Alert archive / Iowa / Tornado Warnings in 1998

Tornado Warning 49, NWS Quad Cities, IA

June 29, 1998Johnson County, Iowa

NWS Quad Cities, IA issued this tornado warning at Jun 29, 1998, 2:53 PM CDT for Johnson County, Iowa. It was in force for 62 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued
Jun 29, 1998, 2:53 PM CDT (19:53 UTC)
Expired
Jun 29, 1998, 3:55 PM CDT
In force
62 min
Issued by
NWS Quad Cities, IA
Area
Whole counties

County Johnson County, IA

The radar

The Quad Cities radar (KDVN), 84 km from the middle of the area, began a volume at 19:55 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.

The watch it was issued in

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

IssuedProductOfficeLasted
Jun 29, 1:00 PM CDTTornado WatchSPC4 hr

The nearest sounding before it

Davenport, (KDVN), launched 12:00Z, 7.9 hours before the alert went out and 91 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-pSkew-T log-p diagram, Davenport, at 12:00Z on 1998-06-29Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 917 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Davenport, at 12:00Z on 1998-06-29The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 87 square meters per square second.1939587897117136Sfc1 km3 km6 km9 kmRMLM
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
917 J/kg
Mixed-layer CIN
-115 J/kg
Mixed-layer LCL
762 m above ground
0-6 km bulk shear
28 kt
0-1 km storm-relative helicity
87 m²/s²
0-3 km storm-relative helicity
11 m²/s²
Significant tornado parameter
0.1
Supercell composite
1.5

Open this sounding in Storm Lab

The text

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

337 
WFUS1 KMLI 291955
TORMLI
IAC103-292055-

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
253 PM CDT MON JUN 29 1998

THE NATIONAL WEATHER SERVICE IN QUAD CITIES IA HAS ISSUED A

* TORNADO WARNING FOR...
  JOHNSON COUNTY IN EAST CENTRAL IOWA

* UNTIL 355 PM CDT

* AT 254 PM CDT... DOPPLER RADAR INDICATED A DEVELOPING TORNADO 8
  MILES WEST OF IOWA CITY OR 4 MILES WEST OF OAKDALE MOVING EAST AT
  35 MPH.

* THE TORNADO IS EXPECTED TO BE NEAR...
  NORTH LIBERTY                              AROUND 300 PM CDT
  OAKDALE                                    AROUND 300 PM CDT
  TWIN VIEW HGTS                             AROUND 300 PM CDT
  CORALVILLE                                 AROUND 300 PM CDT
  IOWA CITY                                  AROUND 305 PM CDT

GO TO THE BASEMENT OR A SMALL INTERIOR ROOM ON THE LOWEST FLOOR

BERG

The office that day

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

IssuedProductOfficeCountiesLasted
Jun 29, 1:53 PM CDTSevere Thunderstorm WarningDVNBenton, Iowa62 min
Jun 29, 2:11 PM CDTSevere Thunderstorm WarningDVNKeokuk64 min
Jun 29, 2:24 PM CDTTornado WarningDVNBenton, Iowa36 min
Jun 29, 2:30 PM CDTSevere Thunderstorm WarningDVNJohnson, Linn65 min
Jun 29, 2:42 PM CDTTornado WarningDVNKeokuk33 min
Jun 29, 2:46 PM CDTSevere Thunderstorm WarningDVNJefferson, Washington64 min
Jun 29, 2:55 PM CDTTornado WarningDVNWashington65 min
Jun 29, 3:07 PM CDTTornado WarningDVNCedar, Muscatine63 min
Jun 29, 3:07 PM CDTTornado WarningDVNHenry, Louisa63 min
Jun 29, 3:07 PM CDTTornado WarningDVNVan Buren63 min
Jun 29, 3:22 PM CDTTornado WarningDVNDes Moines, Lee63 min
Jun 29, 3:26 PM CDTSevere Thunderstorm WarningDVNClinton, Scott64 min
Jun 29, 6:03 PM CDTTornado WarningDVNLee62 min

Nearby

Tornado Warnings in Iowa, 1998Every tornado warning in 1998Tornadoes in 1998

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.