Alert archive / Iowa / Tornado Warnings in 2003

Tornado Warning 42, NWS Quad Cities, IA

July 20, 2003Linn County, Iowa

NWS Quad Cities, IA issued this tornado warning at Jul 20, 2003, 10:58 PM CDT for Linn County, Iowa. It was in force for 32 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: Jul 20, 2003, 10:58 PM CDT (03:58 UTC)
Expired: Jul 20, 2003, 11:30 PM CDT
In force: 32 min
Issued by: NWS Quad Cities, IA
Area: Counties, with a storm outline in the text

County Linn County, IA

The watch it was issued in

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

Issued	Product	Office	Lasted
Jul 20, 8:30 PM CDT	Tornado Watch	SPC	6 hr

The nearest sounding before it

Davenport, (KDVN), launched 00:00Z, 4.0 hours before the alert went out and 102 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: 3041 J/kg
Mixed-layer CIN: -67 J/kg
Mixed-layer LCL: 1003 m above ground
0-6 km bulk shear: 45 kt
0-1 km storm-relative helicity: 123 m²/s²
0-3 km storm-relative helicity: 251 m²/s²
Significant tornado parameter: 1.5
Supercell composite: 9.6

Open this sounding in Storm Lab

The text

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

174 
WFUS53 KDVN 210358
TORDVN
IAC113-210430-

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
1058 PM CDT SUN JUL 20 2003

THE NATIONAL WEATHER SERVICE IN THE QUAD CITIES HAS ISSUED A

* TORNADO WARNING FOR...
  SOUTHERN LINN COUNTY IN EAST CENTRAL IOWA

* UNTIL 1130 PM CDT

* AT 1052 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM WITH A POSSIBLE TORNADO OVER HIAWATHA...OR 6
  MILES NORTH OF CEDAR RAPIDS...MOVING SOUTHEAST AT 35 MPH.

* THE TORNADO IS EXPECTED TO BE NEAR...
   MARION BY 1100 PM CDT.
   MARION AIRPORT BY 1105 PM CDT.
   BERTRAM BY 1110 PM CDT.
   LISBON BY 1120 PM CDT.

NIGHTTIME TORNADOES ARE ESPECIALLY DANGEROUS BECAUSE THEY ARE
DIFFICULT TO SEE. TAKE COVER NOW

A TORNADO WATCH REMAINS IN EFFECT UNTIL 200 AM CDT MONDAY MORNING FOR
EASTERN IOWA AND NORTHWEST ILLINOIS.

LAT...LON 4216 9171 4200 9181 4185 9138 4208 9136

$$

DLF

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 20, 9:59 PM CDT	Severe Thunderstorm Warning	DVN	Benton, Buchanan, Linn	31 min
Jul 20, 10:27 PM CDT	Tornado Warning	DVN	Benton, Buchanan, Linn	33 min
Jul 20, 11:07 PM CDT	Tornado Warning	DVN	Cedar, Jones	23 min
Jul 20, 11:29 PM CDT	Tornado Warning	DVN	Cedar, Linn	31 min
Jul 20, 11:35 PM CDT	Tornado Warning	DVN	Jones	25 min
Jul 20, 11:43 PM CDT	Severe Thunderstorm Warning	DVN	Iowa, Johnson, Keokuk, Washington	47 min
Jul 20, 11:58 PM CDT	Severe Thunderstorm Warning	DVN	Louisa, Muscatine	32 min
Jul 21, 12:17 AM CDT	Severe Thunderstorm Warning	DVN	Scott	43 min
Jul 21, 12:30 AM CDT	Severe Thunderstorm Warning	DVN	Des Moines, Henry, Jefferson, Louisa, Washington	45 min

Nearby

Tornado Warnings in Iowa, 2003 Every tornado warning in 2003 Tornadoes in 2003

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.