Alert archive / Iowa / Tornado Warnings in 2002

Tornado Warning 1, NWS Quad Cities, IA

April 18, 2002Benton County, Iowa

NWS Quad Cities, IA issued this tornado warning at Apr 18, 2002, 7:55 PM CDT for Benton County, Iowa. It was in force for 35 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued: Apr 18, 2002, 7:55 PM CDT (00:55 UTC)
Expired: Apr 18, 2002, 8:30 PM CDT
In force: 35 min
Issued by: NWS Quad Cities, IA
Area: Counties, with a storm outline in the text

County Benton County, IA

The radar

The Des Moines radar (KDMX), 143 km from the middle of the area, began a volume at 00:55 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.

The nearest sounding before it

Davenport, (KDVN), launched 00:00Z, 0.9 hours before the alert went out and 149 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: 1636 J/kg
Mixed-layer CIN: -24 J/kg
Mixed-layer LCL: 1702 m above ground
0-6 km bulk shear: 23 kt
0-1 km storm-relative helicity: 113 m²/s²
0-3 km storm-relative helicity: 200 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 4.3

Open this sounding in Storm Lab

The text

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

000 
WFUS53 KDVN 190055
TORMLI
IAC011-190130-

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
754 PM CDT THU APR 18 2002

THE NATIONAL WEATHER SERVICE IN THE QUAD CITIES HAS ISSUED A

* TORNADO WARNING FOR...
  BENTON COUNTY IN EAST CENTRAL IOWA

* UNTIL 830 PM CDT

* AT 752 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM WITH A LIKELY TORNADO 6 MILES NORTHWEST OF
  GARRISON...OR 4 MILES EAST OF DYSART...MOVING EAST AT 45 MPH.

* THE TORNADO IS EXPECTED TO BE NEAR...
   GARRISON BY 755 PM CDT.
   5 MILES SOUTH OF MOUNT AUBURN BY 800 PM CDT.
   VINTON BY 805 PM CDT.
   URBANA BY 815 PM CDT.

THE SAFEST PLACE TO BE DURING A TORNADO IS IN A BASEMENT OR ON THE
LOWEST FLOOR OF A BUILDING IN AN INTERIOR HALLWAY OR ROOM.

A TORNADO WATCH REMAINS IN EFFECT UNTIL 800 PM CDT THURSDAY EVENING
FOR EASTERN IOWA AND NORTHWESTERN ILLINOIS.

THIS TORNADO WARNING REPLACES THE SEVERE THUNDERSTORM WARNING THAT 
WAS IN EFFECT UNTIL 825 PM FOR BENTON COUNTY.

LAT...LON 4228 9230 4210 9230 4208 9185 4228 9185

REA

The office that day

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

Issued	Product	Office	Counties	Lasted
Apr 18, 7:51 PM CDT	Severe Thunderstorm Warning	DVN	Benton	34 min
Apr 18, 8:09 PM CDT	Tornado Warning	DVN	Buchanan	36 min
Apr 18, 8:17 PM CDT	Severe Thunderstorm Warning	DVN	Linn	33 min
Apr 18, 8:27 PM CDT	Tornado Warning	DVN	Iowa	48 min
Apr 18, 8:35 PM CDT	Tornado Warning	DVN	Jones, Linn	35 min
Apr 18, 8:44 PM CDT	Severe Thunderstorm Warning	DVN	Dubuque	31 min
Apr 18, 8:59 PM CDT	Tornado Warning	DVN	Johnson	46 min
Apr 18, 9:16 PM CDT	Severe Thunderstorm Warning	DVN	Jackson	44 min
Apr 18, 9:28 PM CDT	Tornado Warning	DVN	Cedar	32 min
Apr 18, 9:30 PM CDT	Severe Thunderstorm Warning	DVN	Clinton, Jones	45 min
Apr 18, 9:50 PM CDT	Severe Thunderstorm Warning	DVN	Scott	40 min
Apr 18, 9:59 PM CDT	Severe Thunderstorm Warning	DVN	Jackson	51 min

Nearby

Tornado Warnings in Iowa, 2002 Every tornado warning in 2002 Tornadoes in 2002

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.