Alert archive / Iowa / Tornado Warnings in 2001

Tornado Warning 66, NWS Sioux Falls, SD

August 17, 2001Plymouth County, Iowa

NWS Sioux Falls, SD issued this tornado warning at Aug 17, 2001, 5:30 PM CDT for Plymouth County, Iowa. It was in force for 30 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, 5:30 PM CDT (22:30 UTC)
Expired
Aug 17, 2001, 6:00 PM CDT
In force
30 min
Issued by
NWS Sioux Falls, SD
Area
Whole counties; the outline is the Mesonet’s reconstruction

County Plymouth County, IA

The radar

The Sioux Falls radar (KFSD), 106 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

TimeReportWhereRemark
Aug 17, 5:34 PM CDTTornado F0Remsen, IAA 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 watch it was issued in

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

IssuedProductOfficeLasted
Aug 17, 5:30 PM CDTSevere Thunderstorm WatchSPC5 hr

The nearest sounding before it

Omaha, NE (KOAX), launched 12:00Z, 10.5 hours before the alert went out and 163 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, Omaha, NE at 12:00Z on 2001-08-17Temperature 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°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Omaha, NE at 12:00Z on 2001-08-17The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 13 square meters per square second.19395878Sfc1 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
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.

252 
WFUS53 KFSD 172230
TORFSD
IAC149-172300-

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

THE NATIONAL WEATHER SERVICE IN SIOUX FALLS HAS ISSUED A

* TORNADO WARNING FOR...
  EASTERN PLYMOUTH COUNTY IN NORTHWEST IOWA

* UNTIL 600 PM CDT

* AT 530 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  TORNADO 4 MILES EAST OF LE MARS...MOVING SOUTHEAST AT 20 MPH.

* THE TORNADO WILL BE NEAR...
  REMSEN AROUND 535 PM CDT

LAT...LON 4289 9609 4275 9626 4257 9599 4275 9587

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 17, 4:07 PM CDTSevere Thunderstorm WarningFSDLyon23 min
Aug 17, 4:27 PM CDTSevere Thunderstorm WarningFSDLyon, Sioux33 min
Aug 17, 4:57 PM CDTSevere Thunderstorm WarningFSDSioux33 min
Aug 17, 5:04 PM CDTSevere Thunderstorm WarningFSDCherokee, Plymouth26 min
Aug 17, 5:15 PM CDTTornado WarningFSDSioux30 min
Aug 17, 5:22 PM CDTSevere Thunderstorm WarningFSDWoodbury23 min
Aug 17, 5:28 PM CDTTornado WarningFSDWoodbury32 min
Aug 17, 5:37 PM CDTTornado WarningFSDCherokee23 min
Aug 17, 5:43 PM CDTTornado WarningFSDSioux32 min
Aug 17, 5:55 PM CDTTornado WarningFSDCherokee, Plymouth50 min
Aug 17, 5:55 PM CDTTornado WarningFSDWoodbury35 min
Aug 17, 6:30 PM CDTTornado WarningFSDWoodbury15 min
Aug 17, 6:39 PM CDTTornado WarningFSDIda, Woodbury51 min
Aug 17, 6:44 PM CDTSevere Thunderstorm WarningFSDCherokee, Plymouth16 min

Nearby

Tornado Warnings in Iowa, 2001Every tornado warning in 2001Tornadoes 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.