Alert archive / Iowa / Tornado Warnings in 2002

Tornado Warning 11, NWS Des Moines, IA

April 18, 2002Decatur County, Ringgold County, Iowa

NWS Des Moines, IA issued this tornado warning at Apr 18, 2002, 7:24 PM CDT for Decatur County, Ringgold County, Iowa. It was in force for 51 min. 2 reports came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued: Apr 18, 2002, 7:24 PM CDT (00:24 UTC)
Expired: Apr 18, 2002, 8:15 PM CDT
In force: 51 min
Issued by: NWS Des Moines, IA
Area: Counties, with a storm outline in the text

Counties Decatur County, IA, Ringgold County, IA

The radar

The Des Moines radar (KDMX), 119 km from the middle of the area, began a volume at 00:25 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.

What was reported inside it

Time	Report	Where	Remark
Apr 18, 7:50 PM CDT	Hail 1	Lamoni, IA
Apr 18, 8:00 PM CDT	Hail 1	Decatur City, IA

NCEI Storm Data entries that began inside the alert's area while it was in force. Before 2003 the local storm report archive is thin, so this is the record of what happened rather than what was phoned in.

The watch it was issued in

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

Issued	Product	Office	Lasted
Apr 18, 4:15 PM CDT	Tornado Watch	SPC	5 hr

The nearest sounding before it

Omaha, NE (KOAX), launched 00:00Z, 0.4 hours before the alert went out and 211 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 3349 m above ground
0-6 km bulk shear: 46 kt
0-1 km storm-relative helicity: 1 m²/s²
0-3 km storm-relative helicity: 148 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

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

000 
WFUS53 KDMX 190024
TORDSM
IAC053-159-190115-

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE DES MOINES IA
724 PM CDT THU APR 18 2002

THE NATIONAL WEATHER SERVICE IN DES MOINES HAS ISSUED A

* TORNADO WARNING FOR...
  SOUTHERN DECATUR COUNTY IN SOUTH CENTRAL IOWA
  SOUTHEASTERN RINGGOLD COUNTY IN SOUTH CENTRAL IOWA

* UNTIL 815 PM CDT

* AT 721 PM...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  TORNADO 10 MILES WEST OF LAMONI...OR ABOUT 69 MILES SOUTH OF DES
  MOINES...MOVING EAST AT 20 MPH.

* THE TORNADO WILL BE...

  3 MILES NORTH OF LAMONI AROUND 750 PM AND
  6 MILES SOUTH OF LEON AROUND 815 PM.

IF IN MOBILE HOME OR NON-MOVING VEHICLE...EVACUATE AND GO TO A
SUBSTANTIAL SHELTER.

A TORNADO WATCH REMAINS IN EFFECT UNTIL 900 PM THURSDAY EVENING FOR
IOWA. LAT...LON 4075 9422 4057 9422 4054 9368 4078 9368

KULA/FORSTER

The office that day

Everything else NWS Des Moines, IA issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Apr 18, 7:02 PM CDT	Severe Thunderstorm Warning	DMX	Jasper	58 min
Apr 18, 7:04 PM CDT	Severe Thunderstorm Warning	DMX	Marshall	26 min
Apr 18, 7:04 PM CDT	Tornado Warning	DMX	Jasper	56 min
Apr 18, 7:10 PM CDT	Tornado Warning	DMX	Black Hawk	50 min
Apr 18, 7:38 PM CDT	Severe Thunderstorm Warning	DMX	Jasper, Marion	52 min
Apr 18, 7:57 PM CDT	Severe Thunderstorm Warning	DMX	Warren	33 min
Apr 18, 8:11 PM CDT	Severe Thunderstorm Warning	DMX	Poweshiek	64 min
Apr 18, 9:10 PM CDT	Severe Thunderstorm Warning	DMX	Mahaska	50 min

Nearby

Tornado Warnings in Iowa, 2002 Every tornado warning in 2002 Tornadoes in 2002

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.