Alert archive / Iowa / Flash Flood Warnings in 2021

Flash Flood Warning 6, NWS La Crosse, WI

August 27, 2021Howard County, Mitchell County, Iowa; Fillmore County, Mower County, Minnesota

NWS La Crosse, WI issued this flash flood warning at Aug 27, 2021, 1:51 AM CDT for Howard County, Mitchell County, Iowa; Fillmore County, Mower County, Minnesota. It was in force for 4 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
Aug 27, 2021, 1:51 AM CDT (06:51 UTC)
Expired
Aug 27, 2021, 5:45 AM CDT
In force
4 hr
Issued by
NWS La Crosse, WI
Area
Storm-based polygon
Flood severity
None

Counties Howard County, IA, Mitchell County, IA, Fillmore County, MN, Mower County, MN

The radar

The La Crosse radar (KARX), 133 km from the middle of the area, began a volume at 06:51 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

Minneapolis, MN (KMPX), launched 00:00Z, 6.9 hours before the alert went out and 160 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, Minneapolis, MN at 00:00Z on 2021-08-27Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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, Minneapolis, MN at 00:00Z on 2021-08-27The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 393 square meters per square second.19395878Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
792 m above ground
0-6 km bulk shear
49 kt
0-1 km storm-relative helicity
393 m²/s²
0-3 km storm-relative helicity
392 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.1

Open this sounding in Storm Lab

The text

As transmitted.

343 
WGUS53 KARX 270651
FFWARX
IAC089-131-MNC045-099-271045-
/O.NEW.KARX.FF.W.0006.210827T0651Z-210827T1045Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service La Crosse WI
151 AM CDT Fri Aug 27 2021

The National Weather Service in La Crosse has issued a

* Flash Flood Warning for...
  Northern Mitchell County in north central Iowa...
  Northwestern Howard County in northeastern Iowa...
  Southwestern Fillmore County in southeastern Minnesota...
  Southern Mower County in southeastern Minnesota...

* Until 545 AM CDT.

* At 151 AM CDT, Doppler radar and automated rain gauges indicated 
  thunderstorms producing heavy rain across the warned area. Between 
  2 and 3.5 inches of rain have fallen. Additional rainfall amounts 
  of 2 to 3 inches are possible in the warned area. Flash flooding 
  is ongoing or expected to begin shortly.

  HAZARD...Flash flooding caused by thunderstorms.

  SOURCE...Radar and automated gauges.

  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...
  Le Roy, Adams, Lyle, Lime Springs, Stacyville, Rose Creek, Cherry 
  Grove, York, Ostrander, and Chester.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

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

&&

LAT...LON 4359 9305 4362 9245 4363 9227 4350 9223
      4346 9222 4343 9302 4349 9302 4350 9302
      4350 9305 4353 9305 4356 9305

FLASH FLOOD...RADAR AND GAUGE INDICATED

$$

KDS
2 follow-up statements
965 
WGUS73 KARX 271021
FFSARX

Flash Flood Statement
National Weather Service La Crosse WI
521 AM CDT Fri Aug 27 2021

IAC089-131-MNC045-099-271045-
/O.CON.KARX.FF.W.0006.000000T0000Z-210827T1045Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Howard IA-Mitchell IA-Fillmore MN-Mower MN-
521 AM CDT Fri Aug 27 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 545 AM CDT EARLY THIS 
MORNING FOR NORTHERN MITCHELL, NORTHWESTERN HOWARD, SOUTHWESTERN 
FILLMORE AND SOUTHERN MOWER COUNTIES...

At 521 AM CDT, local law enforcement reported high water was 
receding across the warned area. Between 2 and 5 inches of rain have 
fallen. Additional rainfall amounts up to 1 inch are possible in 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.

Some locations that will experience flash flooding include...
  Le Roy, Adams, Lyle, Lime Springs, Stacyville, Rose Creek, Cherry 
  Grove, York, Ostrander, Chester, Taopi, Bailey, County Roads 4 And 
  8, Meyer, Lake Louise State Park, Johnsburg, County V 10 And 40th 
  Street, County Roads 4 And 3, County Roads 56 And 5 and 
  Toeterville.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

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

&&

LAT...LON 4359 9305 4362 9245 4363 9227 4350 9223
      4346 9222 4343 9302 4349 9302 4350 9302
      4350 9305 4353 9305 4356 9305

FLASH FLOOD...OBSERVED

$$

Kurz
199 
WGUS73 KARX 271037
FFSARX

Flash Flood Statement
National Weather Service La Crosse WI
537 AM CDT Fri Aug 27 2021

IAC089-131-MNC045-099-271047-
/O.EXP.KARX.FF.W.0006.000000T0000Z-210827T1045Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Howard IA-Mitchell IA-Fillmore MN-Mower MN-
537 AM CDT Fri Aug 27 2021

...FLASH FLOOD WARNING WILL EXPIRE AT 545 AM CDT THIS MORNING FOR 
NORTHERN MITCHELL, NORTHWESTERN HOWARD, SOUTHWESTERN FILLMORE AND 
SOUTHERN MOWER COUNTIES...

Heavy rain is ending and flood waters have receded. Flooding is no 
longer expected to pose a threat. Please continue to heed any 
remaining road closures.

A Flood Watch remains in effect until 700 AM CDT for portions of 
Iowa and southeast Minnesota.

LAT...LON 4359 9305 4362 9245 4363 9227 4350 9223
      4346 9222 4343 9302 4349 9302 4350 9302
      4350 9305 4353 9305 4356 9305

$$

Kurz

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 27, 3:33 AM CDTFlash Flood WarningARXHoward, Mitchell, Winneshiek4 hr
Aug 27, 9:42 AM CDTRiver Flood WarningARXWinneshiek60 hr
Aug 27, 3:24 PM CDTSpecial Weather StatementARXHoward, Mitchell51 min
Aug 27, 5:34 PM CDTTornado WarningARXFloyd41 min
Aug 27, 6:09 PM CDTTornado Warning Tornado observedARXChickasaw, Floyd51 min
Aug 27, 6:45 PM CDTTornado Warning Tornado observedARXChickasaw, Fayette45 min
Aug 27, 6:52 PM CDTSevere Thunderstorm WarningARXAllamakee, Fayette, Winneshiek38 min
Aug 27, 2:55 PM CDTSpecial Weather StatementARXDodge, Olmsted, Wabasha50 min
Aug 27, 3:43 PM CDTSpecial Weather StatementARXOlmsted47 min

Nearby

Flash Flood Warnings in Iowa, 2021Flash Flood Warnings in Minnesota, 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.