Alert archive / Iowa / Flash Flood Warnings in 1999
Flash Flood Warning 12, NWS Sioux Falls, SD
NWS Sioux Falls, SD issued this flash flood warning at Jul 18, 1999, 3:21 AM CDT for 4 counties in 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 18, 1999, 3:21 AM CDT (08:21 UTC)
- Expired
- Jul 18, 1999, 6:20 AM CDT
- In force
- 3 hr
- Issued by
- NWS Sioux Falls, SD
- Area
- Whole counties
Counties Buena Vista County, IA, Cherokee County, IA, Ida County, IA, Woodbury County, IA
The radar
The Sioux Falls radar (KFSD), 147 km from the middle of the area, began a volume at 08:25 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 00:00Z, 8.4 hours before the alert went out and 153 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.
- Mixed-layer CAPE
- 452 J/kg
- Mixed-layer CIN
- -9 J/kg
- Mixed-layer LCL
- 765 m above ground
- 0-6 km bulk shear
- 19 kt
- 0-1 km storm-relative helicity
- 45 m²/s²
- 0-3 km storm-relative helicity
- 273 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
000 TTAA00 KFSD 180830 COR FFWFSD IAC021-035-093-193-NEC043-181120- BULLETIN - IMMEDIATE BROADCAST REQUESTED URBAN FLOOD WARNING...CORRECTION TO MOVEMENT NATIONAL WEATHER SERVICE SIOUX FALLS SD 321 AM CDT SUN JUL 18 1999 THE NATIONAL WEATHER SERVICE IN SIOUX FALLS HAS ISSUED A * URBAN FLOOD WARNING FOR... BUENA VISTA COUNTY IN NORTHWESTERN IOWA CHEROKEE COUNTY IN NORTHWESTERN IOWA IDA COUNTY IN NORTHWESTERN IOWA WOODBURY COUNTY IN NORTHWESTERN IOWA DAKOTA COUNTY IN NORTHEASTERN NEBRASKA * UNTIL 620 AM CDT * AT 315 AM CDT... NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED VERY HEAVY RAIN AROUND SIOUX CITY...MOVING SLOWLY NORTHEAST. RAINFALL AMOUNTS WILL RANGE FROM AN INCH TO TWO INCHES IN A HOUR.p..SO LOCALIZED URBAN FLOODING IS LIKELY. DAKOTA COUNTY EMERGENCY MANAGEMENT REPORTED SOME HOMES IN SOUTH SIOUX CITY WERE FLOODED. MANY OF THESE HOMES WERE HIT HARD A WEEK AGO. DON'T DRIVE INTO AREAS WHERE WATER COVERS THE ROAD. HEITKAMP
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.
NWS Sioux Falls, SD wrote its last area forecast discussion before this flash flood warning went out at Jul 17, 9:15 PM CDT, 6 hours 6 minutes earlier.
Area forecast discussion, Jul 17, 9:15 PM CDT, 6 hours 6 minutes before
AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA NATIONAL WEATHER SERVICE SIOUX FALLS SD 915 PM CDT SAT JUL 17 1999 SO FAR ONLY A FEW LGT SHWRS MOVG OVER AREA. PROSPECTS FOR MORE SIGNFCNT RAIN HINGE ON DVLPMNT TO SW AND INTRACTN WITH WRMFNT SRN EDGE OF AREA. PRBLM IS THIS IS STILL PSBL WITH VERY RIPE AIR S OF WRMFNT. WILL UPDATE ZNS A LTL LATR...BY 04Z...TO REFINE AT LEAST WORDG AND PRBLY OTHR PARAMETERS AS WELL. WILL CHECK OUT SIGNS OF DVLPMNT NEXT HR OR SO AND MAYBE CHECK OUT NEW GUIDNCE AS IT COMES IN. 00Z RUC INDICATES POTENTL. FOR NEXT CPL OF HRS CURNT ZNS OK GIVEN UNCERTAINTIES IN PCPN DVLPMNT. .FSD...NONE WILLIAMS
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; radar from the NEXRAD Level II archive.