Alert archive / Iowa / Flash Flood Warnings in 2021

Flash Flood Warning 2, NWS La Crosse, WI

June 29, 2021Allamakee County, Iowa; Crawford County, Wisconsin

NWS La Crosse, WI issued this flash flood warning at Jun 29, 2021, 1:21 PM CDT for Allamakee County, Iowa; Crawford County, Wisconsin. It was in force for 3 hr. 5 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
Jun 29, 2021, 1:21 PM CDT (18:21 UTC)
Expired
Jun 29, 2021, 4:30 PM CDT
In force
3 hr
Issued by
NWS La Crosse, WI
Area
Storm-based polygon
Flood severity
None

Counties Allamakee County, IA, Crawford County, WI

The radar

The La Crosse radar (KARX), 71 km from the middle of the area, began a volume at 18:21 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
Jun 29, 1:25 PM CDTFLASH FLOOD6 Wsw Eastman, WICORRECTED ROAD NAME FROM PREVIOUS LSR. HWY 35 CLOSED BETWEEN COUNTY ROAD D AND COUNTY ROAD K DUE TO HIGH WATER, MUD AND ROCKSLIDES.
Jun 29, 1:25 PM CDTFLASH FLOOD6 Wsw Eastman, WIHWY 35 CLOSED BETWEEN COUNTY ROAD D AND COUNTY ROAD N DUE TO HIGH WATER, MUD AND ROCKSLIDES.
Jun 29, 1:30 PM CDTFLASH FLOODWaukon Jct, IAMUDSLIDES, FLOODED ROADS, AND FLOWING WATERS.
Jun 29, 3:25 PM CDTHEAVY RAIN 4.755 Wsw Eastman, WIRAIN FOR TODAY SO FAR.
Jun 29, 4:22 PM CDTHEAVY RAIN 4.18Eastman, WI

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 12:00Z, 6.4 hours before the alert went out and 182 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 12:00Z on 2021-06-29Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 403 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 12:00Z on 2021-06-29The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -1 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
403 J/kg
Mixed-layer CIN
-20 J/kg
Mixed-layer LCL
837 m above ground
0-6 km bulk shear
33 kt
0-1 km storm-relative helicity
-1 m²/s²
0-3 km storm-relative helicity
95 m²/s²
Significant tornado parameter
-0.0
Supercell composite
-0.4

Open this sounding in Storm Lab

The text

As transmitted.

662 
WGUS53 KARX 291821
FFWARX
IAC005-WIC023-292130-
/O.NEW.KARX.FF.W.0002.210629T1821Z-210629T2130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service La Crosse WI
121 PM CDT Tue Jun 29 2021

The National Weather Service in La Crosse has issued a

* Flash Flood Warning for...
  Southern Allamakee County in northeastern Iowa...
  Central Crawford County in southwestern Wisconsin...

* Until 430 PM CDT.

* At 121 PM CDT, local law enforcement reported thunderstorms 
  producing heavy rain in Waukon Junction. Between 1 and 3 inches of 
  rain have fallen. Additional rainfall amounts of 1 to 2 inches are 
  possible in the warned area. Flash flooding is ongoing or expected 
  to begin shortly.

  HAZARD...Flash flooding caused by thunderstorms.

  SOURCE...Law enforcement reported.

  IMPACT...Flash flooding of small creeks and streams, urban
           areas, highways, streets and underpasses as well as
           other poor drainage and low-lying areas.

* Some locations that will experience flash flooding include...
  Postville, Harpers Ferry, Eastman, Steuben, and Waukon Jct.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

In hilly terrain there are hundreds of low water crossings which are 
potentially dangerous in heavy rain. Do not attempt to cross flooded 
roads. Find an alternate route.

&&

LAT...LON 4321 9158 4328 9091 4332 9068 4318 9068
      4315 9086 4307 9108 4309 9161

FLASH FLOOD...OBSERVED

$$

Shea
4 follow-up statements
062 
WGUS73 KARX 291842
FFSARX

Flash Flood Statement
National Weather Service La Crosse WI
142 PM CDT Tue Jun 29 2021

IAC005-WIC023-292130-
/O.CON.KARX.FF.W.0002.000000T0000Z-210629T2130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Allamakee IA-Crawford WI-
142 PM CDT Tue Jun 29 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 430 PM CDT THIS 
AFTERNOON FOR SOUTHERN ALLAMAKEE AND CENTRAL CRAWFORD COUNTIES...

At 142 PM CDT, local law enforcement reported thunderstorms 
producing heavy rain in Waukon Junction Iowa and into Crawford 
County Wisconsin. Between 1 and 3 inches of rain has fallen. There 
were reports of mudslides and high water in many areas, including 
closure of Highway 35 north of Prairie du Chien.

HAZARD...Flash flooding caused by thunderstorms.

SOURCE...Law enforcement reported.

IMPACT...Flash flooding of small creeks and streams, urban areas,
         highways, streets and underpasses as well as other poor
         drainage and low-lying areas.

Some locations that will experience flash flooding include...
  Postville, Harpers Ferry, Eastman, Steuben, and Waukon Jct.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

In hilly terrain there are hundreds of low water crossings which are 
potentially dangerous in heavy rain. Do not attempt to cross flooded 
roads. Find an alternate route.

&&

LAT...LON 4321 9158 4328 9091 4332 9068 4318 9068
      4315 9086 4307 9108 4309 9161

FLASH FLOOD...OBSERVED

$$

Shea
736 
WGUS73 KARX 291911
FFSARX

Flash Flood Statement
National Weather Service La Crosse WI
211 PM CDT Tue Jun 29 2021

IAC005-WIC023-292130-
/O.CON.KARX.FF.W.0002.000000T0000Z-210629T2130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Allamakee IA-Crawford WI-
211 PM CDT Tue Jun 29 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 430 PM CDT THIS 
AFTERNOON FOR SOUTHERN ALLAMAKEE AND CENTRAL CRAWFORD COUNTIES...

At 211 PM CDT, flash flooding was occurring in southern parts of 
Allamakee County Iowa and central parts of Crawford County 
Wisconsin, north of Prairie du Chien. There have been reports of 
mudslides and road closures from high water from both emergency 
management and law enforcement in the area. The good news is 
thunderstorms have decreased in that area lessening the threat for 
additional heavy rain.

HAZARD...Flash flooding caused by thunderstorms.

SOURCE...Law enforcement reported.

IMPACT...Flash flooding of small creeks and streams.

Some locations that will experience flash flooding include...
  Postville, Harpers Ferry, Eastman, Steuben, and Waukon Jct.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

In hilly terrain there are hundreds of low water crossings which are 
potentially dangerous in heavy rain. Do not attempt to cross flooded 
roads. Find an alternate route.

&&

LAT...LON 4321 9158 4328 9091 4332 9068 4318 9068
      4315 9086 4307 9108 4309 9161

FLASH FLOOD...OBSERVED

$$

Shea
095 
WGUS73 KARX 292046
FFSARX

Flash Flood Statement
National Weather Service La Crosse WI
346 PM CDT Tue Jun 29 2021

IAC005-WIC023-292130-
/O.CON.KARX.FF.W.0002.000000T0000Z-210629T2130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Allamakee IA-Crawford WI-
346 PM CDT Tue Jun 29 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 430 PM CDT THIS 
AFTERNOON FOR SOUTHERN ALLAMAKEE AND CENTRAL CRAWFORD COUNTIES...

At 346 PM CDT, Doppler radar indicated thunderstorms producing heavy 
rain across the warned area where law enforcement has already 
reported flash flooding. Between 1 and 3 inches of rain have fallen 
so far. Additional rainfall amounts up to 1 inch are possible as 
more thunderstorms track through the warned area.

HAZARD...Flash flooding caused by thunderstorms.

SOURCE...Law enforcement reported.

IMPACT...Flash flooding of small creeks and streams, urban areas,
         highways, streets and underpasses as well as other poor
         drainage and low-lying areas. Rock and mudslides are
         possible.

Some locations that will experience flash flooding include...
  Prairie Du Chien, Postville, Harpers Ferry, Seneca, Eastman, 
  Waterville, Lynxville, Steuben, Bell Center, Highway 35 And County 
  D, Andy Mountain Campground, Waukon Jct, Limery Ridge, Hazen 
  Corners, Eldergrove, Effigy Mounds, Lock And Dam 9, Yellow River 
  State Forest, Highway 27 And County F and Sixteen.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

In hilly terrain there are hundreds of low water crossings which are 
potentially dangerous in heavy rain. Do not attempt to cross flooded 
roads. Find an alternate route.

&&

LAT...LON 4321 9158 4328 9091 4332 9068 4318 9068
      4315 9086 4307 9108 4309 9161

FLASH FLOOD...OBSERVED

$$

Kurz
869 
WGUS73 KARX 292122
FFSARX

Flash Flood Statement
National Weather Service La Crosse WI
422 PM CDT Tue Jun 29 2021

IAC005-WIC023-292132-
/O.EXP.KARX.FF.W.0002.000000T0000Z-210629T2130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Allamakee IA-Crawford WI-
422 PM CDT Tue Jun 29 2021

...FLASH FLOOD WARNING WILL EXPIRE AT 430 PM CDT THIS AFTERNOON FOR 
SOUTHERN ALLAMAKEE AND CENTRAL CRAWFORD COUNTIES...

Flood waters have receded. Additional isolated thunderstorms are not 
expected to pose any threat for continued flooding, therefore the 
flash flood warning will be allowed to expire.

LAT...LON 4321 9158 4328 9091 4332 9068 4318 9068
      4315 9086 4307 9108 4309 9161

$$

Kurz

The office that day

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

IssuedProductOfficeCountiesLasted
Jun 29, 12:28 PM CDTAreal Flood AdvisoryARXAllamakee53 min
Jun 29, 2:50 PM CDTSpecial Weather StatementARXAllamakee40 min
Jun 29, 3:22 PM CDTAreal Flood AdvisoryARXAllamakee68 min
Jun 29, 3:25 PM CDTTornado WarningARXAllamakee65 min
Jun 29, 1:31 PM CDTSpecial Weather StatementARXBuffalo, Clark59 min
Jun 29, 2:29 PM CDTSpecial Weather StatementARXClark31 min
Jun 29, 4:29 PM CDTSpecial Weather StatementARXLa Crosse31 min
Jun 29, 4:59 PM CDTSpecial Weather StatementARXLa Crosse, Monroe61 min
Jun 29, 5:50 PM CDTSpecial Weather StatementARXJuneau55 min

Nearby

Flash Flood Warnings in Iowa, 2021Flash Flood Warnings in Wisconsin, 2021Every flash flood warning in 2021

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.