Alert archive / Iowa / Tornado Warnings in 1998

Tornado Warning 18, NWS Des Moines, IA

May 28, 1998Pocahontas County, Iowa

NWS Des Moines, IA issued this tornado warning at May 28, 1998, 3:49 PM CDT for Pocahontas County, Iowa. It was in force for 31 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 28, 1998, 3:49 PM CDT (20:49 UTC)
Expired
May 28, 1998, 4:20 PM CDT
In force
31 min
Issued by
NWS Des Moines, IA
Area
Whole counties

County Pocahontas County, IA

The watch it was issued in

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

IssuedProductOfficeLasted
May 28, 3:00 PM CDTSevere Thunderstorm WatchSPC5 hr

The nearest sounding before it

Omaha, NE (KOAX), launched 12:00Z, 8.8 hours before the alert went out and 210 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 1998-05-28Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1669 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 1998-05-28The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 242 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
1669 J/kg
Mixed-layer CIN
-237 J/kg
Mixed-layer LCL
991 m above ground
0-6 km bulk shear
23 kt
0-1 km storm-relative helicity
242 m²/s²
0-3 km storm-relative helicity
226 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.

943 
WFUS1 KDSM 282051 RRA
TORDSM
IAC151-282120-

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE DES MOINES IA
349 PM CDT THU MAY 28 1998

THE NATIONAL WEATHER SERVICE IN DES MOINES HAS ISSUED A

* TORNADO WARNING FOR...
  POCAHONTAS COUNTY IN NORTHWESTERN IOWA

* UNTIL 420 PM CDT

* AT 347 PM CDT... LOCAL LAW ENFORCEMENT REPORTED A TORNADO 56 MILES
  WEST OF DES MOINES MOVING EAST AT 25 MPH.

* THE TORNADO IS EXPECTED TO MOVE THROUGH
   POCHONTAS BY 4 PM CDT
   ROLFE BY 355 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 28, 3:14 PM CDTTornado WarningDMXPocahontas36 min
May 28, 3:26 PM CDTSevere Thunderstorm WarningDMXPalo Alto34 min
May 28, 4:08 PM CDTSevere Thunderstorm WarningDMXWebster37 min
May 28, 4:10 PM CDTSevere Thunderstorm WarningDMXHumboldt30 min
May 28, 4:25 PM CDTSevere Thunderstorm WarningDMXWright20 min
May 28, 4:28 PM CDTSevere Thunderstorm WarningDMXHamilton32 min
May 28, 4:44 PM CDTTornado WarningDMXWright21 min
May 28, 4:59 PM CDTSevere Thunderstorm WarningDMXHardin31 min
May 28, 5:26 PM CDTSevere Thunderstorm WarningDMXHardin34 min
May 28, 5:56 PM CDTSevere Thunderstorm WarningDMXHumboldt, Webster34 min
May 28, 6:01 PM CDTSevere Thunderstorm WarningDMXGrundy34 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.