Alert archive / Iowa / Flash Flood Warnings in 2016

Flash Flood Warning 25, NWS La Crosse, WI

August 24, 20164 counties in Iowa

NWS La Crosse, WI issued this flash flood warning at Aug 24, 2016, 6:46 AM CDT for 4 counties in Iowa. It was in force for 6 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
Aug 24, 2016, 6:46 AM CDT (11:46 UTC)
Expired
Aug 24, 2016, 12:45 PM CDT
In force
6 hr
Issued by
NWS La Crosse, WI
Area
Storm-based polygon
Emergency
Flash flood emergency
Flood severity
None

Counties Allamakee County, IA, Chickasaw County, IA, Howard County, IA, Winneshiek County, IA

The radar

The La Crosse radar (KARX), 68 km from the middle of the area, began a volume at 11:46 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

TimeReportWhereRemark
Aug 24, 8:17 AM CDTHEAVY RAIN 72 E Waukon, IA.
Aug 24, 8:24 AM CDTFLOOD6 Ese Decorah, IABRIDGE ON 225TH NEAR OIL WELL ROAD OVERTAKEN BY WATER.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Davenport, (KDVN), launched 00:00Z, 11.8 hours before the alert went out and 204 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, Davenport, at 00:00Z on 2016-08-24Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 83 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Davenport, at 00:00Z on 2016-08-24The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 115 square meters per square second.193958Sfc1 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
83 J/kg
Mixed-layer CIN
-226 J/kg
Mixed-layer LCL
974 m above ground
0-6 km bulk shear
16 kt
0-1 km storm-relative helicity
115 m²/s²
0-3 km storm-relative helicity
201 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

675 
WGUS53 KARX 241146
FFWARX
IAC005-037-089-191-241745-
/O.NEW.KARX.FF.W.0025.160824T1146Z-160824T1745Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE LA CROSSE WI
646 AM CDT WED AUG 24 2016

...FLASH FLOOD EMERGENCY...

THE NATIONAL WEATHER SERVICE IN LA CROSSE HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  NORTHEASTERN CHICKASAW COUNTY IN NORTHEASTERN IOWA...
  SOUTHEASTERN HOWARD COUNTY IN NORTHEASTERN IOWA...
  ALLAMAKEE COUNTY IN NORTHEASTERN IOWA...
  WINNESHIEK COUNTY IN NORTHEASTERN IOWA...

* UNTIL 1245 PM CDT WEDNESDAY

* AT 645 AM CDT...LOCAL LAW ENFORCEMENT OFFICIALS REPORTED FLASH
  FLOODING WITH WATER RESCUES ONGOING ACROSS THE WARNED AREA. 

  THIS IS A FLASH FLOOD EMERGENCY. THIS IS A PARTICULARLY DANGEROUS
  SITUATION. SEEK HIGHER GROUND NOW! STAY AWAY FROM FLOOD WATERS!  

* SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE...
  DECORAH...WAUKON...CRESCO...LANSING...POSTVILLE...CALMAR...
  OSSIAN...ELMA...NEW ALBIN...LAWLER...SPILLVILLE...FORT ATKINSON...
  HARPERS FERRY...RIDGEWAY...PROTIVIN...JERICO...HARDIN...
  ALTA VISTA...CASTALIA AND WATERVILLE.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

MOVE TO HIGHER GROUND NOW. THIS IS AN EXTREMELY DANGEROUS AND
LIFE-THREATENING SITUATION. DO NOT ATTEMPT TO TRAVEL UNLESS YOU ARE
FLEEING AN AREA SUBJECT TO FLOODING OR UNDER AN EVACUATION ORDER.

TURN AROUND...DON'T DROWN WHEN ENCOUNTERING FLOODED ROADS. MOST FLOOD
DEATHS OCCUR IN VEHICLES.

&&

LAT...LON 4350 9215 4350 9122 4345 9123 4341 9120
      4335 9121 4332 9111 4325 9106 4320 9112
      4315 9115 4313 9118 4308 9118 4308 9208
      4306 9208 4309 9244 4332 9246

$$

WETENKAMP
2 follow-up statements
135 
WGUS73 KARX 241351
FFSARX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE LA CROSSE WI
851 AM CDT WED AUG 24 2016

IAC005-037-089-191-241745-
/O.CON.KARX.FF.W.0025.000000T0000Z-160824T1745Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
CHICKASAW IA-HOWARD IA-ALLAMAKEE IA-WINNESHIEK IA-
851 AM CDT WED AUG 24 2016

...THIS IS A FLASH FLOOD EMERGENCY...

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 1245 PM CDT FOR
NORTHEASTERN CHICKASAW...SOUTHEASTERN HOWARD...ALLAMAKEE AND
WINNESHIEK COUNTIES...

AT 835 AM CDT...LOCAL LAW ENFORCEMENT REPORTS MAJOR FLOODING ACROSS
THE AREA. THIS IS A POTENTIALLY HISTORIC EVENT. FLOODING OF THIS
MAGNITUDE MAY NOT HAVE BEEN SEEN BY MANY ACROSS THESE AREAS.

THIS IS A FLASH FLOOD EMERGENCY...ESPECIALLY FOR FREEPORT...
SPILLVILLE...AND DECORAH. THIS IS A PARTICULARLY DANGEROUS
SITUATION. SEEK HIGHER GROUND NOW! 

THE MOST IMPACTED AREAS INCLUDE
FREEPORT...SPILLVILLE...DECORAH...AND FORT ATKINSON. EVACUATIONS ARE
UNDERWAY AT FREEPORT. MAJOR IMPACTS ONGOING ALONG MANY AREA RIVERS
AND STREAMS. MULTIPLE ROADS HAVE BEEN WASHED OUT. DUE TO THE
WIDESPREAD DAMAGING FLOODING AND STRAINED RESOURCES IT IS POSSIBLE
THAT NOT ALL WASHED OUT ROADS ARE BARRICADED. 

AN EMERGENCY SHELTER HAS BEEN OPENED AT STONE RIDGE COMMUNITY CHURCH
LOCATED AT THE INTERSECTION OF MONTGOMERY STREET AND HIGHWAY 9 IN
DECORAH. 

EXCESSIVE RAINFALL OVER THE WARNED AREA WILL CAUSE MUD SLIDES NEAR
STEEP TERRAIN. THE MUD SLIDE CAN CONSIST OF ROCK...MUD...VEGETATION
AND OTHER LOOSE MATERIALS.

SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE...
DECORAH...WAUKON...CRESCO...LANSING...POSTVILLE...CALMAR...OSSIAN...
ELMA...NEW ALBIN...LAWLER...SPILLVILLE...FORT ATKINSON...
HARPERS FERRY...RIDGEWAY...PROTIVIN...JERICO...HARDIN...ALTA VISTA...
CASTALIA AND WATERVILLE.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

MOVE TO HIGHER GROUND NOW. THIS IS AN EXTREMELY DANGEROUS AND
LIFE-THREATENING SITUATION. DO NOT ATTEMPT TO TRAVEL UNLESS YOU ARE
FLEEING AN AREA SUBJECT TO FLOODING OR UNDER AN EVACUATION ORDER.

TURN AROUND...DON'T DROWN WHEN ENCOUNTERING FLOODED ROADS. MOST FLOOD
DEATHS OCCUR IN VEHICLES.

&&

LAT...LON 4350 9215 4350 9122 4345 9123 4341 9120
      4335 9121 4332 9111 4325 9106 4320 9112
      4315 9115 4313 9118 4308 9118 4308 9208
      4306 9208 4309 9244 4332 9246

$$

WETENKAMP
347 
WGUS73 KARX 241558
FFSARX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE LA CROSSE WI
1058 AM CDT WED AUG 24 2016

IAC005-037-089-191-241557-
/O.CAN.KARX.FF.W.0025.000000T0000Z-160824T1745Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
CHICKASAW IA-HOWARD IA-ALLAMAKEE IA-WINNESHIEK IA-
1058 AM CDT WED AUG 24 2016

...THE FLASH FLOOD WARNING FOR NORTHEASTERN CHICKASAW...SOUTHEASTERN
HOWARD...ALLAMAKEE AND WINNESHIEK COUNTIES IS CANCELLED...

WIDESPREAD FLOODING CONTINUES IN THE AFFECTED AREA FROM OVERNIGHT
HEAVY RAINFALL. LAW ENFORCEMENT REPORTS THAT THE SITUATION HAS
STABILIZED OVER THE PAST HOURS WITH NO RECENT EVACUATIONS AND
RESCUES. 

THEREFORE...THE FLASH FLOOD EMERGENCY WILL BE REPLACED BY A FLOOD
WARNING. 

LAW ENFORCEMENT REPORTS MANY ROADS ARE FLOODED OR WASHED OUT FROM
THE HEAVY RAINFALL. IN ISOLATED AREAS...SUCH AS ALONG STATE
HIGHWAYS...THE WATER LEVELS ARE NO LONGER OVER THE ROAD. 

MANY SECONDARY ROADS ARE DAMAGED OR CLOSED. ALSO...MANY CREEKS AND
RIVERS ARE FLOODING...SOME AT MAJOR FLOOD LEVELS. THIS INCLUDES THE
UPPER IOWA RIVER AND TURKEY RIVER. TRAVEL IS STILL NOT RECOMMENDED.
THEREFORE...THE FLOOD WARNING WILL BE IN EFFECT UNTIL 11 AM
THURSDAY.  

PLEASE CONTINUE TO HEED ANY REMAINING ROAD CLOSURES. DRIVING THROUGH
FLOOD WATERS IS DANGEROUS...MOST LIVES ARE LOST IN FLOODING BECAUSE
PEOPLE DRIVE INTO WATER AND ARE SWEPT AWAY. 

LAT...LON 4350 9215 4350 9122 4345 9123 4341 9120
      4335 9121 4332 9111 4325 9106 4320 9112
      4315 9115 4313 9118 4308 9118 4308 9208
      4306 9208 4309 9244 4332 9246

$$

BAUMGARDT

The office that day

Everything else NWS La Crosse, WI issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Aug 23, 8:30 PM CDTSpecial Weather StatementARXChickasaw, Winneshiek60 min
Aug 23, 9:10 PM CDTAreal Flood AdvisoryARXAllamakee, Chickasaw, Clayton, Fayette, Floyd, Howard and 2 more3 hr
Aug 23, 9:57 PM CDTAreal Flood WarningARXChickasaw, Floyd, Howard9 hr
Aug 23, 10:11 PM CDTFlash Flood WarningARXWinneshiek4 hr
Aug 24, 12:21 AM CDTFlash Flood WarningARXHoward, Mitchell4 hr
Aug 24, 1:02 AM CDTFlash Flood WarningARXAllamakee, Winneshiek6 hr
Aug 24, 2:05 AM CDTRiver Flood WarningARXWinneshiek25 hr
Aug 24, 2:05 AM CDTRiver Flood WarningARXAllamakee3 days
Aug 24, 3:36 AM CDTAreal Flood WarningARXFayette32 hr
Aug 24, 3:48 AM CDTFlash Flood WarningARXChickasaw, Howard3 hr
Aug 24, 4:11 AM CDTRiver Flood WarningARXWinneshiek17 hr
Aug 24, 4:17 AM CDTAreal Flood WarningARXHoward, Mitchell3 hr
Aug 24, 8:00 AM CDTRiver Flood WarningARXFloyd48 hr
Aug 24, 8:59 AM CDTRiver Flood WarningARXClayton4 days
Aug 24, 8:59 AM CDTRiver Flood WarningARXClayton3 days
Aug 24, 10:38 AM CDTSpecial Weather StatementARXChickasaw, Winneshiek82 min
Aug 24, 11:03 AM CDTAreal Flood WarningARXAllamakee, Chickasaw, Howard, Winneshiek24 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.