Alert archive / Iowa / Tornado Warnings in 2002

Tornado Warning 19, NWS Des Moines, IA

June 20, 2002Crawford County, Iowa

NWS Des Moines, IA issued this tornado warning at Jun 20, 2002, 9:54 PM CDT for Crawford County, Iowa. It was in force for 51 min. 1 report 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: Jun 20, 2002, 9:54 PM CDT (02:54 UTC)
Expired: Jun 20, 2002, 10:45 PM CDT
In force: 51 min
Issued by: NWS Des Moines, IA
Area: Counties, with a storm outline in the text

County Crawford County, IA

The radar

The Omaha radar (KOAX), 116 km from the middle of the area, began a volume at 02:55 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
Jun 20, 10:15 PM CDT	Hail 0.75	Denison, 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
Jun 20, 4:00 PM CDT	Tornado Watch	SPC	6 hr

The nearest sounding before it

Omaha, NE (KOAX), launched 00:00Z, 2.9 hours before the alert went out and 116 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: 1337 J/kg
Mixed-layer CIN: -10 J/kg
Mixed-layer LCL: 1609 m above ground
0-6 km bulk shear: 37 kt
0-1 km storm-relative helicity: 25 m²/s²
0-3 km storm-relative helicity: 96 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.6

Open this sounding in Storm Lab

The text

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

000 
WFUS53 KDMX 210254
TORDSM
IAC047-210345-

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE DES MOINES IA
954 PM CDT THU JUN 20 2002

THE NATIONAL WEATHER SERVICE IN DES MOINES HAS ISSUED A

* TORNADO WARNING FOR...
  CRAWFORD COUNTY IN WEST CENTRAL IOWA

* UNTIL 1045 PM CDT

* AT 952 PM...RADAR INDICATED A THUNDERSTORM CAPABLE OF PRODUCING A
  TORNADO 3 MILES NORTHEAST OF ARION...OR ABOUT 55 MILES NORTHEAST OF
  COUNCIL BLUFFS...MOVING NORTHEAST AT 20 MPH.

* THE STORM WILL BE...

  NEAR DENISON AROUND 1005 PM...
  NEAR DELOIT AROUND 1020 PM AND
  4 MILES NORTHWEST OF VAIL AROUND 1025 PM.

THIS WARNING REPLACES THE SEVERE THUNDERSTORM WARNING PREVIOUSLY
ISSUED FOR THE WARNED AREA.

THIS IS A HAZARDOUS SITUATION. SEEK SHELTER IN A BASEMENT...OR IN AN
INTERIOR ROOM. STAY AWAY FROM WINDOWS. IF YOU ARE OUTSIDE OR IN A
CAR...SEEK SHELTER IN A REINFORCED BUILDING.

A TORNADO WATCH REMAINS IN EFFECT UNTIL 1000 PM THURSDAY EVENING FOR
SOUTHWESTERN IOWA.

LAT...LON 4219 9558 4187 9560 4190 9512 4218 9511

JOHNSON

The office that day

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

Issued	Product	Office	Counties	Lasted
Jun 20, 7:21 PM CDT	Severe Thunderstorm Warning	DMX	Story	54 min
Jun 20, 8:05 PM CDT	Severe Thunderstorm Warning	DMX	Calhoun, Webster	55 min
Jun 20, 8:30 PM CDT	Tornado Warning	DMX	Webster	45 min
Jun 20, 8:32 PM CDT	Tornado Warning	DMX	Webster	43 min
Jun 20, 9:23 PM CDT	Severe Thunderstorm Warning	DMX	Webster	47 min
Jun 20, 9:40 PM CDT	Severe Thunderstorm Warning	DMX	Crawford	50 min
Jun 20, 10:53 PM CDT	Severe Thunderstorm Warning	DMX	Webster	52 min
Jun 21, 1:07 PM CDT	Severe Thunderstorm Warning	DMX	Cerro Gordo	38 min
Jun 21, 1:22 PM CDT	Tornado Warning	DMX	Butler	53 min
Jun 21, 2:13 PM CDT	Tornado Warning	DMX	Butler	32 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.