Alert archive / Iowa / Flash Flood Warnings in 1996

Flash Flood Warning 7, NWS Sioux Falls, SD

July 17, 1996Woodbury County, Iowa; Dakota County, Nebraska

NWS Sioux Falls, SD issued this flash flood warning at Jul 17, 1996, 1:28 AM CDT for Woodbury County, Iowa; Dakota County, Nebraska. 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 17, 1996, 1:28 AM CDT (06:28 UTC)
Expired
Jul 17, 1996, 4:00 AM CDT
In force
3 hr
Issued by
NWS Sioux Falls, SD
Area
Whole counties

Counties Woodbury County, IA, Dakota County, NE

The nearest sounding before it

Omaha, NE (KOAX), launched 00:00Z, 6.5 hours before the alert went out and 119 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 00:00Z on 1996-07-17Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1921 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 00:00Z on 1996-07-17The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 101 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
1921 J/kg
Mixed-layer CIN
-74 J/kg
Mixed-layer LCL
979 m above ground
0-6 km bulk shear
30 kt
0-1 km storm-relative helicity
101 m²/s²
0-3 km storm-relative helicity
214 m²/s²
Significant tornado parameter
0.0
Supercell composite
3.5

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KFSD 170632 COR
FFWFSD
IAC193-NEC043-051-170900-

BULLETIN - EBS ACTIVATION REQUESTED
FLASH FLOOD WARNING...CORRECTED
NATIONAL WEATHER SERVICE SIOUX FALLS SD
128 AM CDT WED JUL 17 1996

THE NATIONAL WEATHER SERVICE IN SIOUX FALLS SD HAS ISSUED A
FLASH FLOOD WARNING EFFECTIVE UNTIL 400 AM CDT
FOR PEOPLE IN THE FOLLOWING COUNTY...

IN NORTHWEST IOWA

   ...WOODBURY COUNTY

IN NORTHEAST NEBRASKA

   ...DAKOTA COUNTY
   ...DIXON COUNTY

THIS FLASH FLOOD WARNING EXTENDS AND CONSOLIDATES THE PREVIOUS
FLASH FLOOD WARNINGS FOR THESE COUNTIES
 
AT 120 AM CDT...WIDESPREAD FLOODING CONTINUED ACROSS DIXON...
DAKOTA...AND WOODBURY COUNTIES...RESULTING FROM FIVE TO TEN INCHES
OF RAINFALL WHICH OCCURRED THIS EVENING.  AS OF 1 AM...8.32 INCHES
OF RAINFALL WAS REPORTED IN SOUTHEAST SIOUX CITY SINCE 7PM.

NUMEROUS ROADWAYS REMAIN FLOODED. OFFICIALS IN DAKOTA AND DIXON
COUNTIES WERE IN THE PROCESS OF RESCUING NUMEROUS INDIVIDUALS
STRANDED IN THEIR CARS BY RISING WATER.

THE CREEK RUNNING THROUGH JACKSON HAD REPORTEDLY CLIMBED OUT OF
ITS BANKS AROUND 1 AM. MANY CREEKS IN WOODBURY COUNTY WERE STILL
RISING.

 
DO NOT DRIVE YOUR VEHICLE INTO AREAS WHERE WATER COVERS THE
ROADWAY.  THE WATER DEPTH MAY BE TOO GREAT TO ALLOW YOUR CAR TO
CROSS SAFELY.  VEHICLES CAUGHT IN RISING WATER SHOULD BE ABANDONED
QUICKLY.  MOVE TO HIGHER GROUND.

CHAPMAN

&

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 16, 10:42 PM CDT, 2 hours 46 minutes before
TTAA00 KFSD DDHHMM
IAZ031-032-170600-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE SIOUX FALLS SD
1040 PM CDT TUE JUL 17 1996

...TORNADO WATCH 790 REPLACED BY SEVERE THUNDERSTORM WATCH 791...

THE TORNADO WATCH THAT WAS IN IN EFFECT UNTIL 1 AM FOR WOODBURY AND
IDA COUNTIES IN IOWA HAS BEEN REPLACED BY A SEVERE THUNDERSTORM WATCH
WHICH IS VALID UNTIL 4 AM CDT FOR MUCH OF SOUTHEAST SOUTH DAKOTA...
NORTHEAST NEBRASKA...AND NORTHWEST IOWA.

CHAPMAN

The office that day

Everything else NWS Sioux Falls, SD issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 16, 7:17 PM CDTSevere Thunderstorm WarningFSDWoodbury43 min
Jul 16, 8:02 PM CDTSevere Thunderstorm WarningFSDIda, Woodbury48 min
Jul 16, 10:24 PM CDTSevere Thunderstorm WarningFSDWoodbury31 min
Jul 16, 10:48 PM CDTFlash Flood WarningFSDWoodbury3 hr
Jul 16, 10:56 PM CDTSevere Thunderstorm WarningFSDWoodbury34 min
Jul 16, 11:36 PM CDTSevere Thunderstorm WarningFSDIda, Woodbury34 min
Jul 16, 7:04 PM CDTSevere Thunderstorm WarningFSDDakota31 min
Jul 16, 9:21 PM CDTSevere Thunderstorm WarningFSDDixon34 min
Jul 16, 9:55 PM CDTFlash Flood WarningFSDDixon35 min
Jul 16, 9:55 PM CDTSevere Thunderstorm WarningFSDDixon35 min
Jul 16, 10:13 PM CDTFlash Flood WarningFSDDakota, Dixon3 hr
Jul 16, 10:52 PM CDTSevere Thunderstorm WarningFSDDakota33 min
Jul 16, 11:31 PM CDTSevere Thunderstorm WarningFSDDixon34 min
Jul 17, 1:28 AM CDTFlash Flood WarningFSDDixon3 hr

Nearby

Flash Flood Warnings in Iowa, 1996Flash Flood Warnings in Nebraska, 1996Every flash flood warning in 1996

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.