Alert archive / Iowa / Tornado Warnings in 1997

Tornado Warning 20, NWS Quad Cities, IA

May 18, 1997Muscatine County, Iowa

NWS Quad Cities, IA issued this tornado warning at May 18, 1997, 8:10 PM CDT for Muscatine County, Iowa. It was in force for 50 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: May 18, 1997, 8:10 PM CDT (01:10 UTC)
Expired: May 18, 1997, 9:00 PM CDT
In force: 50 min
Issued by: NWS Quad Cities, IA
Area: Whole counties

County Muscatine County, IA

The radar

The Quad Cities radar (KDVN), 47 km from the middle of the area, began a volume at 01:14 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
May 18, 8:30 PM CDT	Hail 1.75	Muscatine, 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
May 18, 2:30 PM CDT	Tornado Watch	SPC	7 hr

The nearest sounding before it

Davenport, (KDVN), launched 00:00Z, 1.2 hours before the alert went out and 53 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: 2339 J/kg
Mixed-layer CIN: -25 J/kg
Mixed-layer LCL: 1544 m above ground
0-6 km bulk shear: 49 kt
0-1 km storm-relative helicity: 145 m²/s²
0-3 km storm-relative helicity: 165 m²/s²
Significant tornado parameter: 1.0
Supercell composite: 9.0

Open this sounding in Storm Lab

The text

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

266 
WFUS1 KMLI 190112 RRA
TORMLI
IAC139-190200-

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
810 PM CDT SUN MAY 18 1997

* TORNADO WARNING FOR
  MUSCATINE COUNTY - IN EAST CENTRAL IOWA

* UNTIL 900 PM CDT
 
* THIS TORNADO IS CURRENTLY EXPECTED TO REMAIN OVER RURAL AREAS

* AT 810 PM CDT...A DEVELOPING TORNADO WAS INDICATED BY QUAD CITIES
  IA DOPPLER RADAR 10 MILES NORTHEAST OF MUSCATINE OR IN THE
  VICINITY OF PLEASANT PRAIRIE MOVING EAST AT 35 MPH.
 
IF YOU ARE IN THE PATH OF A TORNADO...THE SAFEST PLACE TO BE IS
IN A BASEMENT. GET UNDER A WORKBENCH OR PIECE OF STURDY
FURNITURE. IF NO BASEMENT IS AVAILABLE...FIND SHELTER IN AN
INTERIOR ROOM SUCH AS A CLOSET ON THE LOWEST FLOOR. USE
BLANKETS...PILLOWS...OR CUSHIONS TO COVER YOUR BODY. AVOID
WINDOWS.

HENDRICKS

The office that day

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

Issued	Product	Office	Counties	Lasted
May 18, 7:24 PM CDT	Severe Thunderstorm Warning	DVN	Clinton	51 min
May 18, 7:31 PM CDT	Severe Thunderstorm Warning	DVN	Scott	49 min
May 18, 7:52 PM CDT	Tornado Warning	DVN	Scott	48 min
May 18, 8:21 PM CDT	Severe Thunderstorm Warning	DVN	Louisa	49 min
May 18, 8:22 PM CDT	Severe Thunderstorm Warning	DVN	Des Moines, Lee	48 min

Nearby

Tornado Warnings in Iowa, 1997 Every tornado warning in 1997 Tornadoes in 1997

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.