Alert archive / Iowa / Tornado Warnings in 1998

Tornado Warning 32, NWS Des Moines, IA

May 30, 1998Boone County, Iowa

NWS Des Moines, IA issued this tornado warning at May 30, 1998, 1:50 PM CDT for Boone County, Iowa. It was in force for 50 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
May 30, 1998, 1:50 PM CDT (18:50 UTC)
Expired
May 30, 1998, 2:40 PM CDT
In force
50 min
Issued by
NWS Des Moines, IA
Area
Whole counties

County Boone County, IA

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

Omaha, NE (KOAX), launched 12:00Z, 6.8 hours before the alert went out and 218 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 1998-05-30Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1795 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, Omaha, NE at 12:00Z on 1998-05-30The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 135 square meters per square second.193958Sfc1 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
1795 J/kg
Mixed-layer CIN
-289 J/kg
Mixed-layer LCL
852 m above ground
0-6 km bulk shear
45 kt
0-1 km storm-relative helicity
135 m²/s²
0-3 km storm-relative helicity
264 m²/s²
Significant tornado parameter
0.0
Supercell composite
-0.3

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KDSM 301850 RRA
TORDSM
IAC015-301940-

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

THE NATIONAL WEATHER SERVICE IN DES MOINES HAS ISSUED A

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

* UNTIL 240 PM CDT

* AT 148 PM CDT... DOPPLER RADAR INDICATED A TORNADO 34 MILES NORTH
  OF DES MOINES OR 22 MILES WEST OF BEAVER MOVING EAST SOUTHEAST AT
  40 MPH.

* THIS TORNADO CAN BE EXPECTED NEAR...
   BEAVER             BY 211 PM CDT

A TORNADO IS ON THE GROUND! GO TO THE BASEMENT! IF A BASEMENT IS
NOT AVAILABLE...GO TO A SMALL INTERIOR ROOM ON THE LOWEST FLOOR!

FAB

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, 2:12 PM CDTSevere Thunderstorm WarningDMXMarshall48 min
May 30, 2:20 PM CDTTornado WarningDMXMarshall50 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; the sounding from the Mesonet's radiosonde archive.