Alert archive / Iowa / Flash Flood Warnings in 2011

Flash Flood Warning 17, NWS La Crosse, WI

July 28, 2011Clayton County, Iowa

NWS La Crosse, WI issued this flash flood warning at Jul 28, 2011, 2:36 AM CDT for Clayton County, Iowa. It was in force for 5 hr. 6 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: Jul 28, 2011, 2:36 AM CDT (07:36 UTC)
Expired: Jul 28, 2011, 7:30 AM CDT
In force: 5 hr
Issued by: NWS La Crosse, WI
Area: Storm-based polygon
Flood severity: None

County Clayton County, IA

The radar

The La Crosse radar (KARX), 119 km from the middle of the area, began a volume at 07:39 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
Jul 28, 4:35 AM CDT	FLASH FLOOD	Osterdock, IA	WATER CAME OVER SEVERAL NEARBY ROADS CAUSING DAMAGE.
Jul 28, 5:25 AM CDT	FLASH FLOOD	Millville, IA	THE LITTLE TURKEY RIVER WAS OUT OF ITS BANKS AND OVER GRAHAM ROAD. WATER RISING INTO HOMES NEAR THE INTERSECTION OF HIGHWAY 52 AND GRAHAM ROAD.
Jul 28, 5:47 AM CDT	HEAVY RAIN 3.07	Edgewood, IA
Jul 28, 7:00 AM CDT	HEAVY RAIN 3.44	Guttenberg, IA
Jul 28, 7:00 AM CDT	HEAVY RAIN 4.84	Littleport, IA
Jul 28, 7:00 AM CDT	HEAVY RAIN 4.99	Volga, IA

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, 7.6 hours before the alert went out and 140 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 4556 J/kg
Mixed-layer CIN: -8 J/kg
Mixed-layer LCL: 962 m above ground
0-6 km bulk shear: 32 kt
0-1 km storm-relative helicity: 141 m²/s²
0-3 km storm-relative helicity: 316 m²/s²
Significant tornado parameter: 3.9
Supercell composite: 19.4

Open this sounding in Storm Lab

The text

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

312 
WGUS53 KARX 280736
FFWARX
IAC043-281230-
/O.NEW.KARX.FF.W.0017.110728T0736Z-110728T1230Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE LA CROSSE WI
236 AM CDT THU JUL 28 2011

THE NATIONAL WEATHER SERVICE IN LA CROSSE HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  SOUTHERN CLAYTON COUNTY IN NORTHEAST IOWA...

* UNTIL 730 AM CDT

* AT 235 AM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED   
  SLOW MOVING THUNDERSTORMS WITH VERY HEAVY RAINFALL ACROSS THE      
  WARNED AREA...RAINFALL RATES OF 1 TO 3 INCHES PER HOUR. 

* RUNOFF FROM THIS EXCESSIVE RAINFALL WILL CAUSE FLASH FLOODING TO
  OCCUR. SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE...
  ELKADER...GUTTENBERG...EDGEWOOD...GARNAVILLO...STRAWBERRY POINT AND
  VOLGA. 

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 4265 9161 4292 9161 4293 9161 4288 9112
      4286 9109 4274 9105 4268 9095 4268 9090
      4265 9089 4264 9108

$$

RABERDING

4 follow-up statements

138 
WGUS73 KARX 280844
FFSARX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE LA CROSSE WI
344 AM CDT THU JUL 28 2011

IAC043-281230-
/O.CON.KARX.FF.W.0017.000000T0000Z-110728T1230Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
CLAYTON IA-
344 AM CDT THU JUL 28 2011

...FLASH FLOOD WARNING REMAINS IN EFFECT FOR SOUTHERN CLAYTON COUNTY
UNTIL 730 AM CDT...

AT 344 AM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED 
THUNDERSTORMS WITH VERY HEAVY RAINFALL ACROSS THE WARNED AREA. RADAR 
ESTIMATES OF 3 TO 5 INCHES HAVE FALLEN...WITH THE HIGHER AMOUNTS 
ACROSS SOUTHEASTERN CLAYTON COUNTY.

RUNOFF FROM THIS EXCESSIVE RAINFALL WILL CAUSE FLASH FLOODING TO
OCCUR. SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE...
ELKADER...GUTTENBERG...EDGEWOOD...GARNAVILLO...STRAWBERRY POINT AND
VOLGA.

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 4265 9161 4292 9161 4293 9161 4288 9112
      4286 9109 4274 9105 4268 9095 4268 9090
      4265 9089 4264 9108

$$

RABERDING

058 
WGUS73 KARX 280958
FFSARX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE LA CROSSE WI
458 AM CDT THU JUL 28 2011

IAC043-281230-
/O.CON.KARX.FF.W.0017.000000T0000Z-110728T1230Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
CLAYTON IA-
458 AM CDT THU JUL 28 2011

...FLASH FLOOD WARNING REMAINS IN EFFECT FOR SOUTHERN CLAYTON COUNTY
UNTIL 730 AM CDT...

AT 457 AM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED 
THUNDERSTORMS WITH VERY HEAVY RAINFALL ACROSS THE WARNED AREA. RADAR 
ESTIMATES OF 3 TO 6 INCHES OF RAIN HAVE FALLEN ACROSS THE WARNED AREA 
OVERNIGHT.

RUNOFF FROM THIS EXCESSIVE RAINFALL WILL CAUSE FLASH FLOODING TO
OCCUR. SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE...
ELKADER...GUTTENBERG...EDGEWOOD...GARNAVILLO...STRAWBERRY POINT AND
VOLGA.

LAW ENFORCEMENT REPORTED THAT MANY STREAMS AND DITCHES WERE 
BEGINNING TO OVERFLOW ACROSS THE SOUTHERN PART OF THE COUNTY.

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 4265 9161 4292 9161 4293 9161 4288 9112
      4286 9109 4274 9105 4268 9095 4268 9090
      4265 9089 4264 9108

$$

RABERDING

258 
WGUS73 KARX 281039
FFSARX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE LA CROSSE WI
539 AM CDT THU JUL 28 2011

IAC043-281230-
/O.CON.KARX.FF.W.0017.000000T0000Z-110728T1230Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
CLAYTON IA-
539 AM CDT THU JUL 28 2011

...FLASH FLOOD WARNING REMAINS IN EFFECT FOR SOUTHERN CLAYTON COUNTY
UNTIL 730 AM CDT...

AT 532 AM CDT...LOCAL LAW ENFORCEMENT OFFICIALS REPORTED FLASH 
FLOODING ACROSS THE WARNED AREA. DOPPLER RADAR ESTIMATES 
THUNDERSTORMS HAVE PRODUCED 4 TO 7 INCHES OF RAINFALL EARLY THIS 
MORNING...WITH ANOTHER 2 INCHES OF RAIN POSSIBLE THROUGH 730 AM.  

RUNOFF FROM THIS EXCESSIVE RAINFALL WILL CAUSE FLASH FLOODING TO 
OCCUR. SOME LOCATIONS THAT WILL EXPERIENCE FLOODING 
INCLUDE...ELKADER...MILLVILLE...GUTTENBERG...EDGEWOOD...GARNAVILLO 
STRAWBERRY POINT AND VOLGA.

LAW ENFORCEMENT REPORTS THAT THE LITTLE TURKEY RIVER IS OUT OF ITS 
BANKS NEAR MILLVILLE. GRAHAM ROAD WAS UNDER WATER...WITH THE WATER 
RISING INTO HOMES NEAR THE INTERSECTION OF HIGHWAY 52 AND GRAHAM 
ROAD. 

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.

&&

LAT...LON 4265 9161 4292 9161 4293 9161 4288 9112
      4286 9109 4274 9105 4268 9095 4268 9090
      4265 9089 4264 9108

$$

JW

341 
WGUS73 KARX 281222
FFSARX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE LA CROSSE WI
722 AM CDT THU JUL 28 2011

IAC043-281230-
/O.CON.KARX.FF.W.0017.000000T0000Z-110728T1230Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
CLAYTON IA-
722 AM CDT THU JUL 28 2011

...FLASH FLOOD WARNING REMAINS IN EFFECT FOR SOUTHERN CLAYTON COUNTY
UNTIL 730 AM CDT...

AT 720 AM CDT...DOPPLER RADAR ESTIMATES 4 TO 7 INCHES OF RAIN FELL 
OVERNIGHT INTO EARLY THIS MORNING. 

THUNDERSTORMS HAVE TAPERED OFF ACROSS THE AREA BUT WATER LEVELS WILL 
REMAIN HIGH. THE FLASH FLOOD WARNING WILL BE REPLACED WITH AN AREAL 
FLOOD WARNING AT 730 AM CDT.

RUNOFF FROM THIS EXCESSIVE RAINFALL WILL CAUSE FLOODING TO OCCUR. 
SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE...
ELKADER...GUTTENBERG...EDGEWOOD...GARNAVILLO...STRAWBERRY POINT AND 
VOLGA.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

MOST FLOOD RELATED DEATHS OCCUR IN VEHICLES. DO NOT ATTEMPT TO CROSS
BRIDGES...DIPS...OR OTHER LOW SPOTS IF WATER COVERS THE ROADWAY.
NEVER TRY TO CROSS A FLOWING STREAM...EVEN A SMALL ONE...ON FOOT OR
IN A VEHICLE.

&&

LAT...LON 4265 9161 4292 9161 4293 9161 4288 9112
      4286 9109 4274 9105 4268 9095 4268 9090
      4265 9089 4264 9108

$$

JW

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 28, 4:24 AM CDT	Flash Flood Warning	ARX	Fayette	3 hr
Jul 28, 7:27 AM CDT	Areal Flood Warning	ARX	Clayton, Fayette	6 hr
Jul 28, 7:58 AM CDT	River Flood Warning	ARX	Clayton	13 hr

Nearby

Flash Flood Warnings in Iowa, 2011 Every flash flood warning in 2011

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.