Alert archive / Iowa / Flash Flood Warnings in 1998

Flash Flood Warning 6, NWS Des Moines, IA

June 15, 1998Hancock County, Iowa

NWS Des Moines, IA issued this flash flood warning at Jun 15, 1998, 2:11 PM CDT for Hancock 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 15, 1998, 2:11 PM CDT (19:11 UTC)
Expired
Jun 15, 1998, 5:10 PM CDT
In force
3 hr
Issued by
NWS Des Moines, IA
Area
Whole counties

County Hancock County, IA

The radar

The Des Moines radar (KDMX), 150 km from the middle of the area, began a volume at 19:11 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

Minneapolis, MN (KMPX), launched 12:00Z, 7.2 hours before the alert went out and 197 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, Minneapolis, MN at 12:00Z on 1998-06-15Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 454 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, Minneapolis, MN at 12:00Z on 1998-06-15The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 6 square meters per square second.1939Sfc1 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
454 J/kg
Mixed-layer CIN
-42 J/kg
Mixed-layer LCL
1046 m above ground
0-6 km bulk shear
4 kt
0-1 km storm-relative helicity
6 m²/s²
0-3 km storm-relative helicity
52 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 151911
FFWDSM
IAC081-152210-

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE DES MOINES IA
211 PM CDT MON JUN 15 1998

THE NATIONAL WEATHER SERVICE IN DES MOINES HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  SOUTHERN HANCOCK COUNTY IN NORTH CENTRAL IOWA

* UNTIL 510 PM CDT

* AT 205 PM CDT... NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  THUNDERSTORM WITH VERY HEAVY RAIN 5 MILES SOUTH OF BRITT OR 25
  MILES SOUTHWEST OF MASON CITY. THE STORM WAS STATIONARY.

* DOPPLER RADAR INDICATED OVER 6 INCHES OF RAIN BETWEEN BRITT AND
  KANAWHA BETWEEN NOON AND 2 PM.  IN ADDITION...HANCOCK COUNTY
  SHERIFF'S REPORTED ROADS BEING FLOODED SOUTH OF BRITT.

SOME STREAMS AFFECTED INCLUDE...
  MIDDLE BRANCH OF BOONE RIVER
  EAST BRANCH OF BOONE RIVER
  WEST BRANCH OF THE IOWA RIVER
  OTTER CREEK

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

THIS REPLACES THE URBAN AND SMALL STREAM FLOOD ADVISORY.

JOHNSONZ

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 15, 1:20 PM CDT, 51 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
120 PM CDT MON JUN 15 1998

IAZ016-152021-
HANCOCK-
120 PM CDT MON JUN 15 1998

AN ISOLATED STORM JUST SOUTH OF BRITT IN HANCOCK COUNTY WAS SHOWING
VERY LITTLE IF ANY MOVEMENT.  DOPPLAR RADAR INDICATED RAINFALL OF 2.5
TO 3.0 INCHES FALLING A SMALL AREA OF THE COUNTY NEAR THE WEST FORK
OF THE IOWA RIVER.

PEOPLE IN THIS AREA SHOULD REMAIN ALERT FOR ANY WATER OVER ROADS OR
RAPIDLY-RISING SMALL CREEKS OR STREAMS IN THE AREA.

FORSTER
Special weather statement, Jun 15, 1:20 PM CDT, 51 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
120 PM CDT MON JUN 15 1998

IAZ016-152021-
HANCOCK-
120 PM CDT MON JUN 15 1998

AN ISOLATED STORM JUST SOUTH OF BRITT IN HANCOCK COUNTY WAS SHOWING
VERY LITTLE IF ANY MOVEMENT.  DOPPLAR RADAR INDICATED RAINFALL OF 2.5
TO 3.0 INCHES FALLING A SMALL AREA OF THE COUNTY NEAR THE WEST FORK
OF THE IOWA RIVER.

PEOPLE IN THIS AREA SHOULD REMAIN ALERT FOR ANY WATER OVER ROADS OR
RAPIDLY-RISING SMALL CREEKS OR STREAMS IN THE AREA.

FORSTER

The office that day

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

IssuedProductOfficeCountiesLasted
Jun 15, 5:43 AM CDTFlash Flood WarningDMXCass10 hr
Jun 15, 10:15 AM CDTFlash Flood WarningDMXCass6 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.