Alert archive / Iowa / Flash Flood Warnings in 1998

Flash Flood Warning 11, NWS Des Moines, IA

June 18, 1998Polk County, Story County, Iowa

NWS Des Moines, IA issued this flash flood warning at Jun 18, 1998, 5:04 PM CDT for Polk County, Story County, Iowa. It was in force for 2 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, 5:04 PM CDT (22:04 UTC)
Expired
Jun 18, 1998, 7:05 PM CDT
In force
2 hr
Issued by
NWS Des Moines, IA
Area
Whole counties

Counties Polk County, IA, Story County, IA

The radar

The Des Moines radar (KDMX), 22 km from the middle of the area, began a volume at 22:04 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, 10.1 hours before the alert went out and 245 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 12:00Z on 1998-06-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 245 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 12:00Z on 1998-06-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -105 square meters per square second.19395878Sfc1 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
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

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KDSM 182204
FFWDSM
IAC153-169-190005-

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE DES MOINES IA
504 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
  STORY COUNTY IN CENTRAL IOWA

* UNTIL 705 PM CDT

* AT BETWEEN 800 AM AND 300 PM CDT.... NATIONAL WEATHER SERVICE
  DOPPLER RADAR INDICATED THUNDERSTORMS WITH VERY HEAVY RAIN
  MOVED THROUGH POLK AND STORY COUNTIES.

* STRONG THUNDERSTORMS THAT PRODUCE RAINFALL IN STORY AND POLK
  COUNTIES HAVE CAUSED WIDESPREAD URBAN FLOODING AS WELL AS
  CAUSING STREAMS TO OVERFLOW THEIR BANKS.

SOME STREAMS AFFECTED INCLUDE...
  WALNUT CREEK
  FOUR MILE CREEK
  JORDAN CREEK

DON'T DRIVE INTO AREAS WHERE WATER COVERS THE ROAD!

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, 12:59 PM CDT, 4 hours 5 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
Local storm report, Jun 18, 5:01 PM CDT, 3 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE DES MOINES IA
501 PM 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 WINDS

1000 AM    GOWRIE                    IA   .75 INCH HAIL
06/18/98   WEBSTER

1004 AM    2 SE CALLENDER            IA   .75 INCH HAIL
06/18/98   WEBSTER

1015 AM    1 S FT DODGE              IA   .75 INCH HAIL
06/18/98   WEBSTER

1032 AM    EARLHAM                   IA   1 INCH HAIL
06/18/98   MADISON

1043 AM    3 NW BOONE                IA   1.75 INCH HAIL
06/18/98   BOONE

1052 AM    MELCHER                   IA   WIND DAMAGE
06/18/98   MARION                         LARGE TREE LIMBS DOWN

1055 AM    2 NE BOXHOLM              IA   .75 INCH HAIL
06/18/98   BOONE

1058 AM    2 SW DAYTON               IA   .75 INCH HAIL
06/18/98   WEBSTER

1102 AM    ALTOONA                   IA   WIND DAMAGE
06/18/98   POLK                           LARGE TREE LIMBS DOWN

1103 AM    KNOXVILLE                 IA   .75 INCH HAIL
06/18/98   MARION

1113 AM    DES MOINES                IA   WIND DAMAGE
06/18/98   POLK                           ROOF TORN OFF HOUSE

1120 AM    URBANDALE                 IA   WIND DAMAGE
06/18/98   POLK                           LARGE TREE DOWN

1122 AM    CARLISLE                  IA   WIND DAMAGE
06/18/98   WARREN                         TREES AND POWER LINES DOWN

1124 AM    ALTOONA                   IA   WIND DAMAGE
06/18/98   POLK                           POWER LINES DOWN

1138 AM    WEST DES MOINES           IA   WIND DAMAGE
06/18/98   POLK                           ROOF OFF BUILDING TREES
                                          DOWN

1141 AM    HUXLEY                    IA   75 MPH TSTM GUST
06/18/98   STORY                          TREES DOWN

1151 AM    URBANDALE                 IA   WIND DAMAGE
06/18/98   POLK                           1 FOOT DIAMETER TREE DOWN

1155 AM    BOONE                     IA   60 MPH TSTM GUST
06/18/98   BOONE

1158 AM    MILO                      IA   WIND DAMAGE
06/18/98   WARREN                         TREES AND POWER LINES DOWN

The office that day

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

IssuedProductOfficeCountiesLasted
Jun 18, 3:35 AM CDTSevere Thunderstorm WarningDMXEmmet30 min
Jun 18, 9:12 AM CDTSevere Thunderstorm WarningDMXAdair, Cass, Guthrie33 min
Jun 18, 10:05 AM CDTSevere Thunderstorm WarningDMXWebster35 min
Jun 18, 10:41 AM CDTSevere Thunderstorm WarningDMXMarion34 min
Jun 18, 10:45 AM CDTSevere Thunderstorm WarningDMXBoone, Webster35 min
Jun 18, 10:54 AM CDTSevere Thunderstorm WarningDMXPolk31 min
Jun 18, 11:06 AM CDTSevere Thunderstorm WarningDMXJasper34 min
Jun 18, 11:12 AM CDTSevere Thunderstorm WarningDMXWarren33 min
Jun 18, 11:15 AM CDTSevere Thunderstorm WarningDMXMarshall, Story35 min
Jun 18, 11:21 AM CDTSevere Thunderstorm WarningDMXMarion34 min
Jun 18, 11:22 AM CDTSevere Thunderstorm WarningDMXPolk33 min
Jun 18, 11:36 AM CDTSevere Thunderstorm WarningDMXJasper34 min
Jun 18, 11:40 AM CDTSevere Thunderstorm WarningDMXBoone35 min
Jun 18, 11:43 AM CDTSevere Thunderstorm WarningDMXHardin32 min
Jun 18, 11:50 AM CDTSevere Thunderstorm WarningDMXMarshall, Story30 min
Jun 18, 12:01 PM CDTSevere Thunderstorm WarningDMXHamilton, Webster34 min
Jun 18, 12:55 PM CDTSevere Thunderstorm WarningDMXWinnebago, Worth30 min
Jun 18, 1:30 PM CDTSevere Thunderstorm WarningDMXDallas, Polk35 min
Jun 18, 1:33 PM CDTSevere Thunderstorm WarningDMXUnion32 min
Jun 18, 1:56 PM CDTTornado WarningDMXWarren34 min
Jun 18, 1:59 PM CDTFlash Flood WarningDMXDallas3 hr
Jun 18, 2:09 PM CDTSevere Thunderstorm WarningDMXPolk31 min
Jun 18, 2:16 PM CDTFlash Flood WarningDMXPolk3 hr
Jun 18, 2:16 PM CDTTornado WarningDMXPolk34 min
Jun 18, 2:19 PM CDTFlash Flood WarningDMXStory3 hr
Jun 18, 2:35 PM CDTFlash Flood WarningDMXMadison3 hr
Jun 18, 3:03 PM CDTSevere Thunderstorm WarningDMXMahaska, Marion32 min
Jun 18, 3:12 PM CDTSevere Thunderstorm WarningDMXPoweshiek28 min
Jun 18, 3:16 PM CDTSevere Thunderstorm WarningDMXBlack Hawk, Tama34 min
Jun 18, 3:34 PM CDTSevere Thunderstorm WarningDMXDavis, Wapello31 min

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.