Alert archive / Iowa / Tornado Warnings in 2001

Tornado Warning 6, NWS Quad Cities, IA

April 11, 2001Iowa County, Johnson County, Iowa

NWS Quad Cities, IA issued this tornado warning at Apr 11, 2001, 4:51 PM CDT for Iowa County, Johnson County, Iowa. It was in force for 24 min. 2 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: Apr 11, 2001, 4:51 PM CDT (21:51 UTC)
Expired: Apr 11, 2001, 5:15 PM CDT
In force: 24 min
Issued by: NWS Quad Cities, IA
Area: Whole counties; the outline is the Mesonet’s reconstruction

Counties Iowa County, IA, Johnson County, IA

The radar

The Quad Cities radar (KDVN), 101 km from the middle of the area, began a volume at 21:55 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

Time	Report	Where	Remark
Apr 11, 5:00 PM CDT	Tornado F0	Oxford, IA	An F0 tornado moved across rural areas south of Oxford, and destroyed a barn and a garage at two farms. There were no injuries.
Apr 11, 5:02 PM CDT	Tornado F0	Tiffin, IA	Law enforcement reported a brief tornado touchdown in Tiffin. No damage resulted from the F0 tornado, and there were no injuries.

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
Apr 11, 12:00 PM CDT	Tornado Watch	SPC	5 hr
Apr 11, 4:00 PM CDT	Tornado Watch	SPC	6 hr

The nearest sounding before it

Davenport, (KDVN), launched 12:00Z, 9.9 hours before the alert went out and 108 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: 196 J/kg
Mixed-layer CIN: -182 J/kg
Mixed-layer LCL: 822 m above ground
0-6 km bulk shear: 63 kt
0-1 km storm-relative helicity: 336 m²/s²
0-3 km storm-relative helicity: 387 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 1.8

Open this sounding in Storm Lab

The text

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

711 
WFUS53 KDVN 112152
TORMLI
IAC095-103-112215-

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
451 PM CDT WED APR 11 2001

THE NATIONAL WEATHER SERVICE IN QUAD CITIES HAS ISSUED A

* TORNADO WARNING FOR...
  SOUTHEASTERN IOWA COUNTY IN EAST CENTRAL IOWA
  JOHNSON COUNTY IN EAST CENTRAL IOWA

* UNTIL 515 PM CDT

* AT 450 PM CDT...DOPPLER RADAR AND SPOTTERS INDICATED A DEVELOPING  
  TORNADO ALONG HIGHWAY 149...MOVING NORTHEAST AT 50 MPH.

* THE TORNADO IS EXPECTED TO BE NEAR...
  9 MILES SOUTHEAST OF OXFORD BY 500 PM CDT.
   CORALVILLE BY 505 PM CDT.
   IOWA CITY BY 510 PM CDT.

THE SAFEST PLACE TO BE DURING A TORNADO IS IN A BASEMENT. SEEK
SHELTER ON THE LOWEST FLOOR OF THE BUILDING IN AN INTERIOR HALLWAY OR
ROOM SUCH AS A CLOSET. USE BLANKETS OR PILLOWS TO COVER YOUR BODY AND
ALWAYS STAY AWAY FROM WINDOWS.


LAT...LON 4159 9196 4151 9183 4166 9149 4181 9173

MCCLURE

The office that day

Everything else NWS Quad Cities, IA issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Apr 11, 4:17 PM CDT	Tornado Warning	DVN	Keokuk	28 min
Apr 11, 4:38 PM CDT	Tornado Warning	DVN	Washington	22 min
Apr 11, 4:42 PM CDT	Tornado Warning	DVN	Benton	18 min
Apr 11, 5:10 PM CDT	Tornado Warning	DVN	Johnson, Linn	35 min
Apr 11, 5:15 PM CDT	Tornado Warning	DVN	Buchanan	30 min
Apr 11, 5:43 PM CDT	Tornado Warning	DVN	Linn	32 min

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; radar from the NEXRAD Level II archive.