Alert archive / Iowa / Flash Flood Warnings in 1998
Flash Flood Warning 8, NWS Des Moines, IA
NWS Des Moines, IA issued this flash flood warning at Jun 18, 1998, 2:16 PM CDT for Polk County, Iowa. It was in force for 3 hr. No storm report in the archive falls inside the area while it was in force.
The area
The counties it named.
The facts
- Issued
- Jun 18, 1998, 2:16 PM CDT (19:16 UTC)
- Expired
- Jun 18, 1998, 5:30 PM CDT
- In force
- 3 hr
- 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 19:19 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 nearest sounding before it
Omaha, NE (KOAX), launched 12:00Z, 7.3 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.
000 TTAA00 KDSM 181915 FFWDSM IAC153-182220- BULLETIN - EAS ACTIVATION REQUESTED FLASH FLOOD WARNING NATIONAL WEATHER SERVICE DES MOINES IA 216 PM CDT THU JUN 18 1998 THE NATIONAL WEATHER SERVICE IN DES MOINES HAS ISSUED A * FLASH FLOOD WARNING FOR... POLK COUNTY IN CENTRAL IOWA * UNTIL 530 PM CDT * AT 200 PM CDT... NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A THUNDERSTORM WITH VERY HEAVY RAIN OVER POLK COUNTY... MOVING NORTHEAST AT 35 MPH WITH MORE STORMS MOVING INTO THE AREA. * HEAVY RAINS OF 2 TO 5 INCHES WITH MORE RAIN OCCURRING AT THIS TIME WILL CONTINUE WILL CAUSE WIDESPREAD FLOODING AND THE RAPID RISE OF CREEKS AND STREAMS. SOME STREAMS AFFECTED INCLUDE... JORDAN CREEK WALNUT CR`EEK FOUR MILE CREEK MOVE TO HIGHER GROUND IF FLOOD WATERS THREATEN. FORSTER
What forecasters said that day
The local office's own words before this flash flood 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, 9:31 AM CDT, 4 hours 45 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, 4 hours 45 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, 4 hours 19 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 WINDSSpecial weather statement, Jun 18, 12:59 PM CDT, 1 hour 17 minutes before
IAZ004>007-015>017-023>028-033>039-044>050-057>062-070>075-081>086- 092>097-190100- CENTRAL IOWA THUNDERSTORM OUTLOOK NATIONAL WEATHER SERVICE DES MOINES IA 1259 PM CDT THU JUN 18 1998 HAZARD--SEVERE THUNDERSTORMS WITH DAMAGING WINDS ABOVE 60 MPH...HAIL 1 INCH OR LARGER AND HEAVY RAINS. URBAN AND SMALL STREAM FLOODING IS LIKELY WITH THE HEAVIEST STORMS. AREA OF CONCERN AND TIMING DETAILS-- EAST OF A POCAHONTAS--AUDUBON--BEDFORD LINE...OR VIRTUALLY ALL OF CENTRAL INTO EASTERN IOWA FROM NOW UNTIL 600 PM. METEOROLOGICAL COMMENTS--A COLD FRONT WAS APPROACHING A STORM LAKE-- AUDUBON--SHENANDOAH LINE AND WILL PUSH EAST THIS AFTERNOON. THE FIRST ROUND OF STORMS WHICH PRODUCED SEVERE WEATHER IN CENTRAL IOWA WAS AFFECTING AREAS OF NORTH CENTRAL IOWA NORTH OF WEBSTER CITY UP TOWARDS MASON CITY. NEWER DEVELOPMENT WAS TAKING PLACE RAPIDLY IN CENTRAL AND SOUTH CENTRAL IOWA FROM BOONE THROUGH CRESTON. OTHER STORMS MOVING INTO TAYLOR AND RINGGOLD COUNTIES FROM MISSOURI WILL MOVE NORTHEAST AT 50 MPH ALSO. ANY ONE OF THESE STORMS IS CAPABLE OF SEVERE WEATHER. PRECAUTIONS--EMERGENCY MANAGEMENT SHOULD PAY CLOSE ATTENTION TO SHORT TERM FORECASTS AND FURTHER WARNINGS. SPOTTER ACTIVATION WILL BE REQUIRED IN SEVERAL LOCATIONS. REPORT RAINFALL AMOUNTS TO THE NATIONAL WEATHER SERVICE IF AVAILABLE. A FLASH FLOOD WATCH IS ALSO IN EFFECT TODAY. KULA
The 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, 10:54 AM CDT | Severe Thunderstorm Warning | DMX | Polk | 31 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 | 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
Flash Flood Warnings in Iowa, 1998Every flash flood 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.