Alert archive / Iowa / Flash Flood Warnings in 2021
Flash Flood Warning 9, NWS La Crosse, WI
NWS La Crosse, WI issued this flash flood warning at Aug 27, 2021, 11:12 PM CDT for Chickasaw County, Floyd County, 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 27, 2021, 11:12 PM CDT (04:12 UTC)
- Expired
- Aug 28, 2021, 5:15 AM CDT
- In force
- 6 hr
- Issued by
- NWS La Crosse, WI
- Area
- Storm-based polygon
- Flood severity
- None
Counties Chickasaw County, IA, Floyd County, IA
The radar
The La Crosse radar (KARX), 140 km from the middle of the area, began a volume at 04:10 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 |
|---|---|---|---|
| Aug 28, 1:36 AM CDT | FLASH FLOOD | Alta Vista, IA | ROADS AROUND THE TOWN OF ALTA VISTA ARE IMPASSABLE. |
| Aug 28, 1:37 AM CDT | FLASH FLOOD | New Hampton, IA | ROADS THROUGHOUT THE TOWN OF NEW HAMPTION REPORTED TO BE FLOODED. |
Local storm reports filed while the alert was in force, from inside its polygon or its counties.
The nearest sounding before it
Minneapolis, MN (KMPX), launched 00:00Z, 4.2 hours before the alert went out and 219 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.
- Mixed-layer CAPE
- 652 J/kg
- Mixed-layer CIN
- -66 J/kg
- Mixed-layer LCL
- 643 m above ground
- 0-6 km bulk shear
- 45 kt
- 0-1 km storm-relative helicity
- 140 m²/s²
- 0-3 km storm-relative helicity
- 175 m²/s²
- Significant tornado parameter
- 0.5
- Supercell composite
- 3.5
The text
As transmitted.
988
WGUS53 KARX 280412
FFWARX
IAC037-067-280715-
/O.NEW.KARX.FF.W.0009.210828T0412Z-210828T0715Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service La Crosse WI
1112 PM CDT Fri Aug 27 2021
The National Weather Service in La Crosse has issued a
* Flash Flood Warning for...
Floyd County in north central Iowa...
Chickasaw County in northeastern Iowa...
* Until 215 AM CDT.
* At 1112 PM CDT, Doppler radar and automated rain gauges indicated
thunderstorms producing heavy rain across the warned area. Between
2 and 3 inches of rain have fallen. Additional rainfall amounts of
1 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...
Charles City, New Hampton, Nashua, Fredericksburg, and Lawler.
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 4291 9276 4321 9302 4321 9208 4291 9208
FLASH FLOOD...RADAR AND GAUGE INDICATED
$$
KDS4 follow-up statements
525
WGUS53 KARX 280635
FFWARX
IAC037-067-280815-
/O.EXT.KARX.FF.W.0009.000000T0000Z-210828T0815Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service La Crosse WI
135 AM CDT Sat Aug 28 2021
The National Weather Service in La Crosse has extended the
* Flash Flood Warning for...
Floyd County in north central Iowa...
Chickasaw County in northeastern Iowa...
* Until 315 AM CDT.
* At 135 AM CDT, local law enforcement reported thunderstorms
producing flash flooding across the warned area. Between 3 and 5
inches of rain have fallen. Additional rainfall amounts of 1 to 2
inches are possible in the warned area. Flash flooding is already
occurring.
HAZARD...Flash flooding caused by thunderstorms.
SOURCE...Law enforcement reported that roads around the towns
of Alta Vista and New Hampton are flooded and
impassable in many locations.
IMPACT...Flash flooding of small creeks and streams, urban
areas, highways, streets and underpasses as well as
other poor drainage and low-lying areas.
* Some locations that will experience flash flooding include...
Charles City, New Hampton, Nashua, Fredericksburg, Lawler, Rudd,
Floyd, Ionia, Protivin, Jerico, Chickasaw, Alta Vista.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.
Be especially cautious at night when it is harder to recognize the
dangers of flooding.
&&
LAT...LON 4291 9276 4321 9302 4321 9208 4291 9208
FLASH FLOOD...OBSERVED
$$
KDS621
WGUS73 KARX 280728
FFSARX
Flash Flood Statement
National Weather Service La Crosse WI
228 AM CDT Sat Aug 28 2021
IAC037-067-280815-
/O.CON.KARX.FF.W.0009.000000T0000Z-210828T0815Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Chickasaw IA-Floyd IA-
228 AM CDT Sat Aug 28 2021
...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 315 AM CDT EARLY THIS
MORNING FOR EASTERN FLOYD AND CHICKASAW COUNTIES...
At 228 AM CDT, local law enforcement reported flash flooding across
the warned area. Between 3 and 6 inches of rain have fallen.
Additional rainfall amounts up to 1 inch are possible in the warned
area. Flash flooding is already occurring.
HAZARD...Flash flooding caused by thunderstorms.
SOURCE...Law enforcement reported that roads around the towns of
Alta Vista and New Hampton are flooded and impassable in
many locations.
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...
Charles City, New Hampton, Nashua, Fredericksburg, Lawler, Ionia,
Protivin, Jerico, Chickasaw, and Alta Vista.
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 4291 9257 4321 9278 4321 9208 4317 9208
4316 9208 4313 9208 4312 9208 4310 9208
4308 9208 4304 9208 4302 9208 4301 9208
4299 9208 4297 9208 4292 9208 4291 9208
FLASH FLOOD...OBSERVED
$$
KDS276
WGUS53 KARX 280749
FFWARX
IAC037-067-281015-
/O.EXT.KARX.FF.W.0009.000000T0000Z-210828T1015Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service La Crosse WI
249 AM CDT Sat Aug 28 2021
The National Weather Service in La Crosse has extended the
* Flash Flood Warning for...
Northeastern Floyd County in north central Iowa...
Chickasaw County in northeastern Iowa...
* Until 515 AM CDT.
* At 249 AM CDT, local law enforcement reported flash flooding
across the warned area. Between 3 and 6 inches of rain have
fallen. Flash flooding is already occurring.
HAZARD...Flash flooding caused by thunderstorms.
SOURCE...Law enforcement reported that roads around the towns
of Alta Vista and New Hampton are flooded and
impassable in many locations.
IMPACT...Flash flooding of small creeks and streams, urban
areas, highways, streets and underpasses as well as
other poor drainage and low-lying areas.
* Some locations that will experience flash flooding include...
Charles City, New Hampton, Nashua, Fredericksburg, Lawler, Ionia,
Protivin, Jerico, Chickasaw, and Alta Vista.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.
Be especially cautious at night when it is harder to recognize the
dangers of flooding.
&&
LAT...LON 4321 9268 4321 9208 4317 9208 4316 9208
4313 9208 4312 9208 4310 9208 4308 9208
4304 9208 4302 9208 4301 9208 4299 9208
4297 9208 4292 9208 4291 9208 4292 9241
FLASH FLOOD...OBSERVED
$$
KDS952
WGUS73 KARX 281008 RRA
FFSARX
Flash Flood Statement
National Weather Service La Crosse WI
508 AM CDT Sat Aug 28 2021
IAC037-067-281018-
/O.EXP.KARX.FF.W.0009.000000T0000Z-210828T1015Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Chickasaw IA-Floyd IA-
508 AM CDT Sat Aug 28 2021
...FLASH FLOOD WARNING WILL EXPIRE AT 515 AM CDT EARLY THIS MORNING
FOR NORTHEASTERN FLOYD AND CHICKASAW COUNTIES...
Heavy rain has ended over the warned area. Please continue to heed
remaining road closures.
LAT...LON 4321 9268 4321 9208 4317 9208 4316 9208
4313 9208 4312 9208 4310 9208 4308 9208
4304 9208 4302 9208 4301 9208 4299 9208
4297 9208 4292 9208 4291 9208 4292 9241
$$
DTJThe office that day
Everything else NWS La Crosse, WI issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 27, 7:04 PM CDT | Areal Flood Advisory | ARX | Chickasaw, Howard | 116 min |
| Aug 27, 7:29 PM CDT | Severe Thunderstorm Warning | ARX | Allamakee, Clayton, Winneshiek | 46 min |
| Aug 27, 7:38 PM CDT | Flash Flood Watch | ARX | Allamakee, Chickasaw, Clayton, Fayette, Floyd, Howard and 2 more | 18 hr |
| Aug 27, 8:03 PM CDT | Severe Thunderstorm Warning | ARX | Clayton | 42 min |
| Aug 27, 8:09 PM CDT | Severe Thunderstorm Warning | ARX | Mitchell | 25 min |
| Aug 27, 8:45 PM CDT | Flash Flood Warning | ARX | Howard, Mitchell | 9 hr |
| Aug 27, 10:26 PM CDT | Special Weather Statement | ARX | Chickasaw, Howard, Winneshiek | 34 min |
| Aug 27, 11:07 PM CDT | Special Weather Statement | ARX | Winneshiek | 23 min |
| Aug 28, 1:16 AM CDT | Flash Flood Warning | ARX | Fayette, Winneshiek | 4 hr |
| Aug 28, 3:00 AM CDT | Special Weather Statement | ARX | Clayton | 30 min |
| Aug 28, 3:06 AM CDT | River Flood Warning | ARX | Clayton | 3 days |
| Aug 28, 3:06 AM CDT | River Flood Warning | ARX | Clayton | 3 days |
| Aug 28, 4:05 AM CDT | River Flood Warning | ARX | Floyd | 70 hr |
| Aug 28, 9:39 AM CDT | Areal Flood Warning | ARX | Chickasaw, Fayette, Floyd, Howard, Mitchell, Winneshiek | 30 hr |
Nearby
Flash Flood Warnings in Iowa, 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.