Alert archive / Iowa / Severe Thunderstorm Warnings in 1998

Severe Thunderstorm Warning 92, NWS Des Moines, IA

May 20, 1998Jasper County, Marion County, Iowa

NWS Des Moines, IA issued this severe thunderstorm warning at May 20, 1998, 5:47 AM CDT for Jasper County, Marion County, Iowa. It was in force for 48 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 20, 1998, 5:47 AM CDT (10:47 UTC)
Expired
May 20, 1998, 6:35 AM CDT
In force
48 min
Issued by
NWS Des Moines, IA
Area
Whole counties

Counties Jasper County, IA, Marion County, IA

The radar

The Des Moines radar (KDMX), 59 km from the middle of the area, began a volume at 10:51 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
May 20, 1:45 AM CDTSevere Thunderstorm WatchSPC6 hr

The nearest sounding before it

Davenport, (KDVN), launched 00:00Z, 10.8 hours before the alert went out and 215 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 00:00Z on 1998-05-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 497 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 00:00Z on 1998-05-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 18 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
497 J/kg
Mixed-layer CIN
-160 J/kg
Mixed-layer LCL
1790 m above ground
0-6 km bulk shear
41 kt
0-1 km storm-relative helicity
18 m²/s²
0-3 km storm-relative helicity
206 m²/s²
Significant tornado parameter
0.0
Supercell composite
3.9

Open this sounding in Storm Lab

The text

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

923 
WUUS1 KDSM 201048
SVRDSM
IAC099-125-201135-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE DES MOINES IA
547 AM CDT WED MAY 20 1998

THE NATIONAL WEATHER SERVICE IN DES MOINES HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  JASPER COUNTY IN CENTRAL IOWA
  MARION COUNTY IN SOUTH CENTRAL IOWA

* UNTIL 635 AM CDT

* AT 546 AM CDT... DOPPLER RADAR INDICATED A LINE OF SEVERE
  THUNDERSTORMS 15 MILES EAST SOUTHEAST OF DES MOINES OR 8 MILES
  SOUTHWEST OF PRAIRE CITY MOVING EAST AT 40 MPH.

* THIS STORM CAN BE EXPECTED NEAR...
   PRAIRE CITY        BY 545 AM CDT
   COLFAX             BY 546 AM CDT
   MONROE             BY 554 AM CDT
   NEWTON             BY 601 AM CDT
   KNOXVILLE          BY 601 AM CDT
   PELLA              BY 606 AM CDT


DAMAGING WINDS AND HEAVY RAIN ARE LIKELY. GO INSIDE A STURDY
BUILDING AND STAY AWAY FROM WINDOWS

COGIL

The office that day

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

IssuedProductOfficeCountiesLasted
May 19, 7:23 PM CDTSevere Thunderstorm WarningDMXAppanoose47 min
May 19, 7:31 PM CDTSevere Thunderstorm WarningDMXWarren34 min
May 19, 7:59 PM CDTSevere Thunderstorm WarningDMXLucas36 min
May 20, 3:46 AM CDTSevere Thunderstorm WarningDMXCrawford49 min
May 20, 3:53 AM CDTSevere Thunderstorm WarningDMXAudubon, Cass62 min
May 20, 4:31 AM CDTSevere Thunderstorm WarningDMXCarroll49 min
May 20, 5:20 AM CDTSevere Thunderstorm WarningDMXDallas, Madison, Polk, Warren60 min
May 20, 10:19 AM CDTSevere Thunderstorm WarningDMXMarion36 min
May 20, 10:21 AM CDTSevere Thunderstorm WarningDMXMarion34 min
May 20, 10:50 AM CDTSevere Thunderstorm WarningDMXMonroe35 min
May 20, 11:05 AM CDTSevere Thunderstorm WarningDMXWapello35 min
May 20, 11:45 AM CDTSevere Thunderstorm WarningDMXMahaska20 min

Nearby

Severe Thunderstorm Warnings in Iowa, 1998Every severe thunderstorm warning 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.