Alert archive / Iowa / Severe Thunderstorm Warnings in 1998

Severe Thunderstorm Warning 138, NWS Des Moines, IA

May 28, 1998Webster County, Iowa

NWS Des Moines, IA issued this severe thunderstorm warning at May 28, 1998, 9:29 PM CDT for Webster County, Iowa. It was in force for 36 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, 9:29 PM CDT (02:29 UTC)
Expired
May 28, 1998, 10:05 PM CDT
In force
36 min
Issued by
NWS Des Moines, IA
Area
Whole counties

County Webster County, IA

The radar

The Des Moines radar (KDMX), 86 km from the middle of the area, began a volume at 02:32 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 28, 8:45 PM CDTTornado WatchSPC6 hr

The nearest sounding before it

Omaha, NE (KOAX), launched 00:00Z, 2.5 hours before the alert went out and 219 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 00:00Z on 1998-05-29Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2835 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 00:00Z on 1998-05-29The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 64 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
2835 J/kg
Mixed-layer CIN
-9 J/kg
Mixed-layer LCL
1954 m above ground
0-6 km bulk shear
39 kt
0-1 km storm-relative helicity
64 m²/s²
0-3 km storm-relative helicity
115 m²/s²
Significant tornado parameter
0.1
Supercell composite
7.5

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KDSM 290229 RRA
SVRDSM
IAC187-290305-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE DES MOINES IA
929 PM CDT THU MAY 28 1998

THE NATIONAL WEATHER SERVICE IN DES MOINES HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  SOUTHERN WEBSTER COUNTY IN CENTRAL IOWA

* UNTIL 1005 PM CDT

* AT 928 PM CDT... LOCAL LAW ENFORCEMENT REPORTED A SEVERE
  THUNDERSTORM 16 MILES SOUTH OF FORT DODGE OR 2 MILES WEST OF
  DAYTON MOVING EAST AT 30 MPH.

* THIS STORM CAN BE EXPECTED NEAR...
   DAYTON             BY 936 PM CDT

GO INSIDE A STURDY BUILDING AND STAY AWAY FROM WINDOWS! A TORNADO
WATCH IS IN EFFECT. SEVERE THUNDERSTORMS CAN AND OCCASIONALLY DO
PRODUCE TORNADOES WITH LITTLE OR NO ADVANCE WARNING.

STARK

What forecasters said that day

The local office's own words before this severe thunderstorm warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

In the hours before

Special weather statement, May 28, 7:49 PM CDT, 1 hour 40 minutes before
IAZ004>007-015>017-023>028-033>039-044>050-057>062-070>075-081>086-
092>097-291100-

CENTRAL IOWA THUNDERSTORM OUTLOOK
NATIONAL WEATHER SERVICE DES MOINES IA
749 PM CDT THU MAY 28 1998

HAZARD--SCATTERED THUNDERSTORMS...SOME POSSIBLY SEVERE AND CAPABLE OF
PRODUCING ISOLATED TORNADOES...LARGE HAIL AND DAMAGING WINDS.
LOCALLY HEAVY RAINFALL IS ALSO POSSIBLE WITH SOME AREAS SEEING
BETWEEN 1 AND 3 INCHES OF RAIN IN A SHORT TIME.

AREAS OF CONCERN AND TIMING DETAILS--THROUGH 9 PM THE THREAT OF
SEVERE WEATHER WILL BE OVER THE NORTHERN HALF OF IOWA...MAINLY ALONG
AND NORTH OF HIGHWAY 20.  AFTER 9 PM THE THREAT OF SEVERE WEATHER
WILL SHIFT INTO AREAS FARTHER SOUTH...MAINLY SOUTH OF HIGHWAY 20 AND
NORTH OF HIGHWAY 92.  ADDITIONAL WATCHES MAY BE ISSUED IN IOWA THIS
EVENING.

METEOROLOGICAL COMMENTS--A COLD FRONT REMAINS ACROSS THE NORTHERN
THIRD OF IOWA THIS EVENING.  MOISTURE CONTINUES TO POOL ALONG THIS
BOUNDARY WITH DEW POINTS IN THE MID 60S TO LOWER 70S ACROSS THE
STATE.  THE ATMOSPHERE REMAINS VERY UNSTABLE WITH LIFTED INDICES IN
THE -6 TO -10 RANGE.  THIS INSTABILITY INDICATES THE POTENTIAL FOR
ISOLATED TORNADOES AND SEVERE STORMS.  THE FIRST ROUND OF STORMS THAT
DEVELOPED ALONG THE FRONTAL BOUNDARY LATE THIS AFTERNOON PRODUCED AN
OUTFLOW BOUNDARY THAT MOVED SOUTH INTO CENTRAL IOWA AND EXTENDS BACK
INTO NORTHWEST IOWA WHERE ADDITIONAL THUNDERSTORMS HAVE DEVELOPED.
SCATTERED THUNDERSTORMS WILL CONTINUE TO DEVELOP ALONG THIS BOUNDARY
TONIGHT.

PRECAUTIONS--EMERGENCY MANAGERS AND SPOTTERS SHOULD CONTINUE TO
MONITOR THE WEATHER SITUATION THIS EVENING.  DEPLOYMENT OF SPOTTERS
IN CENTRAL IOWA MAY BE NEEDED AFTER 9 PM OR SO.  CONDITIONS REMAIN
FAVORABLE THIS EVENING FOR SEVERE THUNDERSTORMS AND VERY HEAVY
RAINFALL.

STARK
Special weather statement, May 28, 7:49 PM CDT, 1 hour 40 minutes before
IAZ004>007-015>017-023>028-033>039-044>050-057>062-070>075-081>086-
092>097-291100-

CENTRAL IOWA THUNDERSTORM OUTLOOK
NATIONAL WEATHER SERVICE DES MOINES IA
749 PM CDT THU MAY 28 1998

HAZARD--SCATTERED THUNDERSTORMS...SOME POSSIBLY SEVERE AND CAPABLE OF
PRODUCING ISOLATED TORNADOES...LARGE HAIL AND DAMAGING WINDS.
LOCALLY HEAVY RAINFALL IS ALSO POSSIBLE WITH SOME AREAS SEEING
BETWEEN 1 AND 3 INCHES OF RAIN IN A SHORT TIME.

AREAS OF CONCERN AND TIMING DETAILS--THROUGH 9 PM THE THREAT OF
SEVERE WEATHER WILL BE OVER THE NORTHERN HALF OF IOWA...MAINLY ALONG
AND NORTH OF HIGHWAY 20.  AFTER 9 PM THE THREAT OF SEVERE WEATHER
WILL SHIFT INTO AREAS FARTHER SOUTH...MAINLY SOUTH OF HIGHWAY 20 AND
NORTH OF HIGHWAY 92.  ADDITIONAL WATCHES MAY BE ISSUED IN IOWA THIS
EVENING.

METEOROLOGICAL COMMENTS--A COLD FRONT REMAINS ACROSS THE NORTHERN
THIRD OF IOWA THIS EVENING.  MOISTURE CONTINUES TO POOL ALONG THIS
BOUNDARY WITH DEW POINTS IN THE MID 60S TO LOWER 70S ACROSS THE
STATE.  THE ATMOSPHERE REMAINS VERY UNSTABLE WITH LIFTED INDICES IN
THE -6 TO -10 RANGE.  THIS INSTABILITY INDICATES THE POTENTIAL FOR
ISOLATED TORNADOES AND SEVERE STORMS.  THE FIRST ROUND OF STORMS THAT
DEVELOPED ALONG THE FRONTAL BOUNDARY LATE THIS AFTERNOON PRODUCED AN
OUTFLOW BOUNDARY THAT MOVED SOUTH INTO CENTRAL IOWA AND EXTENDS BACK
INTO NORTHWEST IOWA WHERE ADDITIONAL THUNDERSTORMS HAVE DEVELOPED.
SCATTERED THUNDERSTORMS WILL CONTINUE TO DEVELOP ALONG THIS BOUNDARY
TONIGHT.

PRECAUTIONS--EMERGENCY MANAGERS AND SPOTTERS SHOULD CONTINUE TO
MONITOR THE WEATHER SITUATION THIS EVENING.  DEPLOYMENT OF SPOTTERS
IN CENTRAL IOWA MAY BE NEEDED AFTER 9 PM OR SO.  CONDITIONS REMAIN
FAVORABLE THIS EVENING FOR SEVERE THUNDERSTORMS AND VERY HEAVY
RAINFALL.

STARK
Local storm report, May 28, 8:39 PM CDT, 50 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE DES MOINES IA
839 PM CDT THU MAY 28 1998

TIME(CDT)  .....CITY LOCATION..... STATE  ...EVENT/REMARKS...
           ....COUNTY LOCATION....

0340 PM    POCAHONTAS                IA   TORNADO
05/28/98   POCAHONTAS                     TORNADO 6 MILES NORTHWEST
                                          OF POCAHANTAS

0523 PM    RADCLIFFE                 IA   WIND DAMAGE
05/28/98   HARDIN                         SHINGLES BLOWN OFF ROOF

0542 PM    GRUNDY CENTER             IA   70 MPH TSTM GUST
05/28/98   GRUNDY                         JUST NORTH OF GRUNDY
                                          CENTER

0553 PM    BADGER                    IA   1.75 INCH HAIL
05/28/98   WEBSTER

The office that day

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

IssuedProductOfficeCountiesLasted
May 28, 8:20 PM CDTSevere Thunderstorm WarningDMXSac20 min
May 28, 8:24 PM CDTSevere Thunderstorm WarningDMXCalhoun36 min
May 28, 8:57 PM CDTSevere Thunderstorm WarningDMXCalhoun, Webster33 min
May 28, 9:22 PM CDTTornado WarningDMXCrawford33 min
May 28, 9:41 PM CDTSevere Thunderstorm WarningDMXBoone34 min
May 28, 9:52 PM CDTTornado WarningDMXCrawford33 min
May 28, 10:15 PM CDTSevere Thunderstorm WarningDMXStory50 min
May 28, 10:21 PM CDTTornado WarningDMXCarroll, Crawford39 min
May 28, 10:21 PM CDTTornado WarningDMXCarroll, Crawford34 min
May 28, 10:40 PM CDTSevere Thunderstorm WarningDMXMarshall50 min
May 28, 10:46 PM CDTSevere Thunderstorm WarningDMXCrawford34 min
May 28, 10:50 PM CDTSevere Thunderstorm WarningDMXCarroll35 min
May 28, 11:04 PM CDTTornado WarningDMXCarroll36 min
May 28, 11:10 PM CDTTornado WarningDMXAudubon35 min
May 28, 11:25 PM CDTTornado WarningDMXGreene, Guthrie35 min
May 28, 11:44 PM CDTTornado WarningDMXAudubon, Guthrie36 min
May 28, 11:59 PM CDTTornado WarningDMXDallas, Guthrie51 min
May 29, 12:09 AM CDTSevere Thunderstorm WarningDMXAudubon36 min
May 29, 12:24 AM CDTTornado WarningDMXGuthrie26 min
May 29, 12:33 AM CDTSevere Thunderstorm WarningDMXCass32 min
May 29, 12:50 AM CDTSevere Thunderstorm WarningDMXAdair, Dallas, Guthrie50 min
May 29, 1:24 AM CDTSevere Thunderstorm WarningDMXCass31 min
May 29, 2:01 AM CDTSevere Thunderstorm WarningDMXAdams34 min
May 29, 2:01 AM CDTSevere Thunderstorm WarningDMXAdams39 min
May 29, 2:21 AM CDTSevere Thunderstorm WarningDMXAdair, Union49 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.