Alert archive / Iowa / Flash Flood Watches in 2021
Flash Flood Watch 2, NWS La Crosse, WI
NWS La Crosse, WI issued this flash flood watch at Aug 27, 2021, 7:38 PM CDT for 8 counties in Iowa; 7 counties in Minnesota; Crawford County, Richland County, Vernon County, Wisconsin. It was in force for 18 hr.
The area
The counties it named.
The facts
- Issued
- Aug 27, 2021, 7:38 PM CDT (00:38 UTC)
- Expired
- Aug 28, 2021, 1:36 PM CDT
- In force
- 18 hr
- Issued by
- NWS La Crosse, WI
- Flood severity
- None
Counties Allamakee County, IA, Chickasaw County, IA, Clayton County, IA, Fayette County, IA, Floyd County, IA, Howard County, IA, Mitchell County, IA, Winneshiek County, IA, Dodge County, MN, Fillmore County, MN, Houston County, MN, Mower County, MN, Olmsted County, MN, Wabasha County, MN, Winona County, MN, Crawford County, WI, Richland County, WI, Vernon County, WI
The radar
The La Crosse radar (KARX), 69 km from the middle of the area, began a volume at 00:40 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, 0.6 hours before the alert went out and 203 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.
655 WGUS63 KARX 280038 FFAARX URGENT - IMMEDIATE BROADCAST REQUESTED Flood Watch National Weather Service La Crosse WI 738 PM CDT Fri Aug 27 2021 IAZ008>011-018-019-MNZ079-086>088-094>096-WIZ053>055-280945- /O.NEW.KARX.FF.A.0002.210828T0038Z-210828T1400Z/ /00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/ Mitchell-Howard-Winneshiek-Allamakee-Floyd-Chickasaw-Wabasha-Dodge- Olmsted-Winona-Mower-Fillmore-Houston-Vernon-Crawford-Richland- Including the cities of Osage, Cresco, Rochester, Waukon, Prairie Du Chien, Dodge Center, Austin, Preston, Viroqua, Richland Center, Winona, Decorah, New Hampton, Caledonia, Wabasha, and Charles City 738 PM CDT Fri Aug 27 2021 ...FLASH FLOOD WATCH IN EFFECT THROUGH SATURDAY MORNING... The National Weather Service in La Crosse has issued a * Flash Flood Watch for portions of Iowa, southeast Minnesota and southwest Wisconsin, including the following areas, in Iowa, Allamakee, Chickasaw, Floyd, Howard, Mitchell and Winneshiek. In southeast Minnesota, Dodge, Fillmore, Houston, Mower, Olmsted, Wabasha and Winona. In southwest Wisconsin, Crawford, Richland and Vernon. * Through Saturday morning. * Periods of thunderstorms are expected overnight. Heavy rainfall from these storms, along with wet soils from recent rainfall, will cause conditions favorable for flash flooding. Should storms repeat over the same areas, it appears a quick 1-3" of rain could fall and cause flash flooding. PRECAUTIONARY/PREPAREDNESS ACTIONS... You should monitor later forecasts and be prepared to take action should Flash Flood Warnings be issued. && $$ Baumgardt
4 follow-up statements
459 WGUS63 KARX 280852 FFAARX Flood Watch National Weather Service La Crosse WI 352 AM CDT Sat Aug 28 2021 IAZ008>011-018-019-MNZ079-086>088-094>096-WIZ053-281000- /O.CAN.KARX.FF.A.0002.000000T0000Z-210828T1400Z/ /00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/ Mitchell-Howard-Winneshiek-Allamakee-Floyd-Chickasaw-Wabasha- Dodge-Olmsted-Winona-Mower-Fillmore-Houston-Vernon- Including the cities of Osage, Cresco, Decorah, Waukon, Charles City, New Hampton, Wabasha, Dodge Center, Rochester, Winona, Austin, Preston, Caledonia, and Viroqua 352 AM CDT Sat Aug 28 2021 ...FLASH FLOOD WATCH IS CANCELLED... The Flash Flood Watch for portions of Iowa, southeast Minnesota, and southwest Wisconsin has been cancelled. $$ WIZ054-055-281400- /O.CON.KARX.FF.A.0002.000000T0000Z-210828T1400Z/ /00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/ Crawford-Richland- Including the cities of Prairie Du Chien and Richland Center 352 AM CDT Sat Aug 28 2021 ...FLASH FLOOD WATCH REMAINS IN EFFECT UNTIL 9 AM CDT THIS MORNING... The Flash Flood Watch continues for * A portion of southwest Wisconsin, including the following areas, Crawford and Richland. * Until 9 AM CDT this morning * Periods of thunderstorms are expected this morning. Heavy rainfall from these storms, along with wet soils from recent rainfall, will cause conditions favorable for flash flooding. PRECAUTIONARY/PREPAREDNESS ACTIONS... You should monitor later forecasts and be prepared to take action should Flash Flood Warnings be issued. && $$ Zapotocny
984 WGUS63 KARX 281209 FFAARX URGENT - IMMEDIATE BROADCAST REQUESTED Flood Watch National Weather Service La Crosse WI 709 AM CDT Sat Aug 28 2021 IAZ008>011-018-019-029-030-282015- /O.EXB.KARX.FF.A.0002.000000T0000Z-210828T2300Z/ /00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/ Mitchell-Howard-Winneshiek-Allamakee-Floyd-Chickasaw-Fayette-Clayton- Including the cities of Osage, Cresco, Waukon, Oelwein, Decorah, New Hampton, Elkader, and Charles City 709 AM CDT Sat Aug 28 2021 ...FLASH FLOOD WATCH IN EFFECT UNTIL 6 PM CDT THIS EVENING... The National Weather Service in La Crosse has expanded the * Flash Flood Watch to include portions of north central Iowa and northeast Iowa, including the following areas, in north central Iowa, Floyd and Mitchell. In northeast Iowa, Allamakee, Chickasaw, Clayton, Fayette, Howard and Winneshiek. * Until 6 PM CDT this evening. * Additional thunderstorms are expected at times today. Heavy rainfall from these storms, along with saturated soils from recent rain, will cause conditions favorable for flash flooding. PRECAUTIONARY/PREPAREDNESS ACTIONS... You should monitor later forecasts and be prepared to take action should Flash Flood Warnings be issued. && $$ WIZ054-055-282015- /O.EXT.KARX.FF.A.0002.000000T0000Z-210828T2300Z/ /00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/ Crawford-Richland- Including the cities of Richland Center and Prairie Du Chien 709 AM CDT Sat Aug 28 2021 ...FLASH FLOOD WATCH NOW IN EFFECT UNTIL 6 PM CDT THIS EVENING... The Flash Flood Watch is now in effect for * A portion of southwest Wisconsin, including the following areas, Crawford and Richland. * Until 6 PM CDT this evening. * Additional thunderstorms are expected at times today. Heavy rainfall from these storms, along with saturated soils from recent rain, will cause conditions favorable for flash flooding. PRECAUTIONARY/PREPAREDNESS ACTIONS... You should monitor later forecasts and be prepared to take action should Flash Flood Warnings be issued. && $$ Kurz
264 WGUS63 KARX 281449 FFAARX Flood Watch National Weather Service La Crosse WI 949 AM CDT Sat Aug 28 2021 IAZ008>011-018-019-029-030-WIZ054-055-282300- /O.CON.KARX.FF.A.0002.000000T0000Z-210828T2300Z/ /00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/ Mitchell-Howard-Winneshiek-Allamakee-Floyd-Chickasaw-Fayette-Clayton- Crawford-Richland- Including the cities of Osage, Cresco, Waukon, Oelwein, Richland Center, Prairie Du Chien, Decorah, New Hampton, Elkader, and Charles City 949 AM CDT Sat Aug 28 2021 ...FLASH FLOOD WATCH REMAINS IN EFFECT UNTIL 6 PM CDT THIS EVENING... The Flash Flood Watch continues for * Portions of Iowa and southwest Wisconsin, including the following areas, in Iowa, Allamakee, Chickasaw, Clayton, Fayette, Floyd, Howard, Mitchell and Winneshiek. In southwest Wisconsin, Crawford and Richland. * Until 6 PM CDT this evening. * Another area of showers and storms is moving into northeast Iowa that could make flooding problems worse. * Water will remain high that could lead to major river flooding and road closures. PRECAUTIONARY/PREPAREDNESS ACTIONS... You should monitor later forecasts and be prepared to take action should Flash Flood Warnings be issued. && $$ Shea
361 WGUS63 KARX 281836 FFAARX Flood Watch National Weather Service La Crosse WI 136 PM CDT Sat Aug 28 2021 IAZ008>011-018-019-029-030-WIZ054-055-281945- /O.CAN.KARX.FF.A.0002.000000T0000Z-210828T2300Z/ /00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/ Mitchell-Howard-Winneshiek-Allamakee-Floyd-Chickasaw-Fayette-Clayton- Crawford-Richland- Including the cities of Osage, Cresco, Waukon, Oelwein, Richland Center, Prairie Du Chien, Decorah, New Hampton, Elkader, and Charles City 136 PM CDT Sat Aug 28 2021 ...FLASH FLOOD WATCH IS CANCELLED... The Flash Flood Watch for portions of Iowa and southwest Wisconsin, including the following areas, in Iowa, Allamakee, Chickasaw, Clayton, Fayette, Floyd, Howard, Mitchell and Winneshiek. In southwest Wisconsin, Crawford and Richland has been cancelled. The Flood Watch is cancelled. Flooding is no longer expected to pose a threat. Please continue to heed remaining road closures. $$ Shea
The 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, 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 27, 11:12 PM CDT | Flash Flood Warning | ARX | Chickasaw, Floyd | 6 hr |
| 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 |
| Aug 27, 7:14 PM CDT | Special Weather Statement | ARX | Olmsted, Wabasha | 31 min |
| Aug 28, 12:11 PM CDT | Special Weather Statement | ARX | Dodge, Fillmore, Houston, Mower, Olmsted, Wabasha and 1 more | 64 min |
| Aug 27, 8:48 PM CDT | Severe Thunderstorm Warning | ARX | Grant | 42 min |
| Aug 27, 8:59 PM CDT | Tornado Warning | ARX | Grant | 31 min |
| Aug 27, 11:24 PM CDT | Special Weather Statement | ARX | Vernon | 36 min |
| Aug 27, 11:31 PM CDT | Severe Thunderstorm Warning | ARX | Richland, Vernon | 59 min |
| Aug 27, 11:41 PM CDT | Flash Flood Warning | ARX | Vernon | 4 hr |
| Aug 27, 11:53 PM CDT | Severe Thunderstorm Warning | ARX | Richland | 37 min |
| Aug 28, 1:40 AM CDT | Severe Thunderstorm Warning | ARX | Crawford, Richland | 49 min |
| Aug 28, 3:15 AM CDT | River Flood Warning | ARX | La Crosse, Trempealeau | 5 days |
| Aug 28, 4:14 AM CDT | River Flood Warning | ARX | Vernon | 31 hr |
| Aug 28, 10:24 AM CDT | River Flood Warning | ARX | Crawford | 4 days |
| Aug 28, 10:38 AM CDT | River Flood Watch | ARX | Juneau | 22 hr |
| Aug 28, 10:46 AM CDT | River Flood Watch | ARX | Crawford | 23 hr |
Nearby
Flash Flood Watches in Iowa, 2021Flash Flood Watches in Minnesota, 2021Flash Flood Watches in Wisconsin, 2021Every flash flood watch 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.