Alert archive / Iowa / Tornado Warnings in 2000

Tornado Warning 25, NWS Sioux Falls, SD

July 11, 2000Osceola County, Iowa

NWS Sioux Falls, SD issued this tornado warning at Jul 11, 2000, 8:36 PM CDT for Osceola County, Iowa. It was in force for 24 min. 1 report 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
Jul 11, 2000, 8:36 PM CDT (01:36 UTC)
Expired
Jul 11, 2000, 9:00 PM CDT
In force
24 min
Issued by
NWS Sioux Falls, SD
Area
Whole counties

County Osceola County, IA

The radar

The Sioux Falls radar (KFSD), 92 km from the middle of the area, began a volume at 01:37 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
Jul 11, 8:36 PM CDTTornado F0Sibley, 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
Jul 11, 4:30 PM CDTSevere Thunderstorm WatchSPC6 hr
Jul 11, 7:30 PM CDTSevere Thunderstorm WatchSPC6 hr

The nearest sounding before it

Minneapolis, MN (KMPX), launched 00:00Z, 1.6 hours before the alert went out and 230 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, Minneapolis, MN at 00:00Z on 2000-07-12Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 942 joules per kilogram.LCLEL10008507005003002001001 km2 km3 km6 km9 km12 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Minneapolis, MN at 00:00Z on 2000-07-12The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 52 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
942 J/kg
Mixed-layer CIN
-2 J/kg
Mixed-layer LCL
884 m above ground
0-6 km bulk shear
31 kt
0-1 km storm-relative helicity
52 m²/s²
0-3 km storm-relative helicity
125 m²/s²
Significant tornado parameter
0.2
Supercell composite
2.3

Open this sounding in Storm Lab

The text

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

000 
WFUS53 KFSD 120136
TORFSD

IAC143-120200-

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE SIOUX FALLS SD
836 PM CDT TUE JUL 11 2000

THE NATIONAL WEATHER SERVICE IN SIOUX FALLS HAS ISSUED A

* TORNADO WARNING FOR...
  NORTHERN OSCEOLA COUNTY IN NORTHWEST IOWA

* UNTIL 900 PM CDT

* AT 836 PM CDT...WEATHER SPOTTERS REPORTED A TORNADO 5 MILES NORTH
  OF SIBLEY...OR ABOUT 12 MILES SOUTHWEST OF WORTHINGTON...MOVING
  EAST AT 20 MPH.

* THE TORNADO WILL BE NEAR...
  HARRIS AROUND 900 PM CDT

DAMAGING WINDS ARE ALSO POSSIBLE WITH THESE STORMS.

THIS IS AN EXTREMELY DANGEROUS AND POTENTIALLY LIFE THREATENING
SITUATION. IF YOU ARE IN THE PATH OF THIS TORNADO...TA+KE COVER
IMMEDIATELY. GO TO THE BASEMENT. IF A BASEMENT IS NOT AVAILABLE...GO
TO A SMALL INTERIOR ROOM ON THE LOWEST FLOOR.

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 11, 7:52 PM CDTSevere Thunderstorm WarningFSDLyon23 min
Jul 11, 8:52 PM CDTTornado WarningFSDPlymouth23 min
Jul 11, 9:40 PM CDTSevere Thunderstorm WarningFSDWoodbury35 min
Jul 11, 10:04 PM CDTSevere Thunderstorm WarningFSDIda26 min

Nearby

Tornado Warnings in Iowa, 2000Every tornado warning in 2000Tornadoes in 2000

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.