Alert archive / Illinois / Tornado Warnings in 1997

Tornado Warning 36, NWS Quad Cities, IA

July 2, 1997Stephenson County, Illinois

NWS Quad Cities, IA issued this tornado warning at Jul 2, 1997, 1:20 AM CDT for Stephenson County, Illinois. It was in force for 60 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued
Jul 2, 1997, 1:20 AM CDT (06:20 UTC)
Expired
Jul 2, 1997, 2:20 AM CDT
In force
60 min
Issued by
NWS Quad Cities, IA
Area
Whole counties

County Stephenson County, IL

The radar

The Quad Cities radar (KDVN), 112 km from the middle of the area, began a volume at 06:23 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, 6.3 hours before the alert went out and 107 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 1997-07-02Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1089 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Davenport, at 00:00Z on 1997-07-02The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 40 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
1089 J/kg
Mixed-layer CIN
-144 J/kg
Mixed-layer LCL
1458 m above ground
0-6 km bulk shear
51 kt
0-1 km storm-relative helicity
40 m²/s²
0-3 km storm-relative helicity
236 m²/s²
Significant tornado parameter
0.1
Supercell composite
1.4

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KMLI 020620 RRA
TORMLI
ILC177-020720-

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
120 AM CDT WED JUL 2 1997

* TORNADO WARNING FOR
  STEPHENSON COUNTY IN NORTH CENTRAL ILLINOIS

* UNTIL 220 AM CDT
 
* SOME LOCATIONS AFFECTED
  LENA                               AROUND 125 AM CDT
  PEARL CITY                         AROUND 130 AM CDT
  ELEROY                             AROUND 140 AM CDT
  FREEPORT                           AROUND 150 AM CDT

* AT 117 AM CDT...A POSSIBLE TORNADO WAS INDICATED BY QUAD CITIES
  IA DOPPLER RADAR 17 MILES WEST OF FREEPORT OR 3 MILES NORTHWEST OF
  KENT MOVING EAST AT 15 MPH.  IF YOU LIVE IN THE PATH OF THIS
  DANGEROUS STORM...TAKE COVER AT THIS TIME.

  THIS STORM MAY ALSO PRODUCE DAMAGING WINDS...LARGE HAIL AND
  TORRENTIAL RAINFALL

  MEYER

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 1, 11:40 PM CDTTornado WarningDVNJo Daviess60 min
Jul 2, 12:41 AM CDTTornado WarningDVNJo Daviess59 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.