Alert archive / Illinois / Tornado Warnings in 2004

Tornado Warning 3, NWS Quad Cities, IA

April 20, 2004Carroll County, Jo Daviess County, Illinois

NWS Quad Cities, IA issued this tornado warning at Apr 20, 2004, 7:35 PM CDT for Carroll County, Jo Daviess County, Illinois. It was in force for 65 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Apr 20, 2004, 7:35 PM CDT (00:35 UTC)
Expired
Apr 20, 2004, 8:40 PM CDT
In force
65 min
Issued by
NWS Quad Cities, IA
Area
Counties, with a storm outline in the text

Counties Carroll County, IL, Jo Daviess County, IL

The nearest sounding before it

Davenport, (KDVN), launched 00:00Z, 0.6 hours before the alert went out and 81 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 2004-04-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 601 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 2004-04-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 246 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
601 J/kg
Mixed-layer CIN
-5 J/kg
Mixed-layer LCL
756 m above ground
0-6 km bulk shear
36 kt
0-1 km storm-relative helicity
246 m²/s²
0-3 km storm-relative helicity
329 m²/s²
Significant tornado parameter
0.7
Supercell composite
5.8

Open this sounding in Storm Lab

The text

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

909 
WFUS53 KDVN 210035
TORDVN
ILC015-085-210140-

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
734 PM CDT TUE APR 20 2004

THE NATIONAL WEATHER SERVICE IN THE QUAD CITIES HAS ISSUED A

* TORNADO WARNING FOR...
  NORTHWESTERN CARROLL COUNTY IN NORTHWEST ILLINOIS   
  JO DAVIESS COUNTY IN NORTHWEST ILLINOIS

* UNTIL 840 PM CDT

* AT 728 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM LIKELY TO PRODUCE A TORNADO 14 MILES SOUTHWEST
  OF HANOVER...OR ABOUT 12 MILES EAST OF MAQUOKETA...MOVING NORTHEAST
  AT 25 MPH.

* THE TORNADO IS EXPECTED TO BE NEAR...
  HANOVER BY 800 PM CDT
  DERINDA CENTER BY 805 PM CDT
  ELIZABETH AND 4 MILES NORTHWEST OF MASSBACH BY 810 PM CDT
  WOODBINE AND 6 MILES SOUTHEAST OF SCHAPVILLE BY 820 PM CDT
  7 MILES NORTHWEST OF PLUM RIVER BY 825 PM CDT
  STOCKTON AND 8 MILES SOUTH OF APPLE RIVER BY 830 PM CDT

THE SAFEST PLACE TO BE IN A TORNADO IS IN A BASEMENT OR INTERIOR ROOM
OR HALLWAY ON THE LOWEST FLOOR OF A BUILDING.

THIS STORM HAS ALREADY PRODUCED A TORNADO AND REMAINS A THREAT.

LAT...LON 4212 9018 4217 9025 4224 9041 4248 9013
          4250 9003 4242 8992 4229 8992

$$

12

Nearby

Tornado Warnings in Illinois, 2004Every tornado warning in 2004Tornadoes in 2004

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.