Alert archive / Iowa / Flash Flood Warnings in 1997

Flash Flood Warning 4, NWS Des Moines, IA

July 19, 1997Kossuth County, Iowa

NWS Des Moines, IA issued this flash flood warning at Jul 19, 1997, 9:30 PM CDT for Kossuth 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
Jul 19, 1997, 9:30 PM CDT (02:30 UTC)
Expired
Jul 20, 1997, 12:30 AM CDT
In force
3 hr
Issued by
NWS Des Moines, IA
Area
Whole counties

County Kossuth County, IA

The radar

The Des Moines radar (KDMX), 169 km from the middle of the area, began a volume at 02:33 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 00:00Z, 2.5 hours before the alert went out and 189 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 00:00Z on 1997-07-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 726 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Minneapolis, MN at 00:00Z on 1997-07-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 147 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
726 J/kg
Mixed-layer CIN
-170 J/kg
Mixed-layer LCL
621 m above ground
0-6 km bulk shear
31 kt
0-1 km storm-relative helicity
147 m²/s²
0-3 km storm-relative helicity
176 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.3

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KDSM 200230
FFWDSM
IAC109-200530-

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE DES MOINES IA
930 PM CDT SAT JUL 19 1997

* FLASH FLOOD WARNING FOR
  CENTRAL AND NORTHERN KOSSUTH COUNTY - NORTH CENTRAL IOWA

* UNTIL 1230 AM CDT
 
* SOME STREAMS AFFECTED
    DES MOINES RIVER
    BUFFALO CREEK
    BLACK CAT CREEK
    LINDSEY CREEK

* CAUSE AND EFFECT
    PERSISTENT THUNDERSTORMS CROSSING NORTHERN AND CENTRAL KOSSUTH
    COUNTY WILL CONTINUE TO PRODUCE 1 TO 2 INCHES OF RAIN PER HOUR.

* FORECAST CONDITIONS
    ADDITIONAL RAINFALL THROUGH MIDNIGHT OF 2 TO 4 INCHES IS LIKELY.

LEAVE FLOOD PRONE OR LOW LYING AREAS IMMEDIATELY.  NEVER DRIVE INTO
STANDING WATER.

KUBINA

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, Jul 19, 5:08 PM CDT, 4 hours 22 minutes before
IAZ004>007-015>017-023>028-033>039-044>050-057>062-070>075-081>086-
092>097-200410-

CENTRAL IOWA THUNDERSTORM OUTLOOK
NATIONAL WEATHER SERVICE DES MOINES IA
508 PM CDT SAT JUL 19 1997

HAZARD--WIDELY SCATTERED THUNDERSTORMS THIS EVENING CAPABLE OF
PRODUCING TORRENTIAL RAINFALL OF FROM 2 TO 3 INCHES IN AN HOURS TIME
ALONG WITH THE POTENTIAL FOR HAIL. ADDITIONAL THUNDERSTORM
DEVELOPMENT EXPECTED LATER TONIGHT.

AREA OF CONCERN--FAR EASTERN PORTION OF THE WARNING AREA...ALONG
AND EAST OF AN OTTUMWA TO WATERLOO LINE. LATE TONIGHT THE THREAT WILL
SHIFT INTO THE NORTHERN QUARTER OF THE STATE...NORTH OF HIGHWAY 20.

TIMING DETAILS--THROUGH 700 PM OVER THE FAR EASTERN WARNING AREA
WITH ADDITIONAL THUNDERSTORMS PUSHING INTO NORTHERN IOWA AFTER
MIDNIGHT.

METEOROLOGICAL COMMENTS--A RATHER DISTINCT FRONTAL BOUNDARY WAS
LOCATED OVER NORTH CENTRAL THROUGH EASTERN IOWA THIS EVENING.
TEMPERATURES TO THE EAST OF THE BOUNDARY WERE IN THE MID 60S WHILE
READINGS WEST OF THE FRONT WERE IN THE 90S. THIS TEMPERATURE
DISCONTINUITY IS HELPING FUEL WIDELY SCATTERED THUNDERSTORMS ACROSS
THE FAR EASTERN WARNING AREA WITH THE PRIMARY THREAT FROM THESE
STORMS BEING VERY HEAVY RAINFALL AND LARGE HAIL. LATER THIS EVENING
AS THE THERMAL BOUNDARY WEAKENS...THE THUNDERSTORM THREAT WILL
GRADUALLY DIMINISH.

LATER TONIGHT...A NEW THUNDERSTORM COMPLEX IS FORECAST TO DEVELOP
ACROSS THE DAKOTAS AND MINNESOTA WITH MOVEMENT INTO EXTREME NORTHERN
IOWA AFTER MIDNIGHT. SOUTHERLY WINDS AT THE LOW LEVELS ARE FORECAST
TO INCREASE AFTER DARK TRANSPORTING COPIOUS AMOUNTS OF MOISTURE
NORTHWARD INTO THE STATE. WITH THE FRONTAL BOUNDARY FORECAST TO BE
ACROSS NORTHERN AND EASTERN IOWA OVERNIGHT...THE PRIMARY AREA OF
CONCERN WOULD BE NORTH OF HIGHWAY 20. PRECIPITABLE WATER VALUES ARE
WELL ABOVE NORMAL FOR THIS TIME OF YEAR INDICATING A REAL THREAT FOR
SIGNIFICANT RAINFALL IN AREAS THAT DO SEE THE THUNDERSTORMS LATER
TONIGHT.

PRECAUTIONS--SPOTTER ACTIVATION APPEARS UNLIKELY THIS EVENING. KEEP
ABREAST OF LATER SHORT TERM FORECASTS AND CENTRAL IOWA THUNDERSTORM
OUTLOOKS THIS EVENING.

SMITH

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 20, 2:59 PM CDTSevere Thunderstorm WarningDMXPolk31 min
Jul 20, 4:50 PM CDTSevere Thunderstorm WarningDMXMonroe35 min

Nearby

Flash Flood Warnings in Iowa, 1997Every flash flood warning in 1997

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.