Alert archive / Iowa / Tornado Warnings in 1998

Tornado Warning 61, NWS Des Moines, IA

August 24, 1998Palo Alto County, Iowa

NWS Des Moines, IA issued this tornado warning at Aug 24, 1998, 8:20 AM CDT for Palo Alto County, Iowa. It was in force for 35 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
Aug 24, 1998, 8:20 AM CDT (13:20 UTC)
Expired
Aug 24, 1998, 8:55 AM CDT
In force
35 min
Issued by
NWS Des Moines, IA
Area
Whole counties

County Palo Alto County, IA

The radar

The Des Moines radar (KDMX), 169 km from the middle of the area, began a volume at 13:22 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
Aug 24, 8:20 AM CDTThunderstorm Wind 52Graettinger, IA
Aug 24, 8:20 AM CDTThunderstorm Wind 52Ayrshire, IA

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 watch it was issued in

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

IssuedProductOfficeLasted
Aug 24, 7:45 AM CDTSevere Thunderstorm WatchSPC5 hr

The nearest sounding before it

Minneapolis, MN (KMPX), launched 12:00Z, 1.3 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, Minneapolis, MN at 12:00Z on 1998-08-24Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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, Minneapolis, MN at 12:00Z on 1998-08-24The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 9 square meters per square second.1939587897117Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1711 m above ground
0-6 km bulk shear
48 kt
0-1 km storm-relative helicity
9 m²/s²
0-3 km storm-relative helicity
108 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.

382 
WFUS1 KDSM 241321 RRA
TORDSM
IAC147-241355-

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE DES MOINES IA
820 AM CDT MON AUG 24 1998

THE NATIONAL WEATHER SERVICE IN DES MOINES HAS ISSUED A

* TORNADO WARNING FOR...
  PALO ALTO COUNTY IN NORTHWESTERN IOWA

* UNTIL 855 AM CDT

* AT 819 AM CDT... DOPPLER RADAR INDICATED A DEVELOPING TORNADO 21
  MILES EAST SOUTHEAST OF SPENCER OR 3 MILES SOUTHWEST OF EMMETSBURG
  MOVING EAST AT 45 MPH.

* THIS TORNADO CAN BE EXPECTED NEAR...
   EMMETSBURG         BY 827 AM CDT
   CYLINDER           BY 832 AM CDT
   RODMAN             BY 833 AM CDT

ABANDON MOBILE HOMES GO IN A NEARBY STURDY BUILDING. AS A LAST
RESORT LIE FLAT IN A DITCH AND COVER YOUR HEAD.

JOHNSON/SEARCY

What forecasters said that day

The local office's own words before this tornado 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, Aug 24, 6:00 AM CDT, 2 hours 20 minutes before
IAZ004>007-015>017-023>028-033>039-044>050-057>062-070>075-081>086-
092>097-250202-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
600 AM CDT MON AUG 24 1998

HAZARD--SCATTERED THUNDERSTORMS...SOME SEVERE WITH WIND GUSTS TO 80
MPH...ISOLATED TORNADOES...AND SOME HAIL.

AREA OF CONCERN AND TIMING DETAILS--HIGHEST THREAT AREA WILL BE
ALONG AND NORTH OF A POCAHONTAS TO HAMPTON TO TOLEDO/TAMA LINE FROM
100 PM TO 600 PM. SLIGHTLY LESS OF A THREAT SOUTH OF THAT LINE AND
NORTH OF A LINE FROM AUDUBON TO DES MOINES TO MONTEZUMA FROM 300 TO
800 PM.

METEOROLOGICAL COMMENTS--A NEARLY STATIONARY FRONT EXTENDING FROM A
LOW PRESSURE CENTER IN NORTH-CENTRAL NEBRASKA INTO CENTRAL IOWA WILL
MOVE BACK TO THE NORTH TODAY AS A WARM FRONT.  BY LATE THIS
AFTERNOON...THIS FRONT WILL EXTEND FROM NORTHEAST NEBRASKA THROUGH
NORTHERN IOWA.  MEANWHILE A STRONG UPPER LEVEL DISTURBANCE IN THE
NORTHERN PLAINS WILL MOVE SOUTHEAST INTO SOUTHEAST SOUTH DAKOTA AND
FROM THERE ALONG THE MINNESOTA/IOWA BORDER LATE THIS AFTERNOON INTO
THE EVENING HOURS.  THE WIND THROUGHOUT THE DEPTH OF THE ATMOSPHERE
WILL EXHIBIT A LARGE AMOUNT OF VEERING OR TURNING TODAY AND COULD
CAUSE STORMS TO ROTATE...ESPECIALLY ALONG AND NORTH OF THE WARM FRONT
IN NORTHERN IOWA.  IN THOSE LOCATIONS...SOME TORNADIC SUPERCELLS
WILL BE POSSIBLE. FARTHER SOUTH...IN CENTRAL IOWA...THE LOWEST LEVELS
OF THE ATMOSPHERE WILL NOT BE QUITE AS CONDICIVE TO THE TURNING
MOTION...SO THE TORNADIC POTENTIAL IS NOT NEAR AS GREAT. HOWEVER...
ONCE THE THUNDERSTORMS DEVELOP IN FAR NORTHWEST IOWA OR SOUTHEAST
SOUTH DAKOTA...THEY WILL STILL MOVE SOUTHEAST TOWARD THE OUTLOOK AREA
AND COULD MAKE THE TRANSITION INTO BOW ECHOS...WHICH WOULD BE CAPABLE
OF PRODUCING VERY STRONG WINDS DUE TO THEIR MOVEMENT TO THE SOUTHEAST
AT GREATER THAN 40 MPH. FINALLY...WITH WARM TEMPERATURES IN THE
ATMOSPHERE...LARGE HAIL IS ONLY A SECONDARY THREAT TODAY AND THIS
EVENING.  SINCE THE UPPER LEVEL SYSTEM IS MOVING QUICKLY...AND WINDS
AT MID-LEVELS WILL BE FAIRLY FAST...THE STORM POTENTIAL WILL DECREASE
RAPIDLY AFTER 800 OR 900 PM.

AN INITIAL AREA OF SHOWERS AND THUNDERSTORMS OVER NORTHEAST NEBRASKA
SHOULD DISSIPATE OVER WESTERN IOWA THIS MORNING AND ARE NOT EXPECTED
TO BECOME SEVERE.

PRECAUTIONS--SPOTTER ACTIVATION IS NOT ANTICIPATED THIS MORNING...
BUT WILL LIKELY BE NEEDED OVER THE NORTHERN TWO-THIRDS OF THE
STATE THIS AFTERNOON AND EVENING. FOR THE LATEST UPDATES ON THIS
DEVELOPING WEATHER SITUATION...STAY TUNED TO YOUR NOAA WEATHER
RADIO...OR YOUR FAVORITE TELEVISION OR CABLE AFFILIATES FOR UPDATED
CENTRAL IOWA THUNDERSTORM OUTLOOKS...FORECASTS AND WATCHES LATER
TODAY.

SEARCY
Special weather statement, Aug 24, 6:00 AM CDT, 2 hours 20 minutes before
IAZ004>007-015>017-023>028-033>039-044>050-057>062-070>075-081>086-
092>097-250202-

CENTRAL IOWA THUNDERSTORM OUTLOOK...CORRECTED MND HEADER TYPE...
NATIONAL WEATHER SERVICE DES MOINES IA
600 AM CDT MON AUG 24 1998

HAZARD--SCATTERED THUNDERSTORMS...SOME SEVERE WITH WIND GUSTS TO 80
MPH...ISOLATED TORNADOES...AND SOME HAIL.

AREA OF CONCERN AND TIMING DETAILS--HIGHEST THREAT AREA WILL BE
ALONG AND NORTH OF A POCAHONTAS TO HAMPTON TO TOLEDO/TAMA LINE FROM
100 PM TO 600 PM. SLIGHTLY LESS OF A THREAT SOUTH OF THAT LINE AND
NORTH OF A LINE FROM AUDUBON TO DES MOINES TO MONTEZUMA FROM 300 TO
800 PM.

METEOROLOGICAL COMMENTS--A NEARLY STATIONARY FRONT EXTENDING FROM A
LOW PRESSURE CENTER IN NORTH-CENTRAL NEBRASKA INTO CENTRAL IOWA WILL
MOVE BACK TO THE NORTH TODAY AS A WARM FRONT.  BY LATE THIS
AFTERNOON...THIS FRONT WILL EXTEND FROM NORTHEAST NEBRASKA THROUGH
NORTHERN IOWA.  MEANWHILE A STRONG UPPER LEVEL DISTURBANCE IN THE
NORTHERN PLAINS WILL MOVE SOUTHEAST INTO SOUTHEAST SOUTH DAKOTA AND
FROM THERE ALONG THE MINNESOTA/IOWA BORDER LATE THIS AFTERNOON INTO
THE EVENING HOURS.  THE WIND THROUGHOUT THE DEPTH OF THE ATMOSPHERE
WILL EXHIBIT A LARGE AMOUNT OF VEERING OR TURNING TODAY AND COULD
CAUSE STORMS TO ROTATE...ESPECIALLY ALONG AND NORTH OF THE WARM FRONT
IN NORTHERN IOWA.  IN THOSE LOCATIONS...SOME TORNADIC SUPERCELLS
WILL BE POSSIBLE. FARTHER SOUTH...IN CENTRAL IOWA...THE LOWEST LEVELS
OF THE ATMOSPHERE WILL NOT BE QUITE AS CONDICIVE TO THE TURNING
MOTION...SO THE TORNADIC POTENTIAL IS NOT NEAR AS GREAT. HOWEVER...
ONCE THE THUNDERSTORMS DEVELOP IN FAR NORTHWEST IOWA OR SOUTHEAST
SOUTH DAKOTA...THEY WILL STILL MOVE SOUTHEAST TOWARD THE OUTLOOK AREA
AND COULD MAKE THE TRANSITION INTO BOW ECHOS...WHICH WOULD BE CAPABLE
OF PRODUCING VERY STRONG WINDS DUE TO THEIR MOVEMENT TO THE SOUTHEAST
AT GREATER THAN 40 MPH. FINALLY...WITH WARM TEMPERATURES IN THE
ATMOSPHERE...LARGE HAIL IS ONLY A SECONDARY THREAT TODAY AND THIS
EVENING.  SINCE THE UPPER LEVEL SYSTEM IS MOVING QUICKLY...AND WINDS
AT MID-LEVELS WILL BE FAIRLY FAST...THE STORM POTENTIAL WILL DECREASE
RAPIDLY AFTER 800 OR 900 PM.

AN INITIAL AREA OF SHOWERS AND THUNDERSTORMS OVER NORTHEAST NEBRASKA
SHOULD DISSIPATE OVER WESTERN IOWA THIS MORNING AND ARE NOT EXPECTED
TO BECOME SEVERE.

PRECAUTIONS--SPOTTER ACTIVATION IS NOT ANTICIPATED THIS MORNING...
BUT WILL LIKELY BE NEEDED OVER THE NORTHERN TWO-THIRDS OF THE
STATE THIS AFTERNOON AND EVENING. FOR THE LATEST UPDATES ON THIS
DEVELOPING WEATHER SITUATION...STAY TUNED TO YOUR NOAA WEATHER
RADIO...OR YOUR FAVORITE TELEVISION OR CABLE AFFILIATES FOR UPDATED
CENTRAL IOWA THUNDERSTORM OUTLOOKS...FORECASTS AND WATCHES LATER
TODAY.

SEARCY
Special weather statement, Aug 24, 6:00 AM CDT, 2 hours 20 minutes before
IAZ004>007-015>017-023>028-033>039-044>050-057>062-070>075-081>086-
092>097-250202-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
600 AM CDT MON AUG 24 1998

HAZARD--SCATTERED THUNDERSTORMS...SOME SEVERE WITH WIND GUSTS TO 80
MPH...ISOLATED TORNADOES...AND SOME HAIL.

AREA OF CONCERN AND TIMING DETAILS--HIGHEST THREAT AREA WILL BE
ALONG AND NORTH OF A POCAHONTAS TO HAMPTON TO TOLEDO/TAMA LINE FROM
100 PM TO 600 PM. SLIGHTLY LESS OF A THREAT SOUTH OF THAT LINE AND
NORTH OF A LINE FROM AUDUBON TO DES MOINES TO MONTEZUMA FROM 300 TO
800 PM.

METEOROLOGICAL COMMENTS--A NEARLY STATIONARY FRONT EXTENDING FROM A
LOW PRESSURE CENTER IN NORTH-CENTRAL NEBRASKA INTO CENTRAL IOWA WILL
MOVE BACK TO THE NORTH TODAY AS A WARM FRONT.  BY LATE THIS
AFTERNOON...THIS FRONT WILL EXTEND FROM NORTHEAST NEBRASKA THROUGH
NORTHERN IOWA.  MEANWHILE A STRONG UPPER LEVEL DISTURBANCE IN THE
NORTHERN PLAINS WILL MOVE SOUTHEAST INTO SOUTHEAST SOUTH DAKOTA AND
FROM THERE ALONG THE MINNESOTA/IOWA BORDER LATE THIS AFTERNOON INTO
THE EVENING HOURS.  THE WIND THROUGHOUT THE DEPTH OF THE ATMOSPHERE
WILL EXHIBIT A LARGE AMOUNT OF VEERING OR TURNING TODAY AND COULD
CAUSE STORMS TO ROTATE...ESPECIALLY ALONG AND NORTH OF THE WARM FRONT
IN NORTHERN IOWA.  IN THOSE LOCATIONS...SOME TORNADIC SUPERCELLS
WILL BE POSSIBLE. FARTHER SOUTH...IN CENTRAL IOWA...THE LOWEST LEVELS
OF THE ATMOSPHERE WILL NOT BE QUITE AS CONDICIVE TO THE TURNING
MOTION...SO THE TORNADIC POTENTIAL IS NOT NEAR AS GREAT. HOWEVER...
ONCE THE THUNDERSTORMS DEVELOP IN FAR NORTHWEST IOWA OR SOUTHEAST
SOUTH DAKOTA...THEY WILL STILL MOVE SOUTHEAST TOWARD THE OUTLOOK AREA
AND COULD MAKE THE TRANSITION INTO BOW ECHOS...WHICH WOULD BE CAPABLE
OF PRODUCING VERY STRONG WINDS DUE TO THEIR MOVEMENT TO THE SOUTHEAST
AT GREATER THAN 40 MPH. FINALLY...WITH WARM TEMPERATURES IN THE
ATMOSPHERE...LARGE HAIL IS ONLY A SECONDARY THREAT TODAY AND THIS
EVENING.  SINCE THE UPPER LEVEL SYSTEM IS MOVING QUICKLY...AND WINDS
AT MID-LEVELS WILL BE FAIRLY FAST...THE STORM POTENTIAL WILL DECREASE
RAPIDLY AFTER 800 OR 900 PM.

AN INITIAL AREA OF SHOWERS AND THUNDERSTORMS OVER NORTHEAST NEBRASKA
SHOULD DISSIPATE OVER WESTERN IOWA THIS MORNING AND ARE NOT EXPECTED
TO BECOME SEVERE.

PRECAUTIONS--SPOTTER ACTIVATION IS NOT ANTICIPATED THIS MORNING...
BUT WILL LIKELY BE NEEDED OVER THE NORTHERN TWO-THIRDS OF THE
STATE THIS AFTERNOON AND EVENING. FOR THE LATEST UPDATES ON THIS
DEVELOPING WEATHER SITUATION...STAY TUNED TO YOUR NOAA WEATHER
RADIO...OR YOUR FAVORITE TELEVISION OR CABLE AFFILIATES FOR UPDATED
CENTRAL IOWA THUNDERSTORM OUTLOOKS...FORECASTS AND WATCHES LATER
TODAY.

SEARCY
Special weather statement, Aug 24, 6:00 AM CDT, 2 hours 20 minutes before
IAZ004>007-015>017-023>028-033>039-044>050-057>062-070>075-081>086-
092>097-250202-

CENTRAL IOWA THUNDERSTORM OUTLOOK...CORRECTED MND HEADER TYPE...
NATIONAL WEATHER SERVICE DES MOINES IA
600 AM CDT MON AUG 24 1998

HAZARD--SCATTERED THUNDERSTORMS...SOME SEVERE WITH WIND GUSTS TO 80
MPH...ISOLATED TORNADOES...AND SOME HAIL.

AREA OF CONCERN AND TIMING DETAILS--HIGHEST THREAT AREA WILL BE
ALONG AND NORTH OF A POCAHONTAS TO HAMPTON TO TOLEDO/TAMA LINE FROM
100 PM TO 600 PM. SLIGHTLY LESS OF A THREAT SOUTH OF THAT LINE AND
NORTH OF A LINE FROM AUDUBON TO DES MOINES TO MONTEZUMA FROM 300 TO
800 PM.

METEOROLOGICAL COMMENTS--A NEARLY STATIONARY FRONT EXTENDING FROM A
LOW PRESSURE CENTER IN NORTH-CENTRAL NEBRASKA INTO CENTRAL IOWA WILL
MOVE BACK TO THE NORTH TODAY AS A WARM FRONT.  BY LATE THIS
AFTERNOON...THIS FRONT WILL EXTEND FROM NORTHEAST NEBRASKA THROUGH
NORTHERN IOWA.  MEANWHILE A STRONG UPPER LEVEL DISTURBANCE IN THE
NORTHERN PLAINS WILL MOVE SOUTHEAST INTO SOUTHEAST SOUTH DAKOTA AND
FROM THERE ALONG THE MINNESOTA/IOWA BORDER LATE THIS AFTERNOON INTO
THE EVENING HOURS.  THE WIND THROUGHOUT THE DEPTH OF THE ATMOSPHERE
WILL EXHIBIT A LARGE AMOUNT OF VEERING OR TURNING TODAY AND COULD
CAUSE STORMS TO ROTATE...ESPECIALLY ALONG AND NORTH OF THE WARM FRONT
IN NORTHERN IOWA.  IN THOSE LOCATIONS...SOME TORNADIC SUPERCELLS
WILL BE POSSIBLE. FARTHER SOUTH...IN CENTRAL IOWA...THE LOWEST LEVELS
OF THE ATMOSPHERE WILL NOT BE QUITE AS CONDICIVE TO THE TURNING
MOTION...SO THE TORNADIC POTENTIAL IS NOT NEAR AS GREAT. HOWEVER...
ONCE THE THUNDERSTORMS DEVELOP IN FAR NORTHWEST IOWA OR SOUTHEAST
SOUTH DAKOTA...THEY WILL STILL MOVE SOUTHEAST TOWARD THE OUTLOOK AREA
AND COULD MAKE THE TRANSITION INTO BOW ECHOS...WHICH WOULD BE CAPABLE
OF PRODUCING VERY STRONG WINDS DUE TO THEIR MOVEMENT TO THE SOUTHEAST
AT GREATER THAN 40 MPH. FINALLY...WITH WARM TEMPERATURES IN THE
ATMOSPHERE...LARGE HAIL IS ONLY A SECONDARY THREAT TODAY AND THIS
EVENING.  SINCE THE UPPER LEVEL SYSTEM IS MOVING QUICKLY...AND WINDS
AT MID-LEVELS WILL BE FAIRLY FAST...THE STORM POTENTIAL WILL DECREASE
RAPIDLY AFTER 800 OR 900 PM.

AN INITIAL AREA OF SHOWERS AND THUNDERSTORMS OVER NORTHEAST NEBRASKA
SHOULD DISSIPATE OVER WESTERN IOWA THIS MORNING AND ARE NOT EXPECTED
TO BECOME SEVERE.

PRECAUTIONS--SPOTTER ACTIVATION IS NOT ANTICIPATED THIS MORNING...
BUT WILL LIKELY BE NEEDED OVER THE NORTHERN TWO-THIRDS OF THE
STATE THIS AFTERNOON AND EVENING. FOR THE LATEST UPDATES ON THIS
DEVELOPING WEATHER SITUATION...STAY TUNED TO YOUR NOAA WEATHER
RADIO...OR YOUR FAVORITE TELEVISION OR CABLE AFFILIATES FOR UPDATED
CENTRAL IOWA THUNDERSTORM OUTLOOKS...FORECASTS AND WATCHES LATER
TODAY.

SEARCY
Special weather statement, Aug 24, 7:29 AM CDT, 51 minutes before
IAZ004>007-015>017-023>028-033>039-044>050-057>062-070>075-081>086-
092>097-250202-

CENTRAL IOWA THUNDERSTORM OUTLOOK...UPDATED...
NATIONAL WEATHER SERVICE DES MOINES IA
729 AM CDT MON AUG 24 1998

HAZARD--SCATTERED THUNDERSTORMS...SOME SEVERE WITH WIND GUSTS TO 80
MPH...ISOLATED TORNADOES...AND SOME HAIL.

AREA OF CONCERN AND TIMING DETAILS--HIGHEST THREAT AREA WILL BE
ALONG AND NORTH OF A POCAHONTAS TO HAMPTON TO TOLEDO/TAMA LINE THIS
MORNING...AND THEN AGAIN THIS AFTERNOON. SLIGHTLY LESS OF A THREAT
SOUTH OF THAT LINE AND NORTH OF A LINE FROM AUDUBON TO DES MOINES TO
MONTEZUMA THIS MORNING AND AGAIN FROM 200 TO 800 PM.

METEOROLOGICAL COMMENTS--THUNDERSTORMS OVER SOUTHEAST SOUTH DAKOTA
CONTINUE TO STRENGTHEN AS THEY MOVE TOWARD NORTHWEST IOWA FROM
SOUTHEAST SOUTH DAKOTA.  THEIR SOUTHEASTWARD MOVEMENT CONTINUES TO
TAKE THEM INTO DEEPER MOISTURE...OVER NORTHERN IOWA.  SOME OF THESE
STORMS COULD BE SEVERE OVER PARTS OF NORTHERN IOWA THIS MORNING.
DAMAGING WINDS AND HAIL WOULD BE THE MAIN THREAT.  THEN...A NEARLY
STATIONARY FRONT EXTENDING FROM A LOW PRESSURE CENTER IN
NORTH-CENTRAL NEBRASKA INTO CENTRAL IOWA WILL MOVE BACK TO THE NORTH
TODAY AS A WARM FRONT.  BY LATE THIS AFTERNOON...THIS FRONT WILL
EXTEND FROM NORTHEAST NEBRASKA THROUGH NORTHERN IOWA.  MEANWHILE A
STRONG UPPER LEVEL DISTURBANCE IN THE NORTHERN PLAINS WILL MOVE
SOUTHEAST INTO SOUTHEAST SOUTH DAKOTA AND FROM THERE ALONG THE
MINNESOTA/IOWA BORDER LATE THIS AFTERNOON INTO THE EVENING HOURS.
THE WIND THROUGHOUT THE DEPTH OF THE ATMOSPHERE WILL EXHIBIT A LARGE
AMOUNT OF VEERING OR TURNING TODAY AND COULD CAUSE STORMS TO
ROTATE...ESPECIALLY ALONG AND NORTH OF THE WARM FRONT IN NORTHERN
IOWA.  IN THOSE LOCATIONS...SOME TORNADIC SUPERCELLS WILL BE
POSSIBLE. FARTHER SOUTH...IN CENTRAL IOWA...THE LOWEST LEVELS
OF THE ATMOSPHERE WILL NOT BE QUITE AS CONDUCIVE TO THE TURNING
MOTION...SO THE TORNADIC POTENTIAL IS NOT NEAR AS GREAT. HOWEVER...
ONCE THE THUNDERSTORMS DEVELOP IN FAR NORTHWEST IOWA OR SOUTHEAST
SOUTH DAKOTA...THEY WILL STILL MOVE SOUTHEAST TOWARD THE OUTLOOK AREA
AND COULD MAKE THE TRANSITION INTO BOW ECHOS...WHICH WOULD BE CAPABLE
OF PRODUCING VERY STRONG WINDS DUE TO THEIR MOVEMENT TO THE SOUTHEAST
AT GREATER THAN 40 MPH. FINALLY...WITH WARM TEMPERATURES IN THE
ATMOSPHERE...LARGE HAIL IS ONLY A SECONDARY THREAT TODAY AND THIS
EVENING.  SINCE THE UPPER LEVEL SYSTEM IS MOVING QUICKLY...AND WINDS
AT MID-LEVELS WILL BE FAIRLY FAST...THE STORM POTENTIAL WILL DECREASE
RAPIDLY AFTER 800 OR 900 PM.

PRECAUTIONS--SPOTTER ACTIVATION MAY BE REQUIRED THROUGHOUT THE
DAY...ESPECIALLY OVER NORTHERN AND CENTRAL IOWA. FOR THE LATEST
UPDATES ON THIS DEVELOPING WEATHER SITUATI6ON...STAY TUNED TO YOUR
NOAA WEATHER RADIO...OR YOUR FAVORITE TELEVISION OR CABLE AFFILIATES
FOR UPDATED CENTRAL IOWA THUNDERSTORM OUTLOOKS...FORECASTS AND
WATCHES LATER TODAY.

SEARCY

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 24, 8:07 AM CDTSevere Thunderstorm WarningDMXEmmet, Palo Alto48 min
Aug 24, 8:34 AM CDTSevere Thunderstorm WarningDMXWright36 min
Aug 24, 8:36 AM CDTSevere Thunderstorm WarningDMXKossuth49 min
Aug 24, 8:56 AM CDTSevere Thunderstorm WarningDMXFranklin49 min
Aug 24, 9:02 AM CDTSevere Thunderstorm WarningDMXHumboldt33 min
Aug 24, 9:20 AM CDTSevere Thunderstorm WarningDMXWright35 min
Aug 24, 9:27 AM CDTSevere Thunderstorm WarningDMXButler33 min
Aug 24, 9:37 AM CDTSevere Thunderstorm WarningDMXGrundy33 min
Aug 24, 9:54 AM CDTSevere Thunderstorm WarningDMXBlack Hawk36 min
Aug 24, 10:24 AM CDTTornado WarningDMXBlack Hawk31 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.