Alert archive / South Dakota / Tornado Warnings in 2001

Tornado Warning 65, NWS Sioux Falls, SD

August 17, 2001Union County, South Dakota; Woodbury County, Iowa; Dakota County, Nebraska

NWS Sioux Falls, SD issued this tornado warning at Aug 17, 2001, 5:28 PM CDT for Union County, South Dakota; Woodbury County, Iowa; Dakota County, Nebraska. It was in force for 32 min. 1 report came from inside the area while it was in force.

The area

The outline the Iowa Environmental Mesonet reconstructed for it; the warning itself named whole counties, with what was reported inside it.

The facts

Issued: Aug 17, 2001, 5:28 PM CDT (22:28 UTC)
Expired: Aug 17, 2001, 6:00 PM CDT
In force: 32 min
Issued by: NWS Sioux Falls, SD
Area: Whole counties; the outline is the Mesonet’s reconstruction

Counties Woodbury County, IA, Dakota County, NE, Union County, SD

The radar

The Sioux Falls radar (KFSD), 119 km from the middle of the area, began a volume at 22:32 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 17, 5:50 PM CDT	Tornado F0	Mc Cook Lake, SD	A brief tornado caused no reported damage.

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

Omaha, NE (KOAX), launched 12:00Z, 10.5 hours before the alert went out and 135 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 1475 m above ground
0-6 km bulk shear: 24 kt
0-1 km storm-relative helicity: 13 m²/s²
0-3 km storm-relative helicity: -21 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.

044 
WFUS53 KFSD 172229
TORFSD
IAC193-NEC043-SDC127-172300-

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE SIOUX FALLS SD
528 PM CDT FRI AUG 17 2001

THE NATIONAL WEATHER SERVICE IN SIOUX FALLS HAS ISSUED A

* TORNADO WARNING FOR...
  NORTHEAST DAKOTA COUNTY IN NORTHEAST NEBRASKA
  NORTHWEST WOODBURY COUNTY IN NORTHWEST IOWA
  SOUTHEAST UNION COUNTY IN SOUTHEAST SOUTH DAKOTA

* UNTIL 600 PM CDT

* AT 528 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  TORNADO 3 MILES SOUTHWEST OF NORTH SIOUX CITY...OR ABOUT 8 MILES
  WEST OF SIOUX CITY...MOVING SOUTHEAST AT 25 MPH.

* THE TORNADO WILL BE NEAR...
  SIOUX CITY AROUND 540 PM CDT
  SOUTH SIOUX CITY AROUND 545 PM CDT

THIS IS AN EXTREMELY DANGEROUS AND LIFE THREATENING SITUATION. TAKE
COVER NOW.

LAT...LON 4260 9657 4251 9660 4241 9640 4253 9631

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 17, 4:43 PM CDT	Severe Thunderstorm Warning	FSD	Union	32 min
Aug 17, 5:12 PM CDT	Severe Thunderstorm Warning	FSD	Union	33 min
Aug 17, 4:07 PM CDT	Severe Thunderstorm Warning	FSD	Lyon	23 min
Aug 17, 4:27 PM CDT	Severe Thunderstorm Warning	FSD	Lyon, Sioux	33 min
Aug 17, 4:57 PM CDT	Severe Thunderstorm Warning	FSD	Sioux	33 min
Aug 17, 5:04 PM CDT	Severe Thunderstorm Warning	FSD	Cherokee, Plymouth	26 min
Aug 17, 5:15 PM CDT	Tornado Warning	FSD	Sioux	30 min
Aug 17, 5:22 PM CDT	Severe Thunderstorm Warning	FSD	Woodbury	23 min
Aug 17, 5:30 PM CDT	Tornado Warning	FSD	Plymouth	30 min
Aug 17, 5:37 PM CDT	Tornado Warning	FSD	Cherokee	23 min
Aug 17, 5:43 PM CDT	Tornado Warning	FSD	Sioux	32 min
Aug 17, 5:55 PM CDT	Tornado Warning	FSD	Cherokee, Plymouth	50 min
Aug 17, 5:55 PM CDT	Tornado Warning	FSD	Woodbury	35 min
Aug 17, 6:30 PM CDT	Tornado Warning	FSD	Woodbury	15 min
Aug 17, 6:39 PM CDT	Tornado Warning	FSD	Ida, Woodbury	51 min
Aug 17, 6:44 PM CDT	Severe Thunderstorm Warning	FSD	Cherokee, Plymouth	16 min

Nearby

Tornado Warnings in South Dakota, 2001 Tornado Warnings in Iowa, 2001 Tornado Warnings in Nebraska, 2001 Every tornado warning in 2001 Tornadoes in 2001

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.