Alert archive / Iowa / Tornado Warnings in 2004

Tornado Warning 47, NWS Quad Cities, IA

October 29, 2004Johnson County, Iowa

NWS Quad Cities, IA issued this tornado warning at Oct 29, 2004, 9:00 PM CDT for Johnson County, Iowa. It was in force for 45 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: Oct 29, 2004, 9:00 PM CDT (02:00 UTC)
Expired: Oct 29, 2004, 9:45 PM CDT
In force: 45 min
Issued by: NWS Quad Cities, IA
Area: Counties, with a storm outline in the text

County Johnson County, IA

The radar

The Quad Cities radar (KDVN), 78 km from the middle of the area, began a volume at 02:00 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 watch it was issued in

The SPC watch in force over the same counties when this warning went out.

Issued	Product	Office	Lasted
Oct 29, 6:30 PM CDT	Tornado Watch	SPC	6 hr

The nearest sounding before it

Davenport, (KDVN), launched 00:00Z, 2.0 hours before the alert went out and 84 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: 1017 J/kg
Mixed-layer CIN: -18 J/kg
Mixed-layer LCL: 1067 m above ground
0-6 km bulk shear: 51 kt
0-1 km storm-relative helicity: 206 m²/s²
0-3 km storm-relative helicity: 250 m²/s²
Significant tornado parameter: 1.2
Supercell composite: 5.8

Open this sounding in Storm Lab

The text

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

000 
WFUS53 KDVN 300200
TORDVN
IAC103-300245-

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
900 PM CDT FRI OCT 29 2004

THE NATIONAL WEATHER SERVICE IN THE QUAD CITIES HAS ISSUED A

* TORNADO WARNING FOR...
  EASTERN JOHNSON COUNTY IN EAST CENTRAL IOWA

* UNTIL 945 PM CDT

* AT 859 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED   
  A TORNADO 2 MILES SOUTHEAST OF IOWA CITY MOVING NORTHEAST AT 55    
  MPH.

* THE TORNADO IS EXPECTED TO BE NEAR...
  ELMIRA AND MORSE BY 905 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.

TORNADOES AT NIGHT ARE DIFFICULT TO SEE AND ARE ESPECIALLY DANGEROUS.

LAT...LON 4168 9164 4154 9146 4164 9139 4182 9142

$$

MCCLURE

The office that day

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

Issued	Product	Office	Counties	Lasted
Oct 29, 7:20 PM CDT	Tornado Warning	DVN	Benton, Iowa	55 min
Oct 29, 8:48 PM CDT	Severe Thunderstorm Warning	DVN	Johnson, Louisa, Muscatine, Washington	57 min
Oct 29, 9:12 PM CDT	Severe Thunderstorm Warning	DVN	Cedar	33 min
Oct 29, 9:15 PM CDT	Severe Thunderstorm Warning	DVN	Des Moines, Henry, Louisa	45 min
Oct 29, 9:28 PM CDT	Severe Thunderstorm Warning	DVN	Jones	32 min
Oct 29, 9:46 PM CDT	Severe Thunderstorm Warning	DVN	Clinton	44 min
Oct 29, 9:56 PM CDT	Severe Thunderstorm Warning	DVN	Muscatine	34 min
Oct 29, 10:07 PM CDT	Severe Thunderstorm Warning	DVN	Scott	53 min

Nearby

Tornado Warnings in Iowa, 2004 Every tornado warning in 2004 Tornadoes 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; radar from the NEXRAD Level II archive.