Alert archive / Iowa / Tornado Warnings in 2001

Tornado Warning 73, NWS Sioux Falls, SD

August 17, 2001Ida County, Woodbury County, Iowa

NWS Sioux Falls, SD issued this tornado warning at Aug 17, 2001, 7:28 PM CDT for Ida County, Woodbury County, Iowa. It was in force for 32 min. 3 reports 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, 7:28 PM CDT (00:28 UTC)
Expired: Aug 17, 2001, 8:00 PM CDT
In force: 32 min
Issued by: NWS Sioux Falls, SD
Area: Whole counties; the outline is the Mesonet’s reconstruction

Counties Ida County, IA, Woodbury County, IA

What was reported inside it

Time	Report	Where
Aug 17, 7:30 PM CDT	Hail 0.75	Ida Grove, IA
Aug 17, 7:30 PM CDT	Hail 1	Danbury, IA
Aug 17, 7:35 PM CDT	Hail 0.88	Battle Creek, IA

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 17, 5:30 PM CDT	Severe Thunderstorm Watch	SPC	5 hr

The nearest sounding before it

Omaha, NE (KOAX), launched 00:00Z, 0.5 hours before the alert went out and 120 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: 2452 J/kg
Mixed-layer CIN: -1 J/kg
Mixed-layer LCL: 1134 m above ground
0-6 km bulk shear: 30 kt
0-1 km storm-relative helicity: 66 m²/s²
0-3 km storm-relative helicity: 166 m²/s²
Significant tornado parameter: 0.7
Supercell composite: 3.9

Open this sounding in Storm Lab

The text

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

384 
WFUS53 KFSD 180030
TORFSD
IAC093-193-180100-

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

THE NATIONAL WEATHER SERVICE IN SIOUX FALLS HAS ISSUED A

* TORNADO WARNING FOR...
  SOUTHWEST IDA COUNTY IN NORTHWEST IOWA
  SOUTHEAST WOODBURY COUNTY IN NORTHWEST IOWA

* UNTIL 800 PM CDT

* AT 728 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  TORNADO 7 MILES NORTH OF DANBURY...OR ABOUT 13 MILES WEST OF IDA
  GROVE...MOVING SOUTHEAST AT 30 MPH.

* THE TORNADO WILL BE NEAR...
  DANBURY AROUND 735 PM CDT

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

THIS TORNADO WARNING EXTENDS THE PREVIOUS TORNADO WARNING FOR PARTS 
OF THESE COUNTIES.

LAT...LON 4243 9567 4233 9587 4195 9557 4207 9532

Nearby

Tornado Warnings in Iowa, 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.