Alert archive / Iowa / Tornado Warnings in 1997

Tornado Warning 39, NWS Quad Cities, IA

July 21, 1997Muscatine County, Scott County, Iowa; Rock Island County, Illinois

NWS Quad Cities, IA issued this tornado warning at Jul 21, 1997, 3:56 PM CDT for Muscatine County, Scott County, Iowa; Rock Island County, Illinois. It was in force for 49 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 21, 1997, 3:56 PM CDT (20:56 UTC)
Expired
Jul 21, 1997, 4:45 PM CDT
In force
49 min
Issued by
NWS Quad Cities, IA
Area
Whole counties

Counties Muscatine County, IA, Scott County, IA, Rock Island County, IL

The radar

The Quad Cities radar (KDVN), 18 km from the middle of the area, began a volume at 20:59 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 12:00Z, 8.9 hours before the alert went out and 24 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 12:00Z on 1997-07-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 101 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 12:00Z on 1997-07-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 155 square meters per square second.1939Sfc1 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
101 J/kg
Mixed-layer CIN
-90 J/kg
Mixed-layer LCL
821 m above ground
0-6 km bulk shear
20 kt
0-1 km storm-relative helicity
155 m²/s²
0-3 km storm-relative helicity
163 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.1

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KMLI 212058 RRA
TORMLI
IAC139-163-ILC161-212145-

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
356 PM CDT MON JUL 21 1997

* TORNADO WARNING FOR
  MUSCATINE COUNTY IN EAST CENTRAL IOWA
  SCOTT COUNTY IN EAST CENTRAL IOWA
  ROCK ISLAND COUNTY IN NORTHWESTERN ILLINOIS

* UNTIL 445 PM CDT
 
* SOME LOCATIONS AFFECTED
  PLAINVIEW                          AROUND 357 PM CDT
  EDGINGTON                          AROUND 357 PM CDT
  BLUE GRASS                         AROUND 357 PM CDT
  WALCOTT                            AROUND 357 PM CDT
  MAYSVILLE STENDER AIRPORT          AROUND 400 PM CDT
  ANDALUSIA                          AROUND 405 PM CDT
  BUFFALO                            AROUND 405 PM CDT
  BUFFALO HGTS                       AROUND 405 PM CDT
  MAYSVILLE                          AROUND 405 PM CDT
  DAVENPORT                          AROUND 430 PM CDT
  ROCK ISLAND                        AROUND 430 PM CDT

* AT 354 PM CDT...A POSSIBLE TORNADO WAS INDICATED BY QUAD CITIES
  IA DOPPLER RADAR AND SPOTTER REPORTS 12 MILES WEST OF QUAD CITIES
  OR 1 MILE NORTHWEST OF BLUE GRASS MOVING EAST AT 15 MPH.

STORMS HAD DEVELOPED RAPIDLY ALONG A FRONTAL BOUNDARY LOCATED
ACROSS THE AREA.  ANY OF THESE STORMS ARE CAPABLE OF PRODUCING
SHORT LIVED TORNADOES.
 
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 BASEMZENT 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.

TEH/TPH

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 20, 10:18 PM CDTSevere Thunderstorm WarningDVNJackson62 min
Jul 20, 10:35 PM CDTSevere Thunderstorm WarningDVNClinton65 min
Jul 21, 3:53 PM CDTTornado WarningDVNCedar47 min
Jul 20, 11:23 PM CDTSevere Thunderstorm WarningDVNWhiteside67 min

Nearby

Tornado Warnings in Iowa, 1997Tornado 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.