Alert archive / Iowa / Flash Flood Warnings in 2012
Flash Flood Warning 4, NWS La Crosse, WI
NWS La Crosse, WI issued this flash flood warning at Sep 4, 2012, 11:09 PM CDT for Allamakee County, Winneshiek County, Iowa. It was in force for 5 hr. No storm report in the archive falls inside the area while it was in force.
The area
The outline as issued.
The facts
- Issued
- Sep 4, 2012, 11:09 PM CDT (04:09 UTC)
- Expired
- Sep 5, 2012, 4:00 AM CDT
- In force
- 5 hr
- Issued by
- NWS La Crosse, WI
- Area
- Storm-based polygon
- Flood severity
- None
Counties Allamakee County, IA, Winneshiek County, IA
The radar
The La Crosse radar (KARX), 81 km from the middle of the area, began a volume at 04:12 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
Davenport, (KDVN), launched 00:00Z, 4.2 hours before the alert went out and 194 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
- 1890 J/kg
- Mixed-layer CIN
- -49 J/kg
- Mixed-layer LCL
- 1662 m above ground
- 0-6 km bulk shear
- 32 kt
- 0-1 km storm-relative helicity
- -23 m²/s²
- 0-3 km storm-relative helicity
- 44 m²/s²
- Significant tornado parameter
- -0.0
- Supercell composite
- -0.9
The text
As transmitted, in the capitals the NWS used until 2016.
689 WGUS53 KARX 050409 FFWARX IAC005-191-050900- /O.NEW.KARX.FF.W.0004.120905T0409Z-120905T0900Z/ /00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/ BULLETIN - EAS ACTIVATION REQUESTED FLASH FLOOD WARNING NATIONAL WEATHER SERVICE LA CROSSE WI 1109 PM CDT TUE SEP 4 2012 THE NATIONAL WEATHER SERVICE IN LA CROSSE HAS ISSUED A * FLASH FLOOD WARNING FOR... SOUTHEASTERN WINNESHIEK COUNTY IN NORTHEAST IOWA... SOUTHERN ALLAMAKEE COUNTY IN NORTHEAST IOWA... * UNTIL 400 AM CDT * AT 1108 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED SLOW MOVING THUNDERSTORMS WITH VERY HEAVY RAINFALL ACROSS THE WARNED AREA. RADAR ESTIMATES THAT 2 TO 3 INCHES OF RAIN HAS FALLEN WITH AN ADDITIONAL INCH POSSIBLE THROUGH MIDNIGHT. * RUNOFF FROM THIS EXCESSIVE RAINFALL WILL CAUSE FLASH FLOODING TO OCCUR. SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE... OSSIAN AND POSTVILLE. PRECAUTIONARY/PREPAREDNESS ACTIONS... EXCESSIVE RUNOFF FROM HEAVY RAINFALL WILL CAUSE FLOODING OF SMALL CREEKS AND STREAMS...COUNTRY ROADS...AS WELL AS FARMLAND ALONG THE BANKS OF CREEKS AND STREAMS. BE ESPECIALLY CAUTIOUS AT NIGHT WHEN IT IS HARDER TO RECOGNIZE THE DANGERS OF FLOODING. IF FLASH FLOODING IS OBSERVED ACT QUICKLY. DO NOT ENTER THE WATER. TURN AROUND AND MOVE UP TO HIGHER GROUND TO ESCAPE FLOOD WATERS. DO NOT STAY IN AREAS SUBJECT TO FLOODING WHEN WATER BEGINS RISING. && LAT...LON 4322 9183 4321 9125 4308 9127 4308 9182 $$ JW
3 follow-up statements
520 WGUS73 KARX 050443 FFSARX FLASH FLOOD STATEMENT NATIONAL WEATHER SERVICE LA CROSSE WI 1143 PM CDT TUE SEP 4 2012 IAC005-191-050900- /O.CON.KARX.FF.W.0004.000000T0000Z-120905T0900Z/ /00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/ ALLAMAKEE IA-WINNESHIEK IA- 1143 PM CDT TUE SEP 4 2012 ...FLASH FLOOD WARNING REMAINS IN EFFECT FOR SOUTHEASTERN WINNESHIEK AND SOUTHERN ALLAMAKEE COUNTIES UNTIL 400 AM CDT... AT 1140 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED THUNDERSTORMS WITH VERY HEAVY RAINFALL ACROSS THE WARNED AREA. RADAR ESTIMATES THAT 3 TO 4 INCHES OF RAIN HAS FALLEN IN THE WARNED AREA...WITH AN ADDITIONAL 2 TO 3 INCHES POSSIBLE. RUNOFF FROM THIS EXCESSIVE RAINFALL WILL CAUSE FLASH FLOODING TO OCCUR. SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE...OSSIAN AND POSTVILLE. PRECAUTIONARY/PREPAREDNESS ACTIONS... EXCESSIVE RUNOFF FROM THIS STORM WILL CAUSE FLOODING OF SMALL CREEKS AND STREAMS...COUNTRY ROADS...NORMALLY DRY WASHES... AS WELL AS FARMLAND ALONG THE BANKS OF CREEKS AND STREAMS. BE ESPECIALLY CAUTIOUS AT NIGHT WHEN IT IS HARDER TO RECOGNIZE THE DANGERS OF FLOODING. IF FLOODING IS OBSERVED...ACT QUICKLY. DO NOT ENTER THE WATER. TURN AROUND AND MOVE UP TO HIGHER GROUND. DO NOT STAY IN AREAS SUBJECT TO FLOODING WHEN WATER BEGINS RISING. && LAT...LON 4322 9183 4321 9125 4308 9127 4308 9182 $$ JW
126 WGUS73 KARX 050706 FFSARX FLASH FLOOD STATEMENT NATIONAL WEATHER SERVICE LA CROSSE WI 206 AM CDT WED SEP 5 2012 IAC005-191-050900- /O.CON.KARX.FF.W.0004.000000T0000Z-120905T0900Z/ /00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/ ALLAMAKEE IA-WINNESHIEK IA- 206 AM CDT WED SEP 5 2012 ...FLASH FLOOD WARNING REMAINS IN EFFECT FOR SOUTHEASTERN WINNESHIEK AND SOUTHERN ALLAMAKEE COUNTIES UNTIL 400 AM CDT... AT 204 AM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED THUNDERSTORMS WITH VERY HEAVY RAINFALL ACROSS THE WARNED AREA. RADAR ESTIMATED 4 TO 5 INCHES OF RAIN HAS ALREADY FALLEN...WITH ANOTHER INCH POSSIBLE. RUNOFF FROM THIS EXCESSIVE RAINFALL WILL CAUSE FLASH FLOODING TO OCCUR. SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE...OSSIAN AND POSTVILLE. PRECAUTIONARY/PREPAREDNESS ACTIONS... EXCESSIVE RUNOFF FROM THIS STORM WILL CAUSE FLOODING OF SMALL CREEKS AND STREAMS...COUNTRY ROADS...NORMALLY DRY WASHES... AS WELL AS FARMLAND ALONG THE BANKS OF CREEKS AND STREAMS. BE ESPECIALLY CAUTIOUS AT NIGHT WHEN IT IS HARDER TO RECOGNIZE THE DANGERS OF FLOODING. IF FLOODING IS OBSERVED...ACT QUICKLY. DO NOT ENTER THE WATER. TURN AROUND AND MOVE UP TO HIGHER GROUND. DO NOT STAY IN AREAS SUBJECT TO FLOODING WHEN WATER BEGINS RISING. && LAT...LON 4322 9183 4321 9125 4308 9127 4308 9182 $$
260 WGUS73 KARX 050855 FFSARX FLASH FLOOD STATEMENT NATIONAL WEATHER SERVICE LA CROSSE WI 355 AM CDT WED SEP 5 2012 IAC005-191-050909- /O.EXP.KARX.FF.W.0004.000000T0000Z-120905T0900Z/ /00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/ ALLAMAKEE IA-WINNESHIEK IA- 355 AM CDT WED SEP 5 2012 ...THE FLASH FLOOD WARNING THAT WAS IN EFFECT FOR SOUTHEASTERN WINNESHIEK AND SOUTHERN ALLAMAKEE COUNTIES WILL BE ALLOWED TO EXPIRE AT 400 AM CDT... SHERIFF DEPARTMENTS FROM WINNESHIEK AND ALLAMAKEE COUNTIES HAVE SAID THAT NO FLOODING HAS BEEN REPORTED AND ANY EXCESS RUNOFF FROM HEAVY RAIN HAS ENDED OVER THE WARNED AREA. STREAMS AND CREEKS IN THE WARNED AREA HAVE RECEDED OR WERE BEGINNING TO RECEDE...ENDING THE FLOOD THREAT. IF FLOODING HAS BEEN OBSERVED...PLEASE REPORT IT TO YOUR LOCAL LAW ENFORCEMENT AGENCY. LAT...LON 4322 9183 4321 9125 4308 9127 4308 9182 $$ HALBACH
The office that day
Everything else NWS La Crosse, WI issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Sep 4, 7:06 PM CDT | Severe Thunderstorm Warning | ARX | Allamakee | 24 min |
| Sep 4, 7:35 PM CDT | Severe Thunderstorm Warning | ARX | Clayton | 70 min |
| Sep 4, 8:09 PM CDT | Flash Flood Warning | ARX | Allamakee, Clayton | 6 hr |
| Sep 4, 10:10 PM CDT | Severe Thunderstorm Warning | ARX | Clayton, Fayette | 65 min |
| Sep 4, 10:42 PM CDT | Severe Thunderstorm Warning | ARX | Allamakee, Winneshiek | 33 min |
| Sep 4, 11:14 PM CDT | Severe Thunderstorm Warning | ARX | Clayton | 46 min |
| Sep 4, 11:36 PM CDT | Severe Thunderstorm Warning | ARX | Allamakee, Clayton, Fayette, Winneshiek | 47 min |
| Sep 4, 11:59 PM CDT | Severe Thunderstorm Warning | ARX | Clayton | 61 min |
| Sep 5, 12:12 AM CDT | Severe Thunderstorm Warning | ARX | Floyd, Mitchell | 63 min |
| Sep 5, 12:31 AM CDT | Severe Thunderstorm Warning | ARX | Chickasaw, Howard | 44 min |
| Sep 5, 1:06 AM CDT | Severe Thunderstorm Warning | ARX | Fayette, Winneshiek | 24 min |
| Sep 5, 1:28 AM CDT | Severe Thunderstorm Warning | ARX | Allamakee | 32 min |
| Sep 5, 1:51 AM CDT | Flash Flood Warning | ARX | Clayton, Fayette | 3 hr |
| Sep 5, 1:59 AM CDT | Flash Flood Warning | ARX | Allamakee, Clayton | 3 hr |
Nearby
Flash Flood Warnings in Iowa, 2012Every flash flood warning in 2012
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.