Alert archive / Iowa / Flash Flood Warnings in 1999

Flash Flood Warning 2, NWS Sioux Falls, SD

June 5, 1999Sioux County, Iowa

NWS Sioux Falls, SD issued this flash flood warning at Jun 5, 1999, 7:12 PM CDT for Sioux 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 5, 1999, 7:12 PM CDT (00:12 UTC)
Expired
Jun 5, 1999, 10:05 PM CDT
In force
3 hr
Issued by
NWS Sioux Falls, SD
Area
Whole counties

County Sioux County, IA

The nearest sounding before it

Omaha, NE (KOAX), launched 00:00Z, 0.2 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, Omaha, NE at 00:00Z on 1999-06-06Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2262 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 1999-06-06The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 180 square meters per square second.19395878Sfc1 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
2262 J/kg
Mixed-layer CIN
-44 J/kg
Mixed-layer LCL
1299 m above ground
0-6 km bulk shear
38 kt
0-1 km storm-relative helicity
180 m²/s²
0-3 km storm-relative helicity
244 m²/s²
Significant tornado parameter
1.7
Supercell composite
12.0

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KFSD 060014
FFWFSD
IAC041-059-141-143-167-060305-

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE SIOUX FALLS SD
712 PM CDT SAT JUN 5 1999

THE NATIONAL WEATHER SERVICE IN SIOUX FALLS HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  CLAY COUNTY IN NORTHWESTERN IOWA
  DICKINSON COUNTY IN NORTHWESTERN IOWA
  O'BRIEN COUNTY IN NORTHWESTERN IOWA
  OSCEOLA COUNTY IN NORTHWESTERN IOWA
  SIOUX COUNTY IN NORTHWESTERN IOWA

* UNTIL 1005 PM CDT

* A SERIES OF THUNDERSTORMS HAVE BEEN MOVING NORTHEAST AT 40 MPH
ACROSS PARTS OF NORTHWEST IOWA THIS EVENING.  NATIONAL
WEATHER SERVICE DOPPLER RADAR INDICATED RAINFALL TOTALS OF 2 TO 3
INCHES FALLING IN A SHORT PERIOD OF TIME CAUSING PONDING AND
FLOODING OF LOW LYING AREAS.

THUNDERSTORMS WILL BE DIMINISHING OVER THE AREA BY 9 PM AND
CONDITIONS WILL GRADUALLY IMPROVE.

IT IS VERY DIFFICULT TO TELL HOW MUCH WATER IS ON ROADS. MOTORISTS
SHOULD NOT DRIVE THROUGH WATER OF UNKNOWN DEPTH.  SLOW DOWN OR PULL
OFF THE ROAD AND STOP WHEN VISIBILITY DROPS TO NEAR ZERO IN
TORRENTIAL DOWNPOURS.

ADU

The office that day

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

IssuedProductOfficeCountiesLasted
Jun 5, 7:12 PM CDTFlash Flood WarningFSDClay, Dickinson, O'Brien, Osceola3 hr

Nearby

Flash Flood Warnings in Iowa, 1999Every flash flood warning in 1999

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.