Alert archive / Iowa / Flash Flood Warnings in 2017

Flash Flood Warning 6, NWS La Crosse, WI

July 11, 2017Clayton County, Iowa

NWS La Crosse, WI issued this flash flood warning at Jul 11, 2017, 10:14 PM CDT for Clayton County, Iowa. It was in force for 6 hr. 7 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 11, 2017, 10:14 PM CDT (03:14 UTC)
Expired: Jul 12, 2017, 4:15 AM CDT
In force: 6 hr
Issued by: NWS La Crosse, WI
Area: Storm-based polygon
Emergency: Flash flood emergency
Flood severity: None

County Clayton County, IA

The radar

The La Crosse radar (KARX), 122 km from the middle of the area, began a volume at 03:14 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 11, 11:26 PM CDT	FLASH FLOOD	4 Sse Osterdock, IA	LAW ENFORCEMENT ARE EVACUATING RESIDENTS ALONG THE LITTLE TURKEY RIVER AND MILL CREEK SOUTHEAST OF OSTERDOCK, IA.
Jul 12, 1:03 AM CDT	HEAVY RAIN 5.48	Guttenberg, IA	RAINFALL THROUGH 1 AM. REPORT RELAYED VIA BROADCAST MEDIA.
Jul 12, 1:06 AM CDT	HEAVY RAIN 8.2	1 N Osterdock, IA	REPORT RELAYED VIA BROADCAST MEDIA.
Jul 12, 1:06 AM CDT	HEAVY RAIN 8.2	Osterdock, IA	REPORT RELAYED VIA BROADCAST MEDIA.
Jul 12, 2:35 AM CDT	HEAVY RAIN 8.25	4 W North Buena Vista, IA	RELAYED VIA LAW ENFORCEMENT.
Jul 12, 2:39 AM CDT	FLASH FLOOD	Garber, IA	MANY ROADS WASHED OUT IN SOUTHEAST PART OF COUNTY.
Jul 12, 3:15 AM CDT	HEAVY RAIN 5.39	Garber, IA	MESONET STATION GRBI4, GARBER.

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, 3.2 hours before the alert went out and 132 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: 1096 J/kg
Mixed-layer CIN: -33 J/kg
Mixed-layer LCL: 755 m above ground
0-6 km bulk shear: 44 kt
0-1 km storm-relative helicity: 268 m²/s²
0-3 km storm-relative helicity: 315 m²/s²
Significant tornado parameter: 1.5
Supercell composite: 7.6

Open this sounding in Storm Lab

The text

As transmitted.

480 
WGUS53 KARX 120314
FFWARX
IAC043-120615-
/O.NEW.KARX.FF.W.0006.170712T0314Z-170712T0615Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service La Crosse WI
1014 PM CDT TUE JUL 11 2017

The National Weather Service in La Crosse has issued a

* Flash Flood Warning for...
  Southeastern Clayton County in northeastern Iowa...

* Until 115 AM CDT

* At 1012 PM CDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. As much as 3 to 5 inches of 
  rain have fallen. Flash flooding is expected to begin shortly.

* Additional rain amounts of one-half up to 2 inches are likely in 
  much of the warning area. 

* Some locations that will experience flooding include...
  Guttenberg, Cassville, North Buena Vista, Garber, Osterdock, 
  Elkport, Millville, Turkey River, Fairview, Lock And Dam 10.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles. 

&&

LAT...LON 4284 9142 4282 9108 4277 9107 4276 9106
      4275 9107 4274 9105 4274 9104 4272 9102
      4272 9100 4269 9097 4268 9094 4268 9092
      4267 9090 4265 9090 4265 9123

$$

RRS

3 follow-up statements

237 
WGUS53 KARX 120442 RRA
FFWARX
IAC043-120915-
/O.EXT.KARX.FF.W.0006.000000T0000Z-170712T0915Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service La Crosse WI
1142 PM CDT TUE JUL 11 2017

...FLASH FLOOD EMERGENCY FOR AREAS SOUTH OF OSTERDOCK...

The National Weather Service in La Crosse has extended the

* Flash Flood Warning for...
  Southeastern Clayton County in northeastern Iowa...

* Until 415 AM CDT

* At 1133 PM CDT, local law enforcement reported heavy rain across 
  the warned area. Up to 6 inches of rain have fallen. Flash 
  flooding is already occurring.

* This is a FLASH FLOOD EMERGENCY for residents along the Little 
  Turkey River and Mill Creek south of Osterdock where local law 
  enforcement are evacuating homes taking on water. This is a 
  PARTICULARLY DANGEROUS SITUATION. SEEK HIGHER GROUND NOW! 

* Additional rainfall amounts of 1 to 3 inches are possible in the 
  warned area, resulting in additional flash flooding across much of 
  southeast Clayton County.

* Some locations that will experience flooding include...
  Guttenberg, Cassville, North Buena Vista, Garber, Osterdock,
  Elkport, and Millville.

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.

Move to higher ground now. Act quickly to protect your life.

Be especially cautious at night when it is harder to recognize the
dangers of flooding.

&&

LAT...LON 4284 9142 4282 9108 4277 9107 4276 9106
      4275 9107 4274 9105 4274 9104 4272 9102
      4272 9100 4269 9097 4268 9094 4268 9092
      4267 9090 4265 9090 4265 9123

$$

Rogers

276 
WGUS73 KARX 120622 RRA
FFSARX

Flash Flood Statement
National Weather Service La Crosse WI
122 AM CDT WED JUL 12 2017

IAC043-120915-
/O.CON.KARX.FF.W.0006.000000T0000Z-170712T0915Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Clayton IA-
122 AM CDT WED JUL 12 2017

...THIS IS A FLASH FLOOD EMERGENCY FOR AREAS SOUTH OF OSTERDOCK...

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 415 AM CDT FOR
SOUTHEASTERN CLAYTON COUNTY...

At 116 AM CDT, public reported over 8 inches of rainfall in 
Osterdock with around 5 1/2 inches in Guttenberg. Flash 
flooding is occurring.

This is a FLASH FLOOD EMERGENCY for residents along the Little 
Turkey River and Mill Creek south of Osterdock where local law 
enforcement are evacuating homes taking on water. This is a 
PARTICULARLY DANGEROUS SITUATION. SEEK HIGHER GROUND NOW!

Some locations that will experience flooding include...
Guttenberg, Cassville, North Buena Vista, Garber, Osterdock, Elkport,
Millville, Turkey River, Fairview, Lock And Dam 10, Motor, County
Roads X 47 And C 7 X and Updegraff.

Additional rainfall amounts of 1 to 2 inches, locally higher, are 
possible in the warned area.

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.

Move to higher ground now. Act quickly to protect your life.

Be especially cautious at night when it is harder to recognize the
dangers of flooding.

&&

LAT...LON 4284 9142 4282 9108 4277 9107 4276 9106
      4275 9107 4274 9105 4274 9104 4272 9102
      4272 9100 4269 9097 4268 9094 4268 9092
      4267 9090 4265 9090 4265 9123

$$

Rieck

799 
WGUS73 KARX 120820
FFSARX

Flash Flood Statement
National Weather Service La Crosse WI
320 AM CDT WED JUL 12 2017

IAC043-120915-
/O.CON.KARX.FF.W.0006.000000T0000Z-170712T0915Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Clayton IA-
320 AM CDT WED JUL 12 2017

...THIS IS A FLASH FLOOD EMERGENCY FOR AREAS SOUTH OF OSTERDOCK...

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 415 AM CDT FOR
SOUTHEASTERN CLAYTON COUNTY...

At 307 AM CDT, local law enforcement reported many washouts on 
smaller and secondary roads. Evacuations have halted. 8.25 inches of 
rain was reported near Millville. Flash flooding is already 
occurring.

This is a FLASH FLOOD EMERGENCY for residents along the Little 
Turkey River and Mill Creek south of Osterdock.

The bulk of the rainfall has exited east, with only small chances 
for additional rain through the rest of the morning hours. 

Some locations that will experience flooding include...
Guttenberg, Cassville, North Buena Vista, Garber, Osterdock, Elkport,
Millville, Turkey River, Fairview, Lock And Dam 10, Motor, County
Roads X 47 And C 7 X and Updegraff.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Move to higher ground now. Act quickly to protect your life.

Be especially cautious at night when it is harder to recognize the
dangers of flooding.

&&

LAT...LON 4284 9142 4282 9108 4277 9107 4276 9106
      4275 9107 4274 9105 4274 9104 4272 9102
      4272 9100 4269 9097 4268 9094 4268 9092
      4267 9090 4265 9090 4265 9123

$$

Rieck

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 11, 7:46 PM CDT	Special Weather Statement	ARX	Clayton	44 min
Jul 11, 8:35 PM CDT	Special Weather Statement	ARX	Clayton	70 min
Jul 11, 9:14 PM CDT	Special Weather Statement	ARX	Allamakee	46 min
Jul 11, 9:19 PM CDT	Tornado Warning	ARX	Clayton	26 min
Jul 11, 9:26 PM CDT	Areal Flood Advisory	ARX	Clayton, Fayette	3 hr
Jul 11, 9:44 PM CDT	Severe Thunderstorm Warning	ARX	Clayton	61 min
Jul 11, 10:12 PM CDT	Tornado Warning	ARX	Clayton	18 min
Jul 12, 1:40 AM CDT	River Flood Warning	ARX	Clayton	24 hr
Jul 12, 1:40 AM CDT	River Flood Warning	ARX	Clayton	24 hr
Jul 12, 4:22 AM CDT	Areal Flood Warning Emergency	ARX	Clayton	6 hr
Jul 12, 8:44 AM CDT	Special Weather Statement	ARX	Chickasaw, Clayton, Fayette	31 min
Jul 12, 9:13 AM CDT	Special Weather Statement	ARX	Clayton	17 min
Jul 12, 9:18 AM CDT	Severe Thunderstorm Warning	ARX	Clayton	42 min
Jul 12, 9:44 AM CDT	Severe Thunderstorm Warning	ARX	Clayton	22 min
Jul 12, 10:12 AM CDT	Areal Flood Warning	ARX	Clayton	3 hr
Jul 12, 5:46 PM CDT	Severe Thunderstorm Warning	ARX	Fayette	26 min

Nearby

Flash Flood Warnings in Iowa, 2017 Every flash flood warning in 2017

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.