Alert archive / Iowa / Flash Flood Warnings in 2016
Flash Flood Warning 1, NWS Sioux Falls, SD
NWS Sioux Falls, SD issued this flash flood warning at May 9, 2016, 8:51 PM CDT for Cherokee County, Iowa. It was in force for 5 hr. 2 reports came from inside the area while it was in force.
The area
The outline as issued, with what was reported inside it.
The facts
- Issued
- May 9, 2016, 8:51 PM CDT (01:51 UTC)
- Expired
- May 10, 2016, 1:45 AM CDT
- In force
- 5 hr
- Issued by
- NWS Sioux Falls, SD
- Area
- Storm-based polygon
- Flood severity
- None
County Cherokee County, IA
The radar
The Sioux Falls radar (KFSD), 132 km from the middle of the area, began a volume at 01:54 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.
What was reported inside it
| Time | Report | Where | Remark |
|---|---|---|---|
| May 9, 9:00 PM CDT | FLASH FLOOD | 6 Nnw Washta, IA | A 30 FOOT SECTION OF F AVENUE WASHED OUT BETWEEN 590TH AND 600TH STREETS. |
| May 9, 9:30 PM CDT | FLASH FLOOD | 4 Wnw Washta, IA | COUNTY ROAD 630TH WASHED OUT BETWEEN D AND E AVENUES DUE TO FLASH FLOODING. |
Local storm reports filed while the alert was in force, from inside its polygon or its counties.
The nearest sounding before it
Omaha, NE (KOAX), launched 00:00Z, 1.9 hours before the alert went out and 154 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
- 37 J/kg
- Mixed-layer CIN
- -85 J/kg
- Mixed-layer LCL
- 2626 m above ground
- 0-6 km bulk shear
- 26 kt
- 0-1 km storm-relative helicity
- 51 m²/s²
- 0-3 km storm-relative helicity
- 202 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- -0.4
The text
As transmitted.
488 WGUS53 KFSD 100151 FFWFSD IAC035-100645- /O.NEW.KFSD.FF.W.0001.160510T0151Z-160510T0645Z/ /00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/ BULLETIN - EAS ACTIVATION REQUESTED FLASH FLOOD WARNING NATIONAL WEATHER SERVICE SIOUX FALLS SD 851 PM CDT MON MAY 9 2016 THE NATIONAL WEATHER SERVICE IN SIOUX FALLS HAS ISSUED A * FLASH FLOOD WARNING FOR... SOUTHWESTERN CHEROKEE COUNTY IN NORTHWESTERN IOWA... * UNTIL 145 AM CDT * AT 847 PM CDT...DOPPLER RADAR INDICATED THUNDERSTORMS PRODUCING HEAVY RAIN ACROSS THE WARNED AREA. UP TO THREE INCHES OF RAIN HAVE ALREADY FALLEN. * SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE... WASHTA. OVERALL RADAR TRENDS ARE SHOWING A DECREASE IN INTENSITY AND COVERAGE OF INDIVIDUAL STORMS IN NORTHWEST IOWA. HOWEVER ADDITIONAL CELLS CONTINUE TO REFORM OVER A SECTION OF SOUTHWEST CHEROKEE COUNTY. DUE TO PERIODIC RAIN DEVELOPMENT...FLASH FLOODING IS A SERIOUS CONCERN OVER RURAL ROADS, DITCHES AND SMALL STREAMS OVER THE NEXT SEVERAL HOURS. PRECAUTIONARY/PREPAREDNESS ACTIONS... BE ESPECIALLY CAUTIOUS AT NIGHT WHEN IT IS HARDER TO RECOGNIZE THE DANGERS OF FLOODING. && LAT...LON 4256 9583 4273 9582 4273 9567 4256 9567 $$ MJF
2 follow-up statements
840 WGUS73 KFSD 100351 FFSFSD FLASH FLOOD STATEMENT NATIONAL WEATHER SERVICE SIOUX FALLS SD 1051 PM CDT MON MAY 9 2016 IAC035-100645- /O.CON.KFSD.FF.W.0001.000000T0000Z-160510T0645Z/ /00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/ CHEROKEE IA- 1051 PM CDT MON MAY 9 2016 ...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 145 AM CDT FOR SOUTHWESTERN CHEROKEE COUNTY... AT 1046 PM CDT...DOPPLER RADAR INDICATED THAT THE THUNDERSTORMS PRODUCING THE HEAVY RAINFALL EARLIER THIS EVENING HAD EITHER DISSIPATED OR MOVED OUT OF THE AREA. ADDITIONAL RAINFALL AMOUNTS ARE POSSIBLE UNTIL SHORTLY AFTER MIDNIGHT. HOWEVER THE ADDITIONAL RAINFALL LOOKS FAIRLY LIGHT AND SHOULD NOT ADD TO THE ALREADY EXISTING FLOODING THREAT. IT HAS BEEN REPORTED THAT A COUPLE OF COUNTY ROADS IN SOUTHWEST CHEROKEE COUNTY WERE WASHED OUT AND HAVE BEEN BARRICADED. IT IS QUITE POSSIBLE THAT THIS FLASH FLOOD WARNING WILL NOT HAVE TO BE EXTENDED...BUT WILL CONTINUE UNTIL 145 AM TO ALLOW FOR THE CURRENT WATER TO RECEDE. SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE... WASHTA. PRECAUTIONARY/PREPAREDNESS ACTIONS... BE ESPECIALLY CAUTIOUS AT NIGHT WHEN IT IS HARDER TO RECOGNIZE THE DANGERS OF FLOODING. DO NOT DRIVE AROUND BARRICADES. && LAT...LON 4256 9583 4273 9582 4273 9567 4256 9567 $$ MJF
850 WGUS73 KFSD 100642 FFSFSD FLASH FLOOD STATEMENT NATIONAL WEATHER SERVICE SIOUX FALLS SD 142 AM CDT TUE MAY 10 2016 IAC035-100651- /O.EXP.KFSD.FF.W.0001.000000T0000Z-160510T0645Z/ /00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/ CHEROKEE IA- 142 AM CDT TUE MAY 10 2016 ...THE FLASH FLOOD WARNING FOR SOUTHWESTERN CHEROKEE COUNTY WILL EXPIRE AT 145 AM CDT... THE HEAVY RAIN HAS ENDED...HOWEVER LIGHT RAIN WILL CONTINUE FOR THE NEXT HOUR. FLOODING IS NO LONGER EXPECTED TO POSE A THREAT. PLEASE CONTINUE TO HEED ANY REMAINING ROAD CLOSURES. LAT...LON 4256 9583 4273 9582 4273 9567 4256 9567 $$ HANKO
The office that day
Everything else NWS Sioux Falls, SD issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 9, 9:11 PM CDT | River Flood Warning | FSD | Cherokee | 4 days |
| May 10, 7:36 AM CDT | River Flood Warning | FSD | Clay, Dickinson | 6 days |
| May 10, 7:36 AM CDT | River Flood Warning | FSD | Clay, Dickinson | 3 days |
| May 10, 2:16 PM CDT | River Flood Warning | FSD | Clay | 3 days |
| May 10, 2:16 PM CDT | River Flood Warning | FSD | Woodbury | 36 hr |
Nearby
Flash Flood Warnings in Iowa, 2016Every flash flood warning in 2016
Sources
The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.