Alert archive / Iowa / Severe Thunderstorm Warnings in 1998
Severe Thunderstorm Warning 174, NWS Des Moines, IA
NWS Des Moines, IA issued this severe thunderstorm warning at Jun 18, 1998, 10:54 AM CDT for Polk County, Iowa. It was in force for 31 min. 5 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 18, 1998, 10:54 AM CDT (15:54 UTC)
- Expired
- Jun 18, 1998, 11:25 AM CDT
- In force
- 31 min
- Issued by
- NWS Des Moines, IA
- Area
- Whole counties
County Polk County, IA
The radar
The Des Moines radar (KDMX), 13 km from the middle of the area, began a volume at 15:54 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
| Time | Report | Where | Remark |
|---|---|---|---|
| Jun 18, 11:02 AM CDT | Thunderstorm Wind 50 | Altoona, IA | |
| Jun 18, 11:13 AM CDT | Thunderstorm Wind 69 | Des Moines, IA | |
| Jun 18, 11:14 AM CDT | Thunderstorm Wind 56 | Des Moines, IA | |
| Jun 18, 11:20 AM CDT | Thunderstorm Wind 50 | Urbandale, IA | |
| Jun 18, 11:24 AM CDT | Thunderstorm Wind 50 | Altoona, 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
Omaha, NE (KOAX), launched 12:00Z, 3.9 hours before the alert went out and 236 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.
- Mixed-layer CAPE
- 245 J/kg
- Mixed-layer CIN
- -251 J/kg
- Mixed-layer LCL
- 1451 m above ground
- 0-6 km bulk shear
- 67 kt
- 0-1 km storm-relative helicity
- -105 m²/s²
- 0-3 km storm-relative helicity
- -51 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- -1.0
The text
As transmitted, in the capitals the NWS used until 2016.
139 WUUS1 KDSM 181554 RRA SVRDSM IAC153-181625- BULLETIN - IMMEDIATE BROADCAST REQUESTED SEVERE THUNDERSTORM WARNING NATIONAL WEATHER SERVICE DES MOINES IA 1054 AM CDT THU JUN 18 1998 THE NATIONAL WEATHER SERVICE IN DES MOINES HAS ISSUED A * SEVERE THUNDERSTORM WARNING FOR... POLK COUNTY IN CENTRAL IOWA * UNTIL 1125 AM CDT * AT 1052 AM CDT... DOPPLER RADAR INDICATED A SEVERE THUNDERSTORM IN THE VICINITY OF DES MOINES MOVING NORTH NORTHEAST AT 45 MPH. DES MOINES NOW JOHNSTON BY 1055 AM CDT SAYLORVILLE RESERVOIR BY 1055 AM CDT ANKENY BY 1058 AM CDT THIS IS A DANGEROUS STORM STAY INDOORS AWAY FROM WINDOWS. JJ/BS
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 18, 5:10 AM CDT, 5 hours 44 minutes before
IAZ004>007-015>017-023>028-033>039-044>050-057>062-070>075-081>086- 092>097-182100- CENTRAL IOWA THUNDERSTORM OUTLOOK NATIONAL WEATHER SERVICE DES MOINES IA 510 AM CDT THU JUN 18 1998 HAZARD--SCATTERED THUNDERSTORMS WITH HEAVY RAINFALL OF 2 TO 3 INCHES IN A FEW LOCATIONS...LARGE HAIL AND WIND GUSTS TO 60 MPH. TIMING AND AREA OF CONCERN--THIS MORNING ALONG AND EAST OF A LINE FROM FOREST CITY...TO WEBSTER CITY...TO DES MOINES...TO CRESTON. THIS AFTERNOON OVER ALL OF CENTRAL AND EASTERN IOWA. METEOROLOGICAL COMMENTS--EARLY THIS MORNING...A LINE OF STRONG THUNDERSTORMS EXTENDING FROM NORTH-CENTRAL IOWA THROUGH CENTRAL IOWA INTO SOUTHEAST IOWA WAS MOVING NORTHEAST AROUND 35 MPH. THIS LINE WILL BE CAPABLE OF PRODUCING DOWNBURST WINDS TO 70 MPH...HAIL TO ONE INCH IN DIAMETER AND VERY HEAVY RAIN IN LOCALIZED AREAS. ADDITIONAL THUNDERSTORM REDEVELOPMENT IS LIKELY THIS AFTERNOON AS A COLD FRONT OVER CENTRAL NEBRASKA MOVES INTO IOWA. ABUNDANT LOW LEVEL MOISTURE WILL STILL BE IN PLACE FOR THUNDERSTORM DEVELOPMENT. ADDITIONALLY... RIVERS CONTINUE TO RUN HIGH OVER THE STATE AND THE GROUND IS NEARLY SATURATED. SO ALTHOUGH THE STORMS SHOULD MOVE QUICKLY TO THE EAST THIS MORNING AND AFTERNOON...LOCALIZED HEAVY RAINS COULD CAUSE STREET FLOODING...SMALL STREAMS AND DITCHES WILL QUICKLY RISE SINCE COPIOUS QUANTITIES OF WATER HAVE RECENTLY FALLEN OVER IOWA. A FLASH FLOOD WATCH REMAINS IN EFFECT FOR ALL OF CENTRAL AND EASTERN IOWA TODAY. PRECAUTIONS--SPOTTER ACTIVATION MAY BE REQUIRED LATER THIS MORNING AND AFTERNOON TO REPORT WIND SPEEDS...HAIL SIZE...AND RAINFALL AMOUNTS. A FLASH FLOOD WATCH MEANS RAPIDLY RISING WATER OR FLOODING IS POSSIBLE WITHIN THE WATCH AREA. IF YOU ARE IN THE WATCH AREA...CHECK PREPAREDNESS REQUIREMENTS...KEEP INFORMED...AND BE READY FOR QUICK ACTION IF FLASH FLOODING IS OBSERVED OR IF A WARNING IS ISSUED. SEARCY
Special weather statement, Jun 18, 5:21 AM CDT, 5 hours 33 minutes before
IAZ044-181125- SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE DES MOINES IA 521 AM CDT THU JUN 18 1998 ...SEVERE THUNDERSTORM WATCH 602 HAS BEEN CANCELLED... SEVERE WEATHER WAS NO LONGER EXPECTED OVER WESTERN IOWA THROUGH 600 AM. THEREFORE THE SEVERE THUNDERSTORM WATCH THAT WAS IN EFFECT UNTIL 600 AM HAS BEEN CANCELLED. HOWEVER...ADDITIONAL THUNDERSTORMS WILL LIKELY REDEVELOP LATER TODAY AHEAD OF AN EASTWARD MOVING COLD FRONT THAT IS OVER CENTRAL AND EASTERN NEBRASKA EARLY THIS MORNING. ADDITIONALLY...A FLASH FLOOD WATCH REMAINS IN EFFECT FOR OF CENTRAL AND EASTERN IOWA...INCLUDING CRAWFORD COUNTY. KEEP AN EYE TO THE SKY TODAY AS THE WEATHER COULD BECOME ACTIVE ONCE AGAIN. SEARCY
Special weather statement, Jun 18, 5:34 AM CDT, 5 hours 20 minutes before
IAZ016-017-025-026-036-037-048-181234- SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE DES MOINES IA 534 AM CDT THU JUN 18 1998 DOPPLER RADAR IS INDICATING AN AREA OF STRONG WINDS FROM NORTH OF AMES TOWARDS MASON CITY ASSOCIATED WITH A LINE OF THUNDERSTORMS. WIND GUSTS COULD REACH JUST BELOW SEVERE LIMITS...WITH GUSTS TO 50 MPH POSSIBLE. THE STRONG WINDS WILL PUSH TOWARDS A CHARLES CITY TO WATERLOO LINE OVER THE NEXT HOUR. MYERS
Special weather statement, Jun 18, 9:31 AM CDT, 1 hour 23 minutes before
IAZ004>007-015>017-023>028-033>039-044>050-057>062-070>075-081>086- 092>097-182200- CENTRAL IOWA THUNDERSTORM OUTLOOK NATIONAL WEATHER SERVICE DES MOINES IA 931 AM CDT THU JUN 18 1998 HAZARD--SEVERE THUNDERSTORMS WITH HAIL 1 INCH OR LARGER... HEAVY RAINS AND DAMAGING WINDS. AN ISOLATED TORNADO IS ALSO POSSIBLE. AREA OF CONCERN AND TIMING DETAILS-- THROUGH NOON--ALONG AND EAST OF A FORT DODGE-ATLANTIC LINE. NOON TO 800 PM--MAINLY SOUTHEAST OF A FORT DODGE--CRESTON LINE. METEOROLOGICAL COMMENTS--A COLD FRONT WILL BE THE FOCUS OF THUNDERSTORM DEVELOPMENT THROUGH THE DAY. AT 900 AM...THE FRONT WAS LOCATED FROM NEAR SIOUX CITY TO JUST SOUTH OF OMAHA INTO SOUTH CENTRAL KANSAS. A WARM FRONT LOCATED NEAR I-80 WILL ALSO MOVE NORTH TODAY PROVIDING ANOTHER FOCUS FOR CONVERGENCE. WARM...UNSTABLE AND VERY MOIST AIR SOUTH OF THIS FRONT AND IS EXPECTED TO PROVIDE PLENTY OF BUOYANCY FOR STRONG UPDRAFTS FOR SEVERE THUNDERSTORMS TODAY. A 100 KNOT SOUTHWESTERLY JET STREAM WILL BE PUSHING NORTHEAST FROM THE TEXAS PANHANDLE TODAY INTERSECTING 40 KNOT SOUTHERLY FLOW IN THE LOWEST 5000 FEET. THIS WILL CREATE FAVORABLE SHEAR FOR THE MAINTENANCE OF ROTATING UPDRAFTS AND SEVERE STORMS. ISOLATED SUPERCELLS ARE POSSIBLE...BUT AT THIS TIME A SQUALL LINE IS EXPECTED TO FORM EVENTUALLY ALONG THE COLD FRONT THIS AFTERNOON...SPREADING EASTWARD TOWARD EVENING. PRECAUTIONS--EMERGENCY MANAGEMENT SHOULD PAY CLOSE ATTENTION TO SHORT TERM FORECASTS AND FURTHER STATEMENTS TODAY. SEVERE WEATHER WATCHES MAY BE ISSUED LATER THIS MORNING OR EARLY AFTERNOON. SPOTTER ACTIVATION WILL BE REQUIRED IN SEVERAL LOCATIONS. REPORT RAINFALL AMOUNTS TO THE NATIONAL WEATHER SERVICE IF AVAILABLE. A FLASH FLOOD WATCH IS IN EFFECT TODAY. KULA
Special weather statement, Jun 18, 9:31 AM CDT, 1 hour 23 minutes before
IAZ004>007-015>017-023>028-033>039-044>050-057>062-070>075-081>086- 092>097-182200- CENTRAL IOWA THUNDERSTORM OUTLOOK NATIONAL WEATHER SERVICE DES MOINES IA 931 AM CDT THU JUN 18 1998 HAZARD--SEVERE THUNDERSTORMS WITH HAIL 1 INCH OR LARGER... HEAVY RAINS AND DAMAGING WINDS. AN ISOLATED TORNADO IS ALSO POSSIBLE. AREA OF CONCERN AND TIMING DETAILS-- THROUGH NOON--ALONG AND EAST OF A FORT DODGE-ATLANTIC LINE. NOON TO 800 PM--MAINLY SOUTHEAST OF A FORT DODGE--CRESTON LINE. METEOROLOGICAL COMMENTS--A COLD FRONT WILL BE THE FOCUS OF THUNDERSTORM DEVELOPMENT THROUGH THE DAY. AT 900 AM...THE FRONT WAS LOCATED FROM NEAR SIOUX CITY TO JUST SOUTH OF OMAHA INTO SOUTH CENTRAL KANSAS. A WARM FRONT LOCATED NEAR I-80 WILL ALSO MOVE NORTH TODAY PROVIDING ANOTHER FOCUS FOR CONVERGENCE. WARM...UNSTABLE AND VERY MOIST AIR SOUTH OF THIS FRONT AND IS EXPECTED TO PROVIDE PLENTY OF BUOYANCY FOR STRONG UPDRAFTS FOR SEVERE THUNDERSTORMS TODAY. A 100 KNOT SOUTHWESTERLY JET STREAM WILL BE PUSHING NORTHEAST FROM THE TEXAS PANHANDLE TODAY INTERSECTING 40 KNOT SOUTHERLY FLOW IN THE LOWEST 5000 FEET. THIS WILL CREATE FAVORABLE SHEAR FOR THE MAINTENANCE OF ROTATING UPDRAFTS AND SEVERE STORMS. ISOLATED SUPERCELLS ARE POSSIBLE...BUT AT THIS TIME A SQUALL LINE IS EXPECTED TO FORM EVENTUALLY ALONG THE COLD FRONT THIS AFTERNOON...SPREADING EASTWARD TOWARD EVENING. PRECAUTIONS--EMERGENCY MANAGEMENT SHOULD PAY CLOSE ATTENTION TO SHORT TERM FORECASTS AND FURTHER STATEMENTS TODAY. SEVERE WEATHER WATCHES MAY BE ISSUED LATER THIS MORNING OR EARLY AFTERNOON. SPOTTER ACTIVATION WILL BE REQUIRED IN SEVERAL LOCATIONS. REPORT RAINFALL AMOUNTS TO THE NATIONAL WEATHER SERVICE IF AVAILABLE. A FLASH FLOOD WATCH IS IN EFFECT TODAY. KULA
Local storm report, Jun 18, 9:57 AM CDT, 57 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE DES MOINES IA
957 AM CDT THU JUN 18 1998
TIME(CDT) .....CITY LOCATION..... STATE ...EVENT/REMARKS...
....COUNTY LOCATION....
0800 AM CORYDON IA WIND DAMAGE
06/18/98 WAYNE UTILITY POLES AND TREES
DOWN, STRONG WINDSThe office that day
Everything else NWS Des Moines, IA issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jun 18, 3:35 AM CDT | Severe Thunderstorm Warning | DMX | Emmet | 30 min |
| Jun 18, 9:12 AM CDT | Severe Thunderstorm Warning | DMX | Adair, Cass, Guthrie | 33 min |
| Jun 18, 10:05 AM CDT | Severe Thunderstorm Warning | DMX | Webster | 35 min |
| Jun 18, 10:41 AM CDT | Severe Thunderstorm Warning | DMX | Marion | 34 min |
| Jun 18, 10:45 AM CDT | Severe Thunderstorm Warning | DMX | Boone, Webster | 35 min |
| Jun 18, 11:06 AM CDT | Severe Thunderstorm Warning | DMX | Jasper | 34 min |
| Jun 18, 11:12 AM CDT | Severe Thunderstorm Warning | DMX | Warren | 33 min |
| Jun 18, 11:15 AM CDT | Severe Thunderstorm Warning | DMX | Marshall, Story | 35 min |
| Jun 18, 11:21 AM CDT | Severe Thunderstorm Warning | DMX | Marion | 34 min |
| Jun 18, 11:22 AM CDT | Severe Thunderstorm Warning | DMX | Polk | 33 min |
| Jun 18, 11:36 AM CDT | Severe Thunderstorm Warning | DMX | Jasper | 34 min |
| Jun 18, 11:40 AM CDT | Severe Thunderstorm Warning | DMX | Boone | 35 min |
| Jun 18, 11:43 AM CDT | Severe Thunderstorm Warning | DMX | Hardin | 32 min |
| Jun 18, 11:50 AM CDT | Severe Thunderstorm Warning | DMX | Marshall, Story | 30 min |
| Jun 18, 12:01 PM CDT | Severe Thunderstorm Warning | DMX | Hamilton, Webster | 34 min |
| Jun 18, 12:55 PM CDT | Severe Thunderstorm Warning | DMX | Winnebago, Worth | 30 min |
| Jun 18, 1:30 PM CDT | Severe Thunderstorm Warning | DMX | Dallas, Polk | 35 min |
| Jun 18, 1:33 PM CDT | Severe Thunderstorm Warning | DMX | Union | 32 min |
| Jun 18, 1:56 PM CDT | Tornado Warning | DMX | Warren | 34 min |
| Jun 18, 1:59 PM CDT | Flash Flood Warning | DMX | Dallas | 3 hr |
| Jun 18, 2:09 PM CDT | Severe Thunderstorm Warning | DMX | Polk | 31 min |
| Jun 18, 2:16 PM CDT | Flash Flood Warning | DMX | Polk | 3 hr |
| Jun 18, 2:16 PM CDT | Tornado Warning | DMX | Polk | 34 min |
| Jun 18, 2:19 PM CDT | Flash Flood Warning | DMX | Story | 3 hr |
| Jun 18, 2:35 PM CDT | Flash Flood Warning | DMX | Madison | 3 hr |
| Jun 18, 3:03 PM CDT | Severe Thunderstorm Warning | DMX | Mahaska, Marion | 32 min |
| Jun 18, 3:12 PM CDT | Severe Thunderstorm Warning | DMX | Poweshiek | 28 min |
| Jun 18, 3:16 PM CDT | Severe Thunderstorm Warning | DMX | Black Hawk, Tama | 34 min |
| Jun 18, 3:34 PM CDT | Severe Thunderstorm Warning | DMX | Davis, Wapello | 31 min |
| Jun 18, 5:04 PM CDT | Flash Flood Warning | DMX | Polk, Story | 2 hr |
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; radar from the NEXRAD Level II archive.