Alert archive / Iowa / Tornado Warnings in 1998

Tornado Warning 13, NWS Des Moines, IA

May 19, 1998Polk County, Iowa

NWS Des Moines, IA issued this tornado warning at May 19, 1998, 4:11 PM CDT for Polk County, Iowa. It was in force for 34 min. 2 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 19, 1998, 4:11 PM CDT (21:11 UTC)
Expired
May 19, 1998, 4:45 PM CDT
In force
34 min
Issued by
NWS Des Moines, IA
Area
Whole counties

County Polk County, IA

The radar

The Des Moines radar (KDMX), 13 km from the middle of the area, began a volume at 21:15 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

TimeReportWhereRemark
May 19, 4:15 PM CDTHail 1.75Ankeny, IA
May 19, 4:45 PM CDTTornado F0Runnells, IASmall tornado with brief touchdown

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 nearest sounding before it

Omaha, NE (KOAX), launched 12:00Z, 9.2 hours before the alert went out and 236 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, Omaha, NE at 12:00Z on 1998-05-19Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1590 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, Omaha, NE at 12:00Z on 1998-05-19The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -21 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
1590 J/kg
Mixed-layer CIN
-196 J/kg
Mixed-layer LCL
1416 m above ground
0-6 km bulk shear
23 kt
0-1 km storm-relative helicity
-21 m²/s²
0-3 km storm-relative helicity
16 m²/s²
Significant tornado parameter
0.0
Supercell composite
-0.2

Open this sounding in Storm Lab

The text

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

550 
WFUS1 KDSM 192112 RRA
TORDSM
IAC153-192145-

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE DES MOINES IA
411 PM CDT TUE MAY 19 1998

THE NATIONAL WEATHER SERVICE IN DES MOINES HAS ISSUED A

* TORNADO WARNING FOR...
  NORTHEASTERN POLK COUNTY IN CENTRAL IOWA

* UNTIL 445 PM CDT

* AT 410 PM CDT... DOPPLER RADAR INDICATED A TORNADO 10 MILES
  NORTHEAST OF DES MOINES OR 4 MILES WEST NORTHWEST OF MITCHELLVILLE
  MOVING SOUTHEAST AT 15 MPH.

* THIS TORNADO CAN BE EXPECTED NEAR...
   MITCHELLVILLE      BY 415 PM CDT
   ALTOONA            BY 417 PM CDT

IF YOU ARE IN A MULTIPLE STORY BUILDING...GO TO A SMALL INTERIOR
ROOM AWAY FROM WINDOWS.

FUNNEL CLOUDS HAVE BEEN REPORTED IN VICINITY OF I-80 AND ALTOONA.

JUNGBLUTH

The office that day

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

IssuedProductOfficeCountiesLasted
May 19, 3:09 PM CDTSevere Thunderstorm WarningDMXPolk, Warren31 min
May 19, 3:31 PM CDTSevere Thunderstorm WarningDMXPolk34 min
May 19, 3:56 PM CDTSevere Thunderstorm WarningDMXJasper34 min
May 19, 4:03 PM CDTSevere Thunderstorm WarningDMXPolk32 min
May 19, 4:23 PM CDTTornado WarningDMXJasper32 min
May 19, 4:34 PM CDTTornado WarningDMXMarion, Polk36 min
May 19, 4:44 PM CDTSevere Thunderstorm WarningDMXPoweshiek46 min
May 19, 4:49 PM CDTSevere Thunderstorm WarningDMXPolk46 min
May 19, 4:53 PM CDTTornado WarningDMXMarion32 min
May 19, 4:56 PM CDTSevere Thunderstorm WarningDMXJasper49 min
May 19, 5:11 PM CDTSevere Thunderstorm WarningDMXStory34 min
May 19, 5:24 PM CDTSevere Thunderstorm WarningDMXMarshall51 min
May 19, 5:27 PM CDTSevere Thunderstorm WarningDMXMarion33 min
May 19, 5:49 PM CDTSevere Thunderstorm WarningDMXPolk31 min
May 19, 6:02 PM CDTSevere Thunderstorm WarningDMXDallas, Warren33 min
May 19, 6:15 PM CDTSevere Thunderstorm WarningDMXPolk45 min
May 19, 6:24 PM CDTSevere Thunderstorm WarningDMXJasper, Marshall, Story31 min
May 19, 6:44 PM CDTSevere Thunderstorm WarningDMXWapello46 min
May 19, 6:57 PM CDTSevere Thunderstorm WarningDMXPolk48 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; radar from the NEXRAD Level II archive.