Alert archive / Iowa / Tornado Warnings in 1998

Tornado Warning 33, NWS Des Moines, IA

May 30, 1998Marshall County, Iowa

NWS Des Moines, IA issued this tornado warning at May 30, 1998, 2:20 PM CDT for Marshall County, Iowa. It was in force for 50 min. 5 reports 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 30, 1998, 2:20 PM CDT (19:20 UTC)
Expired
May 30, 1998, 3:10 PM CDT
In force
50 min
Issued by
NWS Des Moines, IA
Area
Whole counties

County Marshall County, IA

What was reported inside it

TimeReportWhereRemark
May 30, 2:25 PM CDTHail 1.75State Center, IA
May 30, 2:30 PM CDTTornado F1Rhodes, IAIntermittent path
May 30, 2:35 PM CDTHail 2.75State Center, IA
May 30, 2:38 PM CDTHail 1.75State Center, IA
May 30, 2:39 PM CDTHail 2.75State Center, 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.

IssuedProductOfficeLasted
May 30, 12:00 PM CDTSevere Thunderstorm WatchSPC5 hr
May 30, 1:00 PM CDTTornado WatchSPC4 hr

The nearest sounding before it

Davenport, (KDVN), launched 12:00Z, 7.3 hours before the alert went out and 212 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 1998-05-30Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 616 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Davenport, at 12:00Z on 1998-05-30The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 64 square meters per square second.19395878Sfc1 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
616 J/kg
Mixed-layer CIN
-69 J/kg
Mixed-layer LCL
1133 m above ground
0-6 km bulk shear
35 kt
0-1 km storm-relative helicity
64 m²/s²
0-3 km storm-relative helicity
3 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.9

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KDSM 301920 RRA
TORDSM
IAC127-302010-

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE DES MOINES IA
220 PM CDT SAT MAY 30 1998

THE NATIONAL WEATHER SERVICE IN DES MOINES HAS ISSUED A

* TORNADO WARNING FOR...
  MARSHALL COUNTY IN CENTRAL IOWA

* UNTIL 310 PM CDT

* AT 218 PM CDT... THE PUBLIC REPORTED A TORNADO 35 MILES NORTHEAST
  OF DES MOINES OR 6 MILES NORTHWEST OF MELBOURNE MOVING EAST
  SOUTHEAST AT 40 MPH.

* THIS TORNADO CAN BE EXPECTED NEAR...
   MELBOURNE          BY 216 PM CDT
   HAVERHILL          BY 226 PM CDT
   MARSHALLTOWN       BY 227 PM CDT
   LAUREL             BY 231 PM CDT
   FERGUSON           BY 233 PM CDT

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

THIS WARNING UPGRADES THE SEVERE THUNDERSTORM WARNING FOR MARSHALL
COUNTY.

TORNADOES ARE ON THE GROUND IN FAR EASTERN STORY COUNTY!!


SS

The office that day

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

IssuedProductOfficeCountiesLasted
May 30, 11:39 AM CDTSevere Thunderstorm WarningDMXSac51 min
May 30, 12:10 PM CDTSevere Thunderstorm WarningDMXCalhoun50 min
May 30, 12:38 PM CDTSevere Thunderstorm WarningDMXGreene, Webster47 min
May 30, 12:46 PM CDTTornado WarningDMXCalhoun, Greene34 min
May 30, 1:05 PM CDTSevere Thunderstorm WarningDMXBoone50 min
May 30, 1:25 PM CDTTornado WarningDMXBoone35 min
May 30, 1:34 PM CDTSevere Thunderstorm WarningDMXStory51 min
May 30, 1:50 PM CDTTornado WarningDMXBoone50 min
May 30, 2:12 PM CDTSevere Thunderstorm WarningDMXMarshall48 min
May 30, 2:52 PM CDTSevere Thunderstorm WarningDMXTama48 min
May 30, 3:08 PM CDTTornado WarningDMXMarshall22 min
May 30, 3:08 PM CDTTornado WarningDMXMarshall17 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; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive.