Alert archive / Iowa / Tornado Warnings in 2004

Tornado Warning 11, NWS Quad Cities, IA

May 21, 2004Clinton County, Jackson County, Iowa

NWS Quad Cities, IA issued this tornado warning at May 21, 2004, 5:38 PM CDT for Clinton County, Jackson County, Iowa. It was in force for 67 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: May 21, 2004, 5:38 PM CDT (22:38 UTC)
Expired: May 21, 2004, 6:45 PM CDT
In force: 67 min
Issued by: NWS Quad Cities, IA
Area: Counties, with a storm outline in the text

Counties Clinton County, IA, Jackson County, IA

The radar

The Quad Cities radar (KDVN), 50 km from the middle of the area, began a volume at 22:41 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
May 21, 2:45 PM CDT	Tornado Watch	SPC	7 hr

The nearest sounding before it

Lincoln, IL (KILX), launched 12:00Z, 10.6 hours before the alert went out and 271 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: 2541 J/kg
Mixed-layer CIN: -64 J/kg
Mixed-layer LCL: 923 m above ground
0-6 km bulk shear: 29 kt
0-1 km storm-relative helicity: 59 m²/s²
0-3 km storm-relative helicity: 99 m²/s²
Significant tornado parameter: 0.5
Supercell composite: 3.0

Open this sounding in Storm Lab

The text

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

750 
WFUS53 KDVN 212238
TORDVN
IAC045-097-212345-

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
538 PM CDT FRI MAY 21 2004

THE NATIONAL WEATHER SERVICE IN THE QUAD CITIES HAS ISSUED A

* TORNADO WARNING FOR...
  NORTHERN CLINTON COUNTY IN EAST CENTRAL IOWA
  JACKSON COUNTY IN EAST CENTRAL IOWA

* UNTIL 645 PM CDT

* AT 531 PM CDT...TRAINED SPOTTERS REPORTED A TORNADO 11 MILES
  SOUTHWEST OF MONMOUTH...OR ABOUT 12 MILES SOUTHEAST OF ANAMOSA...
  MOVING EAST AT 30 MPH.

* THE TORNADO IS EXPECTED TO BE NEAR...
  MONMOUTH BY 545 PM CDT
  LOST NATION BY 550 PM CDT
  NASHVILLE BY 555 PM CDT
  HURSTVILLE BY 600 PM CDT
  MAQUOKETA BY 605 PM CDT
  DELMAR BY 610 PM CDT

HEAVY RAIN MAY OBSCURE THE APPROACH OF THE TORNADO. TAKE SHELTER NOW

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


LAT...LON 4196 9064 4197 9090 4214 9088 4221 9061
          4224 9044 4195 9017

$$

ERVIN

The office that day

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

Issued	Product	Office	Counties	Lasted
May 20, 7:13 PM CDT	Severe Thunderstorm Warning	DVN	Johnson, Washington	62 min
May 20, 7:41 PM CDT	Severe Thunderstorm Warning	DVN	Louisa	64 min
May 20, 7:54 PM CDT	Severe Thunderstorm Warning	DVN	Cedar	66 min
May 21, 6:28 AM CDT	Severe Thunderstorm Warning	DVN	Buchanan, Delaware	62 min
May 21, 3:26 PM CDT	Tornado Warning	DVN	Buchanan	64 min
May 21, 3:27 PM CDT	Severe Thunderstorm Warning	DVN	Benton	48 min
May 21, 3:38 PM CDT	Tornado Warning	DVN	Benton	37 min
May 21, 4:12 PM CDT	Tornado Warning	DVN	Linn	63 min
May 21, 4:14 PM CDT	Tornado Warning	DVN	Benton	31 min
May 21, 4:43 PM CDT	Flash Flood Warning	DVN	Benton, Buchanan, Delaware, Linn	6 hr
May 21, 4:44 PM CDT	Severe Thunderstorm Warning	DVN	Benton	61 min
May 21, 4:48 PM CDT	Tornado Warning	DVN	Benton	57 min
May 21, 4:51 PM CDT	Severe Thunderstorm Warning	DVN	Delaware	54 min
May 21, 5:05 PM CDT	Tornado Warning	DVN	Jones	55 min
May 21, 5:21 PM CDT	Severe Thunderstorm Warning	DVN	Linn	54 min
May 21, 5:51 PM CDT	Flash Flood Warning	DVN	Jones	6 hr
May 21, 5:56 PM CDT	Severe Thunderstorm Warning	DVN	Cedar, Jones	64 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.