Alert archive / Iowa / Tornado Warnings in 1997

Tornado Warning 15, NWS Quad Cities, IA

May 18, 1997Linn County, Iowa

NWS Quad Cities, IA issued this tornado warning at May 18, 1997, 4:46 PM CDT for Linn County, Iowa. It was in force for 49 min. 1 report came from inside the area while it was in force.

The area

The counties it named, with what was reported inside it.

The facts

Issued: May 18, 1997, 4:46 PM CDT (21:46 UTC)
Expired: May 18, 1997, 5:35 PM CDT
In force: 49 min
Issued by: NWS Quad Cities, IA
Area: Whole counties

County Linn County, IA

The radar

The Quad Cities radar (KDVN), 99 km from the middle of the area, began a volume at 21:48 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
May 18, 5:30 PM CDT	Thunderstorm Wind 65	Mt Vernon, IA	New grain bin destroyed and several old outbuildings damaged.

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
May 18, 2:30 PM CDT	Tornado Watch	SPC	7 hr

The nearest sounding before it

Davenport, (KDVN), launched 12:00Z, 9.8 hours before the alert went out and 104 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: 1986 m above ground
0-6 km bulk shear: 43 kt
0-1 km storm-relative helicity: 266 m²/s²
0-3 km storm-relative helicity: 293 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.

865 
WFUS1 KMLI 182145 RRA
TORMLI
IAC113-182235-

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
446 PM CDT SUN MAY 18 1997

* TORNADO WARNING FOR
  LINN COUNTY - IN EAST CENTRAL IOWA

* UNTIL 535 PM CDT
 
* THIS TORNADO WILL REACH NEAR
  BERTRAM                            AROUND 445 PM CDT
  MARION AIRPORT                     AROUND 445 PM CDT
  WEIR                               AROUND 445 PM CDT
  IVANHOE                            AROUND 450 PM CDT
  WHITTIER                           AROUND 450 PM CDT

* AT 446 PM CDT...A DEVELOPING TORNADO WAS INDICATED BY QUAD CITIES
  IA DOPPLER RADAR IN THE VICINITY OF CEDAR RAPIDS MOVING EAST AT 35
  MPH.
 
IF YOU ARE OUTSIDE...SEEK SHELTER IN A NEARBY REINFORCED
BUILDING. AS A LAST RESORT...GO TO A CULVERT...DITCH OR LOW SPOT
AND COVER YOUR HEAD WITH YOUR HANDS.

PIERCE

The office that day

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

Issued	Product	Office	Counties	Lasted
May 18, 3:10 PM CDT	Severe Thunderstorm Warning	DVN	Benton	50 min
May 18, 3:35 PM CDT	Severe Thunderstorm Warning	DVN	Linn	50 min
May 18, 3:55 PM CDT	Tornado Warning	DVN	Benton, Linn	50 min
May 18, 4:19 PM CDT	Severe Thunderstorm Warning	DVN	Delaware	51 min
May 18, 4:30 PM CDT	Tornado Warning	DVN	Cedar, Jones	50 min
May 18, 4:45 PM CDT	Tornado Warning	DVN	Benton	50 min
May 18, 4:51 PM CDT	Severe Thunderstorm Warning	DVN	Dubuque	49 min
May 18, 5:08 PM CDT	Severe Thunderstorm Warning	DVN	Clinton, Jackson	47 min
May 18, 5:11 PM CDT	Flash Flood Warning	DVN	Benton, Linn	3 hr
May 18, 5:18 PM CDT	Severe Thunderstorm Warning	DVN	Cedar, Jones	47 min
May 18, 5:32 PM CDT	Severe Thunderstorm Warning	DVN	Iowa, Johnson	63 min
May 18, 5:36 PM CDT	Severe Thunderstorm Warning	DVN	Linn	49 min
May 18, 5:36 PM CDT	Severe Thunderstorm Warning	DVN	Dubuque	49 min
May 18, 5:49 PM CDT	Severe Thunderstorm Warning	DVN	Clinton	46 min
May 18, 5:53 PM CDT	Severe Thunderstorm Warning	DVN	Delaware	47 min
May 18, 6:20 PM CDT	Severe Thunderstorm Warning	DVN	Dubuque	50 min
May 18, 6:28 PM CDT	Flash Flood Warning	DVN	Dubuque	3 hr
May 18, 6:31 PM CDT	Tornado Warning	DVN	Johnson	49 min
May 18, 6:55 PM CDT	Tornado Warning	DVN	Cedar, Muscatine	50 min

Nearby

Tornado Warnings in Iowa, 1997 Every tornado warning in 1997 Tornadoes in 1997

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.