Alert archive / Iowa / Tornado Warnings in 1998

Tornado Warning 3, NWS Quad Cities, IA

April 7, 1998Lee County, Iowa

NWS Quad Cities, IA issued this tornado warning at Apr 7, 1998, 4:30 PM CDT for Lee County, Iowa. It was in force for 35 min. 4 reports 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: Apr 7, 1998, 4:30 PM CDT (21:30 UTC)
Expired: Apr 7, 1998, 5:05 PM CDT
In force: 35 min
Issued by: NWS Quad Cities, IA
Area: Whole counties

County Lee County, IA

The radar

The Quad Cities radar (KDVN), 131 km from the middle of the area, began a volume at 21:32 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

Time	Report	Where
Apr 7, 4:36 PM CDT	Hail 1.75	Argyle, IA
Apr 7, 4:45 PM CDT	Tornado F0	Montrose, IA
Apr 7, 5:00 PM CDT	Tornado F0	Ft Madison, IA
Apr 7, 5:02 PM CDT	Tornado F0	New Boston, IA

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 7, 2:00 PM CDT	Tornado Watch	SPC	6 hr

The nearest sounding before it

Davenport, (KDVN), launched 12:00Z, 9.5 hours before the alert went out and 136 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 1589 m above ground
0-6 km bulk shear: 20 kt
0-1 km storm-relative helicity: 101 m²/s²
0-3 km storm-relative helicity: 31 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.

734 
WFUS1 KMLI 072131 RRA
TORMLI
IAC111-072205-

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
430 PM CDT TUE APR 7 1998

* TORNADO WARNING FOR
  LEE COUNTY - SOUTHEASTERN IOWA

* UNTIL 505 PM CDT
 
* SOME LOCATIONS AFFECTED BY THIS TORNADO
  SANDUSKY                                   AROUND 435 PM CDT
  NEW BOSTON                                 AROUND 445 PM CDT
  MONTROSE                                   AROUND 445 PM CDT
  DONNELLSON                                 AROUND 450 PM CDT
  FRANKLIN                                   AROUND 500 PM CDT

* AT 429 PM CDT...DOPPLER RADAR AND SPOTTER REPORTS INDICATED A
  TORNADO 16 MILES SOUTHWEST OF FT MADISON OR 6 MILES SOUTHWEST OF
  NEW BOSTON MOVING NORTHEAST AT 25 MPH.

GO TO THE BASEMENT AND GET UNDER A WORKBENCH OR STURDY PIECE OF
FURNITURE. IF NO BASEMENT IS AVAILABLE...GO TO A SMALL INTERIOR
ROOM ON THE LOWEST FLOOR

HENDRICKS
 

&

The office that day

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

Issued	Product	Office	Counties	Lasted
Apr 7, 4:28 PM CDT	Severe Thunderstorm Warning	DVN	Lee	47 min
Apr 7, 4:36 PM CDT	Severe Thunderstorm Warning	DVN	Van Buren	34 min
Apr 7, 5:05 PM CDT	Tornado Warning	DVN	Lee	35 min

Nearby

Tornado Warnings in Iowa, 1998 Every tornado warning in 1998 Tornadoes in 1998

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.