Alert archive / Wisconsin / Flash Flood Watches in 2021

Flash Flood Watch 1, NWS La Crosse, WI

August 7, 2021Allamakee County, Winneshiek County, Iowa; 11 counties in Wisconsin; 5 counties in Minnesota

NWS La Crosse, WI issued this flash flood watch at Aug 7, 2021, 6:18 PM CDT for Allamakee County, Winneshiek County, Iowa; 11 counties in Wisconsin; 5 counties in Minnesota. It was in force for 35 hr.

The area

The counties it named.

The facts

Issued
Aug 7, 2021, 6:18 PM CDT (23:18 UTC)
Expired
Aug 9, 2021, 5:11 AM CDT
In force
35 hr
Issued by
NWS La Crosse, WI
Flood severity
None

Counties Allamakee County, IA, Winneshiek County, IA, Fillmore County, MN, Houston County, MN, Olmsted County, MN, Wabasha County, MN, Winona County, MN, Adams County, WI, Buffalo County, WI, Clark County, WI, Crawford County, WI, Jackson County, WI, Juneau County, WI, La Crosse County, WI, Monroe County, WI, Richland County, WI, Trempealeau County, WI, Vernon County, WI

The radar

The La Crosse radar (KARX), 7 km from the middle of the area, began a volume at 23:16 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

Green Bay/Straub, WI (KGRB), launched 12:00Z, 11.3 hours before the alert went out and 256 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, Green Bay/Straub, WI at 12:00Z on 2021-08-07Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 20 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, Green Bay/Straub, WI at 12:00Z on 2021-08-07The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 72 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
20 J/kg
Mixed-layer CIN
-32 J/kg
Mixed-layer LCL
656 m above ground
0-6 km bulk shear
17 kt
0-1 km storm-relative helicity
72 m²/s²
0-3 km storm-relative helicity
103 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

331 
WGUS63 KARX 072318
FFAARX

URGENT - IMMEDIATE BROADCAST REQUESTED
Flood Watch
National Weather Service La Crosse WI
618 PM CDT Sat Aug 7 2021

.A storm system to our west will move in overnight with additional 
rounds of thunderstorms.  Heavy rainfall of 1 to 3 inches of 
rainfall fell over a large area over southeast Minnesota, western 
and north central Wisconsin, and parts of northeast Iowa with 
pockets of 3 to 7 inches of rainfall especially along the I90 and 
I94 corridors and into west central Wisconsin.  Thunderstorms are 
expected to re-develop tonight in an east-west line, affecting some 
of the same locations that received heavy rainfall Saturday.

IAZ010-011-MNZ079-087-088-095-096-WIZ029-032>034-041>044-053>055-
080730-
/O.NEW.KARX.FF.A.0001.210807T2318Z-210808T1500Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Winneshiek-Allamakee-Wabasha-Olmsted-Winona-Fillmore-Houston-Clark-
Buffalo-Trempealeau-Jackson-La Crosse-Monroe-Juneau-Adams-Vernon-
Crawford-Richland-
Including the cities of Arcadia, Richland Center, Rochester, Waukon, 
Neillsville, Whitehall, Friendship, Preston, Sparta, Prairie Du 
Chien, Viroqua, La Crosse, Winona, Decorah, Black River Falls, 
Tomah, Caledonia, Wabasha, Mauston, and Alma
618 PM CDT Sat Aug 7 2021

...FLASH FLOOD WATCH IN EFFECT THROUGH SUNDAY MORNING...

The National Weather Service in La Crosse has issued a

* Flash Flood Watch for portions of northeast Iowa, southeast 
  Minnesota and Wisconsin, including the following areas, in 
  northeast Iowa, Allamakee and Winneshiek. In southeast Minnesota, 
  Fillmore, Houston, Olmsted, Wabasha and Winona. In Wisconsin, 
  Adams, Buffalo, Clark, Crawford, Jackson, Juneau, La Crosse, 
  Monroe, Richland, Trempealeau and Vernon.

* Through Sunday morning.

* Heavy rainfall of 1 to 3 inches of rainfall fell over a large area 
  over southeast Minnesota, western and north central Wisconsin, and 
  parts of northeast Iowa with pockets of 3 to 7 inches of rainfall 
  especially along the I90 and I94 corridors and into west central 
  Wisconsin.  Thunderstorms are expected to re-develop tonight in an 
  east-west line, affecting some of the same locations that received 
  heavy rainfall Saturday.  1 to 4 inches of additional rainfall may 
  fall over parts of the flash flood watch area.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

You should monitor later forecasts and be prepared to take action 
should Flash Flood Warnings be issued.

&&

$$

CZ
6 follow-up statements
288 
WGUS63 KARX 080405
FFAARX

Flood Watch
National Weather Service La Crosse WI
1105 PM CDT Sat Aug 7 2021

.Saturday evening, a warm front remained draped from near Rochester 
toward Preston to near Boscobel and Lone Rock.  Storms are expected 
to re-develop overnight as a storm system moves in from the west.  
The storm system will tap a moist and unstable atmosphere.  These 
storms will be efficient rain producers.  Due to the heavy rainfall 
potential on already saturated soils, additional rainfall may 
produce flash flooding.

IAZ010-011-MNZ079-087-088-095-096-WIZ029-032>034-041>044-053>055-
081500-
/O.CON.KARX.FF.A.0001.000000T0000Z-210808T1500Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Winneshiek-Allamakee-Wabasha-Olmsted-Winona-Fillmore-Houston-Clark-
Buffalo-Trempealeau-Jackson-La Crosse-Monroe-Juneau-Adams-Vernon-
Crawford-Richland-
Including the cities of Arcadia, Richland Center, Rochester, Waukon, 
Neillsville, Whitehall, Friendship, Preston, Sparta, Prairie Du 
Chien, Viroqua, La Crosse, Winona, Decorah, Black River Falls, 
Tomah, Caledonia, Wabasha, Mauston, and Alma
1105 PM CDT Sat Aug 7 2021

...FLASH FLOOD WATCH REMAINS IN EFFECT UNTIL 10 AM CDT SUNDAY...

The Flash Flood Watch continues for

* Portions of northeast Iowa, southeast Minnesota and Wisconsin, 
  including the following areas, in northeast Iowa, Allamakee and 
  Winneshiek. In southeast Minnesota, Fillmore, Houston, Olmsted, 
  Wabasha and Winona. In Wisconsin, Adams, Buffalo, Clark, Crawford, 
  Jackson, Juneau, La Crosse, Monroe, Richland, Trempealeau and 
  Vernon.

* Until 10 AM CDT Sunday.

* Heavy rainfall from 1 to 7 inches fell over parts of southeast 
  Minnesota, western and north central Wisconsin, and parts of 
  northeast Iowa.  Some locations cannot take much additional rain 
  and heavy rainfall is likely overnight. The storms will be capable 
  of 1 to 2 inch per hour rainfall rates.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

You should monitor later forecasts and be prepared to take action 
should Flash Flood Warnings be issued.

&&

$$

CZ
401 
WGUS63 KARX 080826
FFAARX

URGENT - IMMEDIATE BROADCAST REQUESTED
Flood Watch
National Weather Service La Crosse WI
326 AM CDT Sun Aug 8 2021

IAZ010-011-MNZ079-087-088-095-096-WIZ029-032>034-041>044-053>055-
081630-
/O.EXT.KARX.FF.A.0001.000000T0000Z-210809T0600Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Winneshiek-Allamakee-Wabasha-Olmsted-Winona-Fillmore-Houston-Clark-
Buffalo-Trempealeau-Jackson-La Crosse-Monroe-Juneau-Adams-Vernon-
Crawford-Richland-
Including the cities of Arcadia, Richland Center, Rochester, Waukon, 
Neillsville, Whitehall, Friendship, Preston, Sparta, Prairie Du 
Chien, Viroqua, La Crosse, Winona, Decorah, Black River Falls, 
Tomah, Caledonia, Wabasha, Mauston, and Alma
326 AM CDT Sun Aug 8 2021

...FLASH FLOOD WATCH NOW IN EFFECT THROUGH LATE TONIGHT...

The Flash Flood Watch is now in effect for

* Portions of northeast Iowa, southeast Minnesota and Wisconsin, 
  including the following areas, in northeast Iowa, Allamakee and 
  Winneshiek. In southeast Minnesota, Fillmore, Houston, Olmsted, 
  Wabasha and Winona. In Wisconsin, Adams, Buffalo, Clark, Crawford, 
  Jackson, Juneau, La Crosse, Monroe, Richland, Trempealeau and 
  Vernon.

* Through late tonight.

* Heavy rainfall over the past 24 hours has resulted in saturated 
  soils. Additional rounds of rain are expected into tonight, with 
  high rainfall rates of 1 to 2 inches per hour possible with any 
  storms. The rainfall could quickly result in flash flooding in 
  these areas.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

You should monitor later forecasts and be prepared to take action 
should Flash Flood Warnings be issued.

&&

$$

JAM
370 
WGUS63 KARX 081507
FFAARX

Flood Watch
National Weather Service La Crosse WI
1007 AM CDT Sun Aug 8 2021

IAZ010-011-MNZ079-087-088-095-096-081615-
/O.CAN.KARX.FF.A.0001.000000T0000Z-210809T0600Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Winneshiek-Allamakee-Wabasha-Olmsted-Winona-Fillmore-Houston-
Including the cities of Rochester, Waukon, Preston, Winona, Decorah, 
Caledonia, and Wabasha
1007 AM CDT Sun Aug 8 2021

...FLASH FLOOD WATCH IS CANCELLED...

The Flash Flood Watch for portions of northeast Iowa and southeast 
Minnesota, including the following areas, in northeast Iowa, 
Allamakee and Winneshiek. In southeast Minnesota, Fillmore, Houston, 
Olmsted, Wabasha and Winona has been cancelled.

The Flood Watch is cancelled. At this time, it looks like any 
additional storms with heavy rain will primarily be east of the 
Mississippi River later today.

$$

WIZ029-032>034-041>044-053>055-082315-
/O.CON.KARX.FF.A.0001.000000T0000Z-210809T0600Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Clark-Buffalo-Trempealeau-Jackson-La Crosse-Monroe-Juneau-Adams-
Vernon-Crawford-Richland-
Including the cities of Arcadia, Richland Center, Black River Falls, 
Alma, Neillsville, Whitehall, Prairie Du Chien, Sparta, Viroqua, La 
Crosse, Tomah, Friendship, and Mauston
1007 AM CDT Sun Aug 8 2021

...FLASH FLOOD WATCH REMAINS IN EFFECT THROUGH LATE TONIGHT...

The Flash Flood Watch continues for

* Portions of central Wisconsin, southwest Wisconsin and west 
  central Wisconsin, including the following areas, in central 
  Wisconsin, Adams, Clark and Juneau. In southwest Wisconsin, 
  Crawford, Richland and Vernon. In west central Wisconsin, Buffalo, 
  Jackson, La Crosse, Monroe and Trempealeau.

* Through late tonight.

* Heavy rainfall Saturday afternoon and evening resulted in 
  saturated soils. Additional storms with heavy rain will be 
  possible this afternoon into the evening, with rainfall rates of 1 
  to 2 inches per hour possible. This rainfall could quickly result 
  in flash floodig.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

You should monitor later forecasts and be prepared to take action 
should Flash Flood Warnings be issued.

&&

$$

04
711 
WGUS63 KARX 082358
FFAARX

Flood Watch
National Weather Service La Crosse WI
658 PM CDT Sun Aug 8 2021

WIZ029-032>034-041>044-053>055-090600-
/O.CON.KARX.FF.A.0001.000000T0000Z-210809T0600Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Clark-Buffalo-Trempealeau-Jackson-La Crosse-Monroe-Juneau-Adams-
Vernon-Crawford-Richland-
Including the cities of Neillsville, Alma, Arcadia, Whitehall, 
Black River Falls, La Crosse, Sparta, Tomah, Mauston, Friendship,
Viroqua, Prairie Du Chien, and Richland Center
658 PM CDT Sun Aug 8 2021

...FLASH FLOOD WATCH REMAINS IN EFFECT UNTIL 1 AM CDT MONDAY...

The Flash Flood Watch continues for

* Portions of central Wisconsin, southwest Wisconsin, and west 
  central Wisconsin, including the following areas, in central 
  Wisconsin, Adams, Clark, and Juneau. In southwest Wisconsin, 
  Crawford, Richland, and Vernon. In west central Wisconsin, 
  Buffalo, Jackson, La Crosse, Monroe, and Trempealeau. 

* Until 1 AM CDT Monday

* Heavy rainfall Saturday afternoon and evening resulted in
  saturated soils. Additional storms with heavy rain will be
  possible into the evening, with rainfall rates of 1 to 2 inches
  per hour possible and would mostly run off.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

You should monitor later forecasts and be prepared to take action
should Flash Flood Warnings be issued.

&&

$$

Zapotocny
803 
WGUS63 KARX 090436
FFAARX

URGENT - IMMEDIATE BROADCAST REQUESTED
Flood Watch
National Weather Service La Crosse WI
1136 PM CDT Sun Aug 8 2021

WIZ029-032>034-041>044-053>055-091200-
/O.EXT.KARX.FF.A.0001.000000T0000Z-210809T1200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Clark-Buffalo-Trempealeau-Jackson-La Crosse-Monroe-Juneau-Adams-
Vernon-Crawford-Richland-
Including the cities of Neillsville, Alma, Arcadia, Whitehall, 
Black River Falls, La Crosse, Sparta, Tomah, Mauston, Friendship,
Viroqua, Prairie Du Chien, and Richland Center
1136 PM CDT Sun Aug 8 2021

...FLASH FLOOD WATCH NOW IN EFFECT UNTIL 7 AM CDT MONDAY...

The Flash Flood Watch is now in effect for

* Portions of central Wisconsin, southwest Wisconsin, and west 
  central Wisconsin, including the following areas, in central 
  Wisconsin, Adams, Clark, and Juneau. In southwest Wisconsin, 
  Crawford, Richland, and Vernon. In west central Wisconsin, 
  Buffalo, Jackson, La Crosse, Monroe, and Trempealeau. 

* Until 7 AM CDT Monday

* Heavy rainfall Saturday and Sunday resulted in saturated soils.
  Pockets of locally heavy rainfall with rainfall rates of 1 to 2
  inches per hour will continue tonight with flash flooding
  possible. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

You should monitor later forecasts and be prepared to take action
should Flash Flood Warnings be issued.

&&

$$

Zapotocny
411 
WGUS63 KARX 091011
FFAARX

Flood Watch
National Weather Service La Crosse WI
511 AM CDT Mon Aug 9 2021

WIZ029-032>034-041>044-053>055-091115-
/O.CAN.KARX.FF.A.0001.000000T0000Z-210809T1200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Clark-Buffalo-Trempealeau-Jackson-La Crosse-Monroe-Juneau-Adams-
Vernon-Crawford-Richland-
Including the cities of Arcadia, Richland Center, Black River Falls, 
Alma, Neillsville, Whitehall, Prairie Du Chien, Sparta, Viroqua, La 
Crosse, Tomah, Friendship, and Mauston
511 AM CDT Mon Aug 9 2021

...FLASH FLOOD WATCH IS CANCELLED...

The Flash Flood Watch for portions of central Wisconsin, southwest 
Wisconsin and west central Wisconsin, including the following areas, 
in central Wisconsin, Adams, Clark and Juneau. In southwest 
Wisconsin, Crawford, Richland and Vernon. In west central Wisconsin, 
Buffalo, Jackson, La Crosse, Monroe and Trempealeau has been 
cancelled.

The Flood Watch is cancelled. Although showers and storms will 
continue for a few more hours, the likelihood of flooding is 
decreasing. Please continue to heed remaining road closures.

$$

JAM

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 7, 6:26 AM CDTSpecial Weather StatementARXBuffalo34 min
Aug 7, 7:40 AM CDTSpecial Weather StatementARXLa Crosse35 min
Aug 7, 9:17 AM CDTSpecial Weather StatementARXJuneau28 min
Aug 7, 10:12 AM CDTSpecial Weather StatementARXAdams33 min
Aug 7, 11:17 AM CDTSpecial Weather StatementARXCrawford28 min
Aug 7, 11:24 AM CDTSevere Thunderstorm WarningARXLa Crosse, Vernon27 min
Aug 7, 11:26 AM CDTSevere Thunderstorm WarningARXCrawford, Richland, Vernon21 min
Aug 7, 12:19 PM CDTSpecial Weather StatementARXRichland26 min
Aug 7, 12:59 PM CDTAreal Flood AdvisoryARXBuffalo2 hr
Aug 7, 1:17 PM CDTSevere Thunderstorm WarningARXRichland, Vernon58 min
Aug 7, 1:48 PM CDTSpecial Weather StatementARXLa Crosse27 min
Aug 7, 2:14 PM CDTSpecial Weather StatementARXLa Crosse31 min
Aug 7, 2:23 PM CDTAreal Flood AdvisoryARXLa Crosse, Trempealeau112 min
Aug 7, 3:02 PM CDTRiver Flood WarningARXMonroe, Vernon21 days
Aug 7, 3:02 PM CDTRiver Flood WarningARXVernon4 days
Aug 7, 3:02 PM CDTRiver Flood WarningARXRichland, Vernon4 days
Aug 7, 3:02 PM CDTRiver Flood WarningARXRichland, Vernon61 hr
Aug 7, 3:02 PM CDTRiver Flood WarningARXBuffalo, Trempealeau19 hr
Aug 7, 3:07 PM CDTAreal Flood AdvisoryARXLa Crosse74 min
Aug 7, 3:17 PM CDTSpecial Weather StatementARXVernon73 min
Aug 7, 3:23 PM CDTFlash Flood WarningARXLa Crosse, Monroe3 hr
Aug 7, 3:35 PM CDTSevere Thunderstorm WarningARXVernon55 min
Aug 7, 3:52 PM CDTSevere Thunderstorm WarningARXCrawford38 min
Aug 7, 4:00 PM CDTTornado WarningARXCrawford30 min
Aug 7, 4:05 PM CDTSevere Thunderstorm WarningARXRichland40 min
Aug 7, 4:19 PM CDTTornado WarningARXCrawford, Grant41 min
Aug 7, 4:27 PM CDTFlash Flood WarningARXVernon3 hr
Aug 7, 4:56 PM CDTTornado Warning Tornado observedARXGrant19 min
Aug 7, 5:53 PM CDTSevere Thunderstorm WarningARXJuneau, Monroe, Vernon37 min
Aug 7, 7:21 AM CDTSpecial Weather StatementARXWinona24 min
Aug 7, 10:29 AM CDTSpecial Weather StatementARXOlmsted31 min
Aug 7, 10:33 AM CDTSevere Thunderstorm WarningARXDodge, Olmsted, Wabasha42 min
Aug 7, 11:14 AM CDTSpecial Weather StatementARXWabasha31 min
Aug 7, 12:12 PM CDTSpecial Weather StatementARXWabasha18 min
Aug 7, 12:23 PM CDTSpecial Weather StatementARXOlmsted37 min

Nearby

Flash Flood Watches in Wisconsin, 2021Flash Flood Watches in Minnesota, 2021Flash Flood Watches in Iowa, 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.