Alert archive / Iowa / Severe Thunderstorm Warnings in 1998

Severe Thunderstorm Warning 159, NWS Des Moines, IA

June 11, 1998Jasper County, Iowa

NWS Des Moines, IA issued this severe thunderstorm warning at Jun 11, 1998, 1:43 PM CDT for Jasper County, Iowa. It was in force for 17 min. 3 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
Jun 11, 1998, 1:43 PM CDT (18:43 UTC)
Expired
Jun 11, 1998, 2:00 PM CDT
In force
17 min
Issued by
NWS Des Moines, IA
Area
Whole counties

County Jasper County, IA

What was reported inside it

TimeReportWhereRemark
Jun 11, 1:45 PM CDTThunderstorm Wind 52Colfax, IA
Jun 11, 1:50 PM CDTThunderstorm Wind 50Baxter, IA
Jun 11, 2:00 PM CDTThunderstorm Wind 56Newburg, 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 nearest sounding before it

Davenport, (KDVN), launched 12:00Z, 6.7 hours before the alert went out and 212 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 12:00Z on 1998-06-11Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 475 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 12:00Z on 1998-06-11The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 163 square meters per square second.1939587897Sfc1 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
475 J/kg
Mixed-layer CIN
-50 J/kg
Mixed-layer LCL
569 m above ground
0-6 km bulk shear
52 kt
0-1 km storm-relative helicity
163 m²/s²
0-3 km storm-relative helicity
207 m²/s²
Significant tornado parameter
0.6
Supercell composite
4.6

Open this sounding in Storm Lab

The text

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

514 
WUUS1 KDSM 111844 RRA
SVRDSM
IAC099-111900-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE DES MOINES IA
143 PM CDT THU JUN 11 1998

THE NATIONAL WEATHER SERVICE IN DES MOINES HAS ISSUED A

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

* UNTIL 200 PM CDT

* AT 140 PM CDT... STORM SPOTTERS REPORTED A LINE OF SEVERE
  THUNDERSTORMS JUST WEST OF NEWTON OR 25 MILES EAST OF DES
  MOINES MOVING EAST NORTHEAST AT 45 MPH.

* THIS SEVERE THUNDERSTORM CAN BE EXPECTED NEAR...
   NEWTON                         NOW
   ROCK CREEK STATE PARK          153 PM CDT.

DAMAGING WINDS AND HEAVY RAIN ARE LIKELY. GO INSIDE A STURDY
BUILDING AND STAY AWAY FROM WINDOWS WINDOWS WERE BLOWN OUT OF HOMES
JUST WEST OF COLFAX AT 135 PM

PYTLAK

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, Jun 11, 11:08 AM CDT, 2 hours 35 minutes before
IAZ004>007-015>017-023>028-033>039-044>050-057>062-070>075-081>086-
092>097-120000-

CENTRAL IOWA THUNDERSTORM OUTLOOK
NATIONAL WEATHER SERVICE DES MOINES IA
1108 AM CDT THU JUN 11 1998

HAZARD--WIDESPREAD THUNDERSTORMS PRODUCING 1 TO 2 INCHES OF RAIN AND
ISOLATED AMOUNTS UP TO 3 INCHES. ISOLATED SEVERE THUNDERSTORMS WITH
WIND GUSTS TO 65 MPH ARE ALSO POSSIBLE.

AREA OF CONCERN--THE HEAVY RAIN THREAT EXISTS OVER ALL OF CENTRAL
IOWA...WITH THE HEAVIEST WIDESPREAD RAIN EXPECTED NORTHWEST OF A
CRESTON-DES MOINES-WATERLOO LINE. SOUTHEAST OF THIS LINE IS WHERE
THE RISK OF ISOLATED SEVERE WEATHER EXISTS.

TIMING DETAILS--THE HEAVY RAIN THREAT WILL CONTINUE THROUGH AROUND
800 PM. THE SEVERE WEATHER THREAT EXISTS IN SOUTH CENTRAL AND
SOUTHEAST IOWA BETWEEN 400 AND 800 PM.

METEOROLOGICAL COMMENTS--A POTENT UPPER LEVEL DISTURBANCE OVER
EASTERN NEBRASKA IS DRAGGING A WARM FRONT INTO SOUTHEAST IOWA.
WIDESPREAD HEAVY RAIN AND THUNDERSTORMS HAVE BROKEN OUT ALONG AND
NORTH OF THE WARM FRONT WITH A FEW SPOTS REPORTING SMALL STREAM AND
URBAN FLOODING EARLIER THIS MORNING. INDIVIDUAL STORM MOTION IS
AT OVER 40 MPH AND SINCE THE SOAKING RAIN IS FALLING OVER A PROLONGED
PERIOD...THE FLASH FLOOD THREAT DOES NOT APPEAR TO BE AS HIGH AS
WIDESPREAD SMALL STREAM AND URBAN FLOODING.

LATER TODAY...A DRY SLOT RACING NORTHEAST ACROSS KANSAS IS EXPECTED
TO ENTER THE SOUTHEAST HALF OF THE STATE DURING THE LATE AFTERNOON
HOURS. IF THIS CAUSES SKIES TO CLEAR FOR EVEN AN HOUR OR TWO THE
ATMOSPHERE WILL RAPIDLY DESTABILIZE AND CAUSE MORE THUNDERSTORMS TO
DEVELOP ALONG A COLD FRONT WHICH WILL MOVE ACROSS SOUTHERN IOWA EARLY
THIS EVENING. SOUTHWEST WINDS ALOFT IN THE 50 TO 70 MPH RANGE WOULD
THEN CAUSE ANY STORMS THAT DEVELOP TO PRODUCE STRAIGHT LINE WINDS AND
POSSIBLY SOME HAIL.

PRECAUTIONS--THE RISK OF SEVERE WEATHER IS MINIMAL AS LONG AS SKIES
REMAIN CLOUDY. IF ANY SUN BREAKS OUT IN SOUTH CENTRAL AND
SOUTHEAST IOWA...EMERGENCY MANAG"ERS SHOULD PREPARE FOR SPOTTER
ACTIVATION. SHERIFFS DEPARTMENTS AND STORM SPOTTERS SHOULD REPORT
ANY HIGH WATER THEY OBSERVE.

PYTLAK
Special weather statement, Jun 11, 11:08 AM CDT, 2 hours 35 minutes before
IAZ004>007-015>017-023>028-033>039-044>050-057>062-070>075-081>086-
092>097-120000-

CENTRAL IOWA THUNDERSTORM OUTLOOK
NATIONAL WEATHER SERVICE DES MOINES IA
1108 AM CDT THU JUN 11 1998

HAZARD--WIDESPREAD THUNDERSTORMS PRODUCING 1 TO 2 INCHES OF RAIN AND
ISOLATED AMOUNTS UP TO 3 INCHES. ISOLATED SEVERE THUNDERSTORMS WITH
WIND GUSTS TO 65 MPH ARE ALSO POSSIBLE.

AREA OF CONCERN--THE HEAVY RAIN THREAT EXISTS OVER ALL OF CENTRAL
IOWA...WITH THE HEAVIEST WIDESPREAD RAIN EXPECTED NORTHWEST OF A
CRESTON-DES MOINES-WATERLOO LINE. SOUTHEAST OF THIS LINE IS WHERE
THE RISK OF ISOLATED SEVERE WEATHER EXISTS.

TIMING DETAILS--THE HEAVY RAIN THREAT WILL CONTINUE THROUGH AROUND
800 PM. THE SEVERE WEATHER THREAT EXISTS IN SOUTH CENTRAL AND
SOUTHEAST IOWA BETWEEN 400 AND 800 PM.

METEOROLOGICAL COMMENTS--A POTENT UPPER LEVEL DISTURBANCE OVER
EASTERN NEBRASKA IS DRAGGING A WARM FRONT INTO SOUTHEAST IOWA.
WIDESPREAD HEAVY RAIN AND THUNDERSTORMS HAVE BROKEN OUT ALONG AND
NORTH OF THE WARM FRONT WITH A FEW SPOTS REPORTING SMALL STREAM AND
URBAN FLOODING EARLIER THIS MORNING. INDIVIDUAL STORM MOTION IS
AT OVER 40 MPH AND SINCE THE SOAKING RAIN IS FALLING OVER A PROLONGED
PERIOD...THE FLASH FLOOD THREAT DOES NOT APPEAR TO BE AS HIGH AS
WIDESPREAD SMALL STREAM AND URBAN FLOODING.

LATER TODAY...A DRY SLOT RACING NORTHEAST ACROSS KANSAS IS EXPECTED
TO ENTER THE SOUTHEAST HALF OF THE STATE DURING THE LATE AFTERNOON
HOURS. IF THIS CAUSES SKIES TO CLEAR FOR EVEN AN HOUR OR TWO THE
ATMOSPHERE WILL RAPIDLY DESTABILIZE AND CAUSE MORE THUNDERSTORMS TO
DEVELOP ALONG A COLD FRONT WHICH WILL MOVE ACROSS SOUTHERN IOWA EARLY
THIS EVENING. SOUTHWEST WINDS ALOFT IN THE 50 TO 70 MPH RANGE WOULD
THEN CAUSE ANY STORMS THAT DEVELOP TO PRODUCE STRAIGHT LINE WINDS AND
POSSIBLY SOME HAIL.

PRECAUTIONS--THE RISK OF SEVERE WEATHER IS MINIMAL AS LONG AS SKIES
REMAIN CLOUDY. IF ANY SUN BREAKS OUT IN SOUTH CENTRAL AND
SOUTHEAST IOWA...EMERGENCY MANAG"ERS SHOULD PREPARE FOR SPOTTER
ACTIVATION. SHERIFFS DEPARTMENTS AND STORM SPOTTERS SHOULD REPORT
ANY HIGH WATER THEY OBSERVE.

PYTLAK
Special weather statement, Jun 11, 1:28 PM CDT, 15 minutes before
IAZ004>007-015>017-023>028-033>039-044>050-057>062-070>075-081>086-
092>097-120100-

CENTRAL IOWA THUNDERSTORM OUTLOOK
NATIONAL WEATHER SERVICE DES MOINES IA
128 PM CDT THU JUN 11 1998

HAZARD--SCATTERED THUNDERSTORMS PRODUCING 1 TO 2 INCHES OF RAIN.

AREA OF CONCERN--ALL OF CENTRAL IOWA...BUT THE THREAT WILL DECREASE
AS THE AFTERNOON AND EVENING WEARS ON.

TIMING DETAILS--THROUGH 400 PM...AND AGAIN FROM 700 PM UNTIL 1100 PM.

METEOROLOGICAL COMMENTS--THE STORM SYSTEM WHICH PRODUCED HEAVY RAIN
OVER MUCH OF THE STATE TODAY HAS ACCELERATED RAPIDLY SINCE LATE
MORNING INTO CENTRAL IOWA. ISOLATED STRONG THUNDERSTORMS HAVE
DEVELOPED OVER CENTRAL IOWA AND HAVE BEEN PRODUCING UP TO 2 INCHES
OF RAIN IN AN HOUR...BUT THEY WERE MOVING NORTHEAST AT 50 MPH AND
THE SUN WAS BREAKING OUT OVER MUCH OF WESTERN IOWA. WINDS HAVE
SHIFTED TO THE WEST AND NORTHWEST BEHIND THIS LOW...GREATLY
REDUCING CONVERGENCE AND THE THREAT OF REDEVELOPMENT LATER THIS
AFTERNOON. THERE IS ANOTHER COLD FRONT DROPPING SOUTHEAST OUT OF
SOUTH DAKOTA AND IT IS EXPECTED TO MOVE INTO THE STATE EARLY THIS
EVENING. IT MAY BE ENOUGH TO CAUSE SOME CONVERGENCE AND REFIRE
THUNDERSTORMS...BUT WITH THE LOSS OF DAYTIME HEATING AND
MOISTURE...THERE IS A GOOD CHANCE THEY WILL REMAIN BELOW SEVERE
LEVELS.

PRECAUTIONS--MINOR SMALL STREAM AND STREET FLOODING IS POSSIBLE
AS THE FIRST LOW PULLS OUT OF THE AREA. ADDITIONAL REDEVELOPMENT IS
POSSIBLE LATER THIS EVENING AND WILL BE MONITORED FOR SIGNS OF
HEAVY RAIN OR SEVERE WEATHER. HOWEVER THE THREAT APPEARS TO BE
DIMINISHING.

PYTLAK
Special weather statement, Jun 11, 1:28 PM CDT, 15 minutes before
IAZ004>007-015>017-023>028-033>039-044>050-057>062-070>075-081>086-
092>097-120100-

CENTRAL IOWA THUNDERSTORM OUTLOOK
NATIONAL WEATHER SERVICE DES MOINES IA
128 PM CDT THU JUN 11 1998

HAZARD--SCATTERED THUNDERSTORMS PRODUCING 1 TO 2 INCHES OF RAIN.

AREA OF CONCERN--ALL OF CENTRAL IOWA...BUT THE THREAT WILL DECREASE
AS THE AFTERNOON AND EVENING WEARS ON.

TIMING DETAILS--THROUGH 400 PM...AND AGAIN FROM 700 PM UNTIL 1100 PM.

METEOROLOGICAL COMMENTS--THE STORM SYSTEM WHICH PRODUCED HEAVY RAIN
OVER MUCH OF THE STATE TODAY HAS ACCELERATED RAPIDLY SINCE LATE
MORNING INTO CENTRAL IOWA. ISOLATED STRONG THUNDERSTORMS HAVE
DEVELOPED OVER CENTRAL IOWA AND HAVE BEEN PRODUCING UP TO 2 INCHES
OF RAIN IN AN HOUR...BUT THEY WERE MOVING NORTHEAST AT 50 MPH AND
THE SUN WAS BREAKING OUT OVER MUCH OF WESTERN IOWA. WINDS HAVE
SHIFTED TO THE WEST AND NORTHWEST BEHIND THIS LOW...GREATLY
REDUCING CONVERGENCE AND THE THREAT OF REDEVELOPMENT LATER THIS
AFTERNOON. THERE IS ANOTHER COLD FRONT DROPPING SOUTHEAST OUT OF
SOUTH DAKOTA AND IT IS EXPECTED TO MOVE INTO THE STATE EARLY THIS
EVENING. IT MAY BE ENOUGH TO CAUSE SOME CONVERGENCE AND REFIRE
THUNDERSTORMS...BUT WITH THE LOSS OF DAYTIME HEATING AND
MOISTURE...THERE IS A GOOD CHANCE THEY WILL REMAIN BELOW SEVERE
LEVELS.

PRECAUTIONS--MINOR SMALL STREAM AND STREET FLOODING IS POSSIBLE
AS THE FIRST LOW PULLS OUT OF THE AREA. ADDITIONAL REDEVELOPMENT IS
POSSIBLE LATER THIS EVENING AND WILL BE MONITORED FOR SIGNS OF
HEAVY RAIN OR SEVERE WEATHER. HOWEVER THE THREAT APPEARS TO BE
DIMINISHING.

PYTLAK

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; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive.