Alert archive / Iowa / Tornado Warnings in 2000

Tornado Warning 2, NWS Des Moines, IA

May 11, 2000Black Hawk County, Iowa

NWS Des Moines, IA issued this tornado warning at May 11, 2000, 6:56 PM CDT for Black Hawk County, Iowa. It was in force for 29 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
May 11, 2000, 6:56 PM CDT (23:56 UTC)
Expired
May 11, 2000, 7:25 PM CDT
In force
29 min
Issued by
NWS Des Moines, IA
Area
Whole counties; the outline is the Mesonet’s reconstruction

County Black Hawk County, IA

The radar

The Des Moines radar (KDMX), 141 km from the middle of the area, began a volume at 23:55 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
May 11, 7:03 PM CDTTornado F3Cedar Falls, IAMulti-vortex, regerative tornado

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
May 11, 6:45 PM CDTTornado WatchSPC5 hr

The nearest sounding before it

Davenport, (KDVN), launched 12:00Z, 11.9 hours before the alert went out and 182 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, Davenport, at 12:00Z on 2000-05-11Temperature 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, Davenport, at 12:00Z on 2000-05-11The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 172 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
938 m above ground
0-6 km bulk shear
50 kt
0-1 km storm-relative helicity
172 m²/s²
0-3 km storm-relative helicity
291 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.1

Open this sounding in Storm Lab

The text

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

740 
WFUS53 KDMX 112357
TORDSM
IAC013-120030-

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE DES MOINES IA
656 PM CDT THU MAY 11 2000

THE NATIONAL WEATHER SERVICE IN DES MOINES HAS ISSUED A

* TORNADO WARNING FOR...
  BLACK HAWK COUNTY IN NORTHEAST IOWA

* UNTIL 725 PM CDT

* AT 656 PM CDT DOPPLER RADAR INDICATED A TORNADO 5 MILES NORTH OF
  CEDAR FALLS...OR ABOUT 9 MILES NORTHWEST OF WATERLOO...MOVING EAST
  AT 35 MPH.

* SOME LOCATIONS THREATENED THROUGH 725 PM CDT...
  WATERLOO
  ELK RUN HEIGHTS
  DUNKERTON

THIS WARNING REPLACES THE SEVERE THUNDERSTORM WARNING FOR NORTHERN 
BLACK HAWK COUNTY.  

THE SAFEST PLACE TO BE DURING A TORNADO IS IN A BASEMENT. GET UNDER A
WORKBENCH OR OTHER PIECE OF STURDY FURNITURE.

JOHNSON

LAT...LON 4263 9256 4231 9253 4231 9209 4263 9208

JOHNSON
NNNN

The office that day

Everything else NWS Des Moines, IA issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 11, 6:25 PM CDTSevere Thunderstorm WarningDMXButler30 min
May 11, 6:48 PM CDTTornado WarningDMXButler17 min
May 11, 6:53 PM CDTSevere Thunderstorm WarningDMXBlack Hawk, Bremer32 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.