Alert archive / Iowa / Flash Flood Warnings in 1998

Flash Flood Warning 9, NWS Des Moines, IA

June 18, 1998Story County, Iowa

NWS Des Moines, IA issued this flash flood warning at Jun 18, 1998, 2:19 PM CDT for Story 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, 2:19 PM CDT (19:19 UTC)
Expired
Jun 18, 1998, 5:30 PM CDT
In force
3 hr
Issued by
NWS Des Moines, IA
Area
Whole counties

County Story County, IA

The radar

The Des Moines radar (KDMX), 40 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

Davenport, (KDVN), launched 12:00Z, 7.3 hours before the alert went out and 250 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 1998-06-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2000 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 1998-06-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 112 square meters per square second.193958Sfc1 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
2000 J/kg
Mixed-layer CIN
-220 J/kg
Mixed-layer LCL
1205 m above ground
0-6 km bulk shear
25 kt
0-1 km storm-relative helicity
112 m²/s²
0-3 km storm-relative helicity
81 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.

000 
TTAA00 KDSM 181918
FFWDSM
IAC169-182220-

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE DES MOINES IA
219 PM CDT THU JUN 18 1998

THE NATIONAL WEATHER SERVICE IN DES MOINES HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  STORY 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 STORY AND POLK COUNTIES...
  MOVING NORTHEAST AT 35 MPH.

* WIDESPREAD HEAVY RAINS OF 2 TO 4 INCHES OR ISOLATED HIGHER AMOUNTS
  WILL CAUSE RAPID RISES WITH CREEKS AND STREAMS TO OVERFLOW THEIR
  BANKS.

SOME STREAMS AFFECTED INCLUDE...
  SQUAW CREEK
  BEAR CREEK
  INDIAN CREEK

MOVE TO HIGHER GROUNnD IF FLOOD WATERS THREATEN.

FORSTER

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, 2:35 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
Jun 18, 5:04 PM CDTFlash Flood WarningDMXPolk, Story2 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.