Alert archive / Illinois / Tornado Warnings in 1997

Tornado Warning 21, NWS Quad Cities, IA

May 18, 1997Henry County, Illinois

NWS Quad Cities, IA issued this tornado warning at May 18, 1997, 8:13 PM CDT for Henry County, Illinois. It was in force for 47 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, 8:13 PM CDT (01:13 UTC)
Expired
May 18, 1997, 9:00 PM CDT
In force
47 min
Issued by
NWS Quad Cities, IA
Area
Whole counties

County Henry County, IL

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

TimeReportWhereRemark
May 18, 8:17 PM CDTHail 1Colona, IL

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 18, 5:30 PM CDTTornado WatchSPC6 hr

The nearest sounding before it

Davenport, (KDVN), launched 00:00Z, 1.2 hours before the alert went out and 43 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 00:00Z on 1997-05-19Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2339 joules per kilogram.LCLLFCEL10008507005003002001001 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 00:00Z on 1997-05-19The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 145 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
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.

280 
WFUS1 KMLI 190114 RRA
TORMLI
ILC073-190200-

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

* TORNADO WARNING FOR
  HENRY COUNTY ILLINOIS - IN NORTHWESTERN ILLINOIS

* UNTIL 900 PM CDT
 
* THIS TORNADO WILL REACH NEAR
  GENESEO                            AROUND 815 PM CDT
  ATKINSON                           AROUND 825 PM CDT
  HOOPPOLE                           AROUND 835 PM CDT
  ANNAWAN                            AROUND 835 PM CDT
  KEWANEE                            AROUND 840 PM CDT

* AT 813 PM CDT...A POSSIBLE TORNADO WAS INDICATED BY QUAD CITIES
  IA DOPPLER RADAR 24 MILES NORTHWEST OF KEWANEE OR 6 MILES
  NORTHWEST OF GENESEO MOVING EAST AT 40 MPH.
 
DO NOT USE YOUR CAR TO OUTRUN A TORNADO. LEAVE THE CAR AND GO TO
A STRONG BUILDING. IF NO STRUCTURE IS NEARBY...GO TO A DITCH OR
LOW SPOT.

HENDRICKS

The office that day

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

IssuedProductOfficeCountiesLasted
May 18, 7:10 PM CDTSevere Thunderstorm WarningDVNBureau50 min
May 18, 8:01 PM CDTTornado WarningDVNRock Island49 min
May 18, 8:03 PM CDTSevere Thunderstorm WarningDVNHenderson52 min
May 18, 8:26 PM CDTSevere Thunderstorm WarningDVNWarren49 min
May 18, 8:38 PM CDTSevere Thunderstorm WarningDVNBureau47 min
May 18, 8:46 PM CDTTornado WarningDVNBureau49 min
May 18, 8:50 PM CDTSevere Thunderstorm WarningDVNHenderson45 min
May 18, 8:59 PM CDTSevere Thunderstorm WarningDVNMercer36 min
May 18, 9:07 PM CDTTornado WarningDVNWarren48 min
May 18, 9:14 PM CDTTornado WarningDVNPutnam31 min

Nearby

Tornado Warnings in Illinois, 1997Every tornado warning in 1997Tornadoes 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.