Alert archive / South Dakota / Tornado Warnings in 2002
Tornado Warning 18, NWS Sioux Falls, SD
NWS Sioux Falls, SD issued this tornado warning at Aug 20, 2002, 9:10 PM CDT for Hanson County, South Dakota. It was in force for 35 min. 3 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 20, 2002, 9:10 PM CDT (02:10 UTC)
- Expired
- Aug 20, 2002, 9:45 PM CDT
- In force
- 35 min
- Issued by
- NWS Sioux Falls, SD
- Area
- Whole counties
County Hanson County, SD
The radar
The Sioux Falls radar (KFSD), 86 km from the middle of the area, began a volume at 02:09 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 20, 9:10 PM CDT | Thunderstorm Wind 52 E | Farmer, SD | |
| Aug 20, 9:10 PM CDT | Hail 0.88 | Farmer, SD | |
| Aug 20, 9:30 PM CDT | Thunderstorm Wind 52 E | Emery, SD | Thunderstorm winds caused tree damage, including small limbs blown down. |
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 20, 7:30 PM CDT | Tornado Watch | SPC | 6 hr |
The nearest sounding before it
Aberdeen, SD (KABR), launched 00:00Z, 2.2 hours before the alert went out and 145 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.
- Mixed-layer CAPE
- 1 J/kg
- Mixed-layer CIN
- -265 J/kg
- Mixed-layer LCL
- 857 m above ground
- 0-6 km bulk shear
- 53 kt
- 0-1 km storm-relative helicity
- 90 m²/s²
- 0-3 km storm-relative helicity
- 256 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.4
The text
As transmitted, in the capitals the NWS used until 2016.
375 WFUS53 KFSD 210210 TORFSD SDC061-210245- BULLETIN - EAS ACTIVATION REQUESTED TORNADO WARNING NATIONAL WEATHER SERVICE SIOUX FALLS SD 909 PM CDT TUE AUG 20 2002 THE NATIONAL WEATHER SERVICE IN SIOUX FALLS HAS ISSUED A * TORNADO WARNING FOR... HANSON COUNTY IN SOUTHEAST SOUTH DAKOTA * UNTIL 945 PM CDT * AT 909 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A THUNDERSTORM WITH A DEVELOPING TORNADO 6 MILES SOUTHWEST OF ALEXANDRIA...OR ABOUT 13 MILES SOUTHEAST OF MITCHELL...MOVING EAST AT 25 MPH. * SOME LOCATIONS AFFECTED... EMERY AROUND 930 PM CDT THIS WARNING REPLACES THE SEVERE THUNDERSTORM WARNING PREVIOUSLY ISSUED FOR THE WARNED AREA. THIS THUNDERSTORM CAN PRODUCE A TORNADO AT ANY TIME. TAKE SHELTER NOW. TAKE COVER IMMEDIATELY. ABANDON MOBILE HOMES AND FIND SHELTER IN A NEARBY STURDY BUILDING. LAT...LON 4370 9796 4352 9796 4351 9762 4371 9762 BOUSTEAD
The office that day
Everything else NWS Sioux Falls, SD issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 20, 7:17 PM CDT | Severe Thunderstorm Warning | FSD | Davison, Sanborn | 43 min |
| Aug 20, 7:25 PM CDT | Severe Thunderstorm Warning | FSD | Aurora | 35 min |
| Aug 20, 7:48 PM CDT | Severe Thunderstorm Warning | FSD | Gregory | 42 min |
| Aug 20, 8:25 PM CDT | Severe Thunderstorm Warning | FSD | Hanson | 50 min |
| Aug 20, 8:31 PM CDT | Severe Thunderstorm Warning | FSD | Davison | 29 min |
| Aug 20, 8:47 PM CDT | Severe Thunderstorm Warning | FSD | Lake, Miner | 43 min |
| Aug 20, 9:02 PM CDT | Severe Thunderstorm Warning | FSD | McCook | 43 min |
| Aug 20, 9:10 PM CDT | Tornado Warning | FSD | Hanson | 35 min |
| Aug 20, 9:17 PM CDT | Severe Thunderstorm Warning | FSD | Aurora | 43 min |
| Aug 20, 9:25 PM CDT | Severe Thunderstorm Warning | FSD | Douglas | 50 min |
| Aug 20, 9:42 PM CDT | Flash Flood Warning | FSD | Aurora, Davison | 108 min |
| Aug 20, 9:42 PM CDT | Severe Thunderstorm Warning | FSD | Minnehaha | 63 min |
| Aug 20, 9:44 PM CDT | Severe Thunderstorm Warning | FSD | McCook | 46 min |
| Aug 20, 10:11 PM CDT | Severe Thunderstorm Warning | FSD | Hutchinson | 49 min |
| Aug 21, 7:46 AM CDT | Flash Flood Warning | FSD | Minnehaha | 119 min |
| Aug 21, 6:54 PM CDT | Severe Thunderstorm Warning | FSD | Gregory | 51 min |
Nearby
Tornado Warnings in South Dakota, 2002Every tornado warning in 2002Tornadoes 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.