Alert archive / Iowa / Flash Flood Warnings in 1998

Flash Flood Warning 7, NWS Des Moines, IA

June 18, 1998Dallas County, Iowa

NWS Des Moines, IA issued this flash flood warning at Jun 18, 1998, 1:59 PM CDT for Dallas 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, 1:59 PM CDT (18:59 UTC)
Expired: Jun 18, 1998, 5:00 PM CDT
In force: 3 hr
Issued by: NWS Des Moines, IA
Area: Whole counties

County Dallas County, IA

The radar

The Des Moines radar (KDMX), 27 km from the middle of the area, began a volume at 18:59 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, 7.0 hours before the alert went out and 198 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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 181858
FFWDSM
IAC049-182200-

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

THE NATIONAL WEATHER SERVICE IN DES MOINES HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  DALLAS COUNTY IN CENTRAL IOWA

* UNTIL 500 PM CDT

* AT 150 PM CDT... SPOTTERS INDICATED A THUNDERSTORM WITH VERY HEAVY
  RAIN IN DALLAS COUNTY... MOVING NORTHEAST AT 35 MPH.

* CONTINUED HEAVY RAINS OVER DALLAS COUNTY WITH MORE STORMS EXPECTED
  WILL CAUSE WIDEPSREAD FLOODING AND RIVERS AND STREAMS TO OVERFLOW
  THEIR BANKS.

SOME STREAMS AFFECTED INCLUDE...
  NORTHERN REACHES OF WALNUT CREEK
  PANTHER CREEK
  BEAVER CREEK
  MOSQUITO CREEK

MOVE TO HIGHER GROUND IF FLOOD WATERS THREATEN.

FORSTER

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, 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

Flash Flood Warnings in Iowa, 1998 Every 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.