE IN THE PATH OF THIS STORM...TAKE COVER IMMEDIATELY.

LAT...LON 4398 9836 4380 9834 4378 9800 4402 9796

The office that day

Everything else NWS Sioux Falls, SD issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Aug 9, 5:23 PM CDT	Severe Thunderstorm Warning	FSD	Aurora, Jerauld	22 min
Aug 9, 5:27 PM CDT	Severe Thunderstorm Warning	FSD	Gregory	33 min
Aug 9, 5:56 PM CDT	Severe Thunderstorm Warning	FSD	Aurora, Sanborn	34 min
Aug 9, 5:59 PM CDT	Severe Thunderstorm Warning	FSD	Charles Mix, Gregory	46 min
Aug 9, 6:46 PM CDT	Severe Thunderstorm Warning	FSD	Charles Mix, Gregory	44 min

Nearby

Tornado Warnings in South Dakota, 2002 Every tornado warning in 2002 Tornadoes 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; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.