Alert archive / Wisconsin / Flash Flood Watches in 2021

Flash Flood Watch 1, NWS Green Bay, WI

August 7, 202112 counties in Wisconsin

NWS Green Bay, WI issued this flash flood watch at Aug 7, 2021, 6:56 PM CDT for 12 counties in Wisconsin. It was in force for 25 hr.

The area

The counties it named.

The facts

Issued
Aug 7, 2021, 6:56 PM CDT (23:56 UTC)
Expired
Aug 8, 2021, 7:56 PM CDT
In force
25 hr
Issued by
NWS Green Bay, WI
Flood severity
None

Counties Brown County, WI, Calumet County, WI, Kewaunee County, WI, Manitowoc County, WI, Marathon County, WI, Outagamie County, WI, Portage County, WI, Shawano County, WI, Waupaca County, WI, Waushara County, WI, Winnebago County, WI, Wood County, WI

The radar

The Green Bay radar (KGRB), 51 km from the middle of the area, began a volume at 23:55 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, 11.9 hours before the alert went out and 51 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.

994 
WGUS63 KGRB 072356
FFAGRB

URGENT - IMMEDIATE BROADCAST REQUESTED
Flood Watch
National Weather Service Green Bay WI
656 PM CDT Sat Aug 7 2021

WIZ030-035>038-045-048-080800-
/O.NEW.KGRB.FF.A.0001.210807T2356Z-210808T1200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Marathon-Wood-Portage-Waupaca-Outagamie-Waushara-Winnebago-
Including the cities of New London, Redgranite, Plover,
Marshfield, Menasha, Neenah, Wausau, Wisconsin Rapids, Stevens
Point, Wautoma, Appleton, Clintonville, Oshkosh, and Waupaca
656 PM CDT Sat Aug 7 2021

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

The National Weather Service in Green Bay has issued a

* Flash Flood Watch for Portions of central, east central, and 
  northeast Wisconsin, including the following areas, in central 
  Wisconsin, Marathon, Portage, Waushara and Wood. In east central 
  Wisconsin, Winnebago. In northeast Wisconsin, Outagamie and 
  Waupaca.

* Through Sunday morning.

* Rounds of thunderstorms, some producing very heavy rainfall, are 
  expected tonight. Rainfall amounts of 2 to 4 inches, with locally 
  higher amounts possible. This will lead to the possibility of 
  flash flooding.

* Flash flooding of creeks, streams, urban areas, and low lying 
  areas is possible.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

$$

Cooley
5 follow-up statements
841 
WGUS63 KGRB 080443
FFAGRB

Flood Watch
National Weather Service Green Bay WI
1143 PM CDT Sat Aug 7 2021

WIZ030-037-038-080545-
/O.CAN.KGRB.FF.A.0001.000000T0000Z-210808T1200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Marathon-Waupaca-Outagamie-
Including the cities of Wausau, New London, Appleton,
Clintonville, and Waupaca
1143 PM CDT Sat Aug 7 2021

...FLASH FLOOD WATCH IS CANCELLED...

The Flash Flood Watch for Portions of central and northeast 
Wisconsin, including the following areas, in central Wisconsin, 
Marathon. In northeast Wisconsin, Outagamie and Waupaca. has been 
cancelled.

The Flood Watch is cancelled.

$$

WIZ035-036-045-048-081200-
/O.CON.KGRB.FF.A.0001.000000T0000Z-210808T1200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Wood-Portage-Waushara-Winnebago-
Including the cities of Plover, Marshfield, Menasha, Neenah,
Wisconsin Rapids, Stevens Point, Wautoma, Redgranite, and Oshkosh
1143 PM CDT Sat Aug 7 2021

...FLASH FLOOD WATCH REMAINS IN EFFECT UNTIL 7 AM CDT SUNDAY...

The Flash Flood Watch continues for

* Portions of central and east central Wisconsin, including the 
  following areas, in central Wisconsin, Portage, Waushara and Wood. 
  In east central Wisconsin, Winnebago.

* Until 7 AM CDT Sunday.

* Additional rounds of showers and thunderstorms, some producing 
  very heavy rainfall, are expected through early Sunday morning. 
  Additional rainfall amounts up to 1 inch will be possible before 
  the precipitation diminishes. This will lead to the possibility of 
  flash flooding, especially where heavy rainfall occurred Saturday 
  evening.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

$$

Cooley
012 
WGUS63 KGRB 080836
FFAGRB

URGENT - IMMEDIATE BROADCAST REQUESTED
Flood Watch
National Weather Service Green Bay WI
336 AM CDT Sun Aug 8 2021

WIZ030-031-037>039-049-081645-
/O.EXB.KGRB.FF.A.0001.000000T0000Z-210809T0600Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Marathon-Shawano-Waupaca-Outagamie-Brown-Calumet-
Including the cities of Green Bay, Brillion, New London, Wausau,
Shawano, Chilton, New Holstein, Waupaca, Clintonville, and
Appleton
336 AM CDT Sun Aug 8 2021

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

The National Weather Service in Green Bay has expanded the

* Flash Flood Watch to include Portions of central, east central, 
  and northeast Wisconsin, including the following areas, in central 
  Wisconsin, Marathon. In east central Wisconsin, Calumet. In 
  northeast Wisconsin, Brown, Outagamie, Shawano and Waupaca.

* Through late tonight.

* Heavy rains from last night have made for wet ground and rising 
  rivers and streams. Additional heavy rain from thunderstorms is 
  expected, especially during the afternoon and evening hours, which 
  may cause flooding of urban areas, small streams and basements.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

You should monitor later forecasts and be prepared to take action 
should Flash Flood Warnings be issued. Make sure your sump pump is 
working, and be ready to move to higher ground if a warning is 
issued. Do not drive on flooded roadways.

&&

$$

WIZ035-036-045-048-081645-
/O.EXT.KGRB.FF.A.0001.000000T0000Z-210809T0600Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Wood-Portage-Waushara-Winnebago-
Including the cities of Plover, Marshfield, Menasha, Neenah,
Wisconsin Rapids, Stevens Point, Wautoma, Redgranite, and Oshkosh
336 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 central and east central Wisconsin, including the 
  following areas, in central Wisconsin, Portage, Waushara and Wood. 
  In east central Wisconsin, Winnebago.

* Through late tonight.

* Heavy rains from last night has made for wet ground and rising 
  rivers and streams. Thunderstorms will bring additional heavy 
  rain, especially  this afternoon and tonight, which may produce 
  flooding of urban areas, small streams and basements.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

You should monitor later forecasts and be prepared to take action 
should Flash Flood Warnings be issued. Make sure your sump pump 
works, and be ready to move to high ground if a flood warning is 
issued. Do not drive on flooded roadways.

&&

$$

RDM
936 
WGUS63 KGRB 081551
FFAGRB

URGENT - IMMEDIATE BROADCAST REQUESTED
Flood Watch
National Weather Service Green Bay WI
1051 AM CDT Sun Aug 8 2021

WIZ040-050-090000-
/O.EXA.KGRB.FF.A.0001.000000T0000Z-210809T0600Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Kewaunee-Manitowoc-
Including the cities of Two Rivers, Manitowoc, Luxemburg, and
Kewaunee
1051 AM CDT Sun Aug 8 2021

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

The National Weather Service in Green Bay has expanded the

* Flash Flood Watch to include Portions of east central and 
  northeast Wisconsin, including the following areas, in east 
  central Wisconsin, Manitowoc. In northeast Wisconsin, Kewaunee.

* Through late tonight.

* Heavy rains from last night has made for wet ground and rising 
  rivers and streams. Thunderstorms will bring additional heavy 
  rain, especially  this afternoon and tonight, which may produce 
  flooding of urban areas, small streams and basements. The best 
  potential for additional heavy rainfall is between 3PM and 10PM 
  central time.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

$$

WIZ030-031-035>039-045-048-049-090000-
/O.CON.KGRB.FF.A.0001.000000T0000Z-210809T0600Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Marathon-Shawano-Wood-Portage-Waupaca-Outagamie-Brown-Waushara-
Winnebago-Calumet-
Including the cities of Green Bay, Brillion, New London,
Redgranite, Plover, Marshfield, Menasha, Neenah, Wausau,
Wisconsin Rapids, Stevens Point, Shawano, Chilton, New Holstein,
Wautoma, Appleton, Clintonville, Oshkosh, and Waupaca
1051 AM CDT Sun Aug 8 2021

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

The Flash Flood Watch continues for

* Portions of central, east central, and northeast Wisconsin, 
  including the following areas, in central Wisconsin, Marathon, 
  Portage, Waushara and Wood. In east central Wisconsin, Calumet and 
  Winnebago. In northeast Wisconsin, Brown, Outagamie, Shawano and 
  Waupaca.

* Through late tonight.

* Heavy rains from last night has made for wet ground and rising 
  rivers and streams. Thunderstorms will bring additional heavy 
  rain, especially  this afternoon and tonight, which may produce 
  flooding of urban areas, small streams and basements.  The best 
  potential for additional heavy rainfall is between 3PM and 10PM 
  central time.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

$$

Uhlmann
510 
WGUS63 KGRB 082027
FFAGRB

Flood Watch
National Weather Service Green Bay WI
327 PM CDT Sun Aug 8 2021

WIZ030-031-035>040-045-048>050-090430-
/O.CON.KGRB.FF.A.0001.000000T0000Z-210809T0600Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Marathon-Shawano-Wood-Portage-Waupaca-Outagamie-Brown-Kewaunee-
Waushara-Winnebago-Calumet-Manitowoc-
Including the cities of Brillion, New London, Clintonville,
Oshkosh, Appleton, Marshfield, Neenah, Wausau, Manitowoc,
Chilton, Luxemburg, Waupaca, Green Bay, Redgranite, Plover,
Menasha, Two Rivers, Wisconsin Rapids, Stevens Point, Shawano,
New Holstein, Wautoma, and Kewaunee
327 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, east central, and northeast Wisconsin, 
  including the following areas, in central Wisconsin, Marathon, 
  Portage, Waushara and Wood. In east central Wisconsin, Calumet, 
  Manitowoc and Winnebago. In northeast Wisconsin, Brown, Kewaunee, 
  Outagamie, Shawano and Waupaca.

* Until 1 AM CDT Monday.

* Thunderstorms will overspread central to east-central Wisconsin 
  this afternoon and evening, with the heaviest rainfall potential 
  lasting through around 10 PM. Another inch is possible in many of 
  the areas that received heavy rainfall last night, with locally 
  higher amounts under the strongest storms. The additional rainfall 
  is expected to pose an urban and small stream flash flooding 
  concern.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

$$

Uhlmann
324 
WGUS63 KGRB 090056
FFAGRB

Flood Watch
National Weather Service Green Bay WI
756 PM CDT Sun Aug 8 2021

WIZ030-031-035>040-045-048>050-090200-
/O.CAN.KGRB.FF.A.0001.000000T0000Z-210809T0600Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Marathon-Shawano-Wood-Portage-Waupaca-Outagamie-Brown-Kewaunee-
Waushara-Winnebago-Calumet-Manitowoc-
Including the cities of Brillion, New London, Clintonville,
Oshkosh, Appleton, Marshfield, Neenah, Wausau, Manitowoc,
Chilton, Luxemburg, Waupaca, Green Bay, Redgranite, Plover,
Menasha, Two Rivers, Wisconsin Rapids, Stevens Point, Shawano,
New Holstein, Wautoma, and Kewaunee
756 PM CDT Sun Aug 8 2021

...FLASH FLOOD WATCH IS CANCELLED...

The Flash Flood Watch for Portions of central, east central, and 
northeast Wisconsin, including the following areas, in central 
Wisconsin, Marathon, Portage, Waushara and Wood. In east central 
Wisconsin, Calumet, Manitowoc and Winnebago. In northeast Wisconsin, 
Brown, Kewaunee, Outagamie, Shawano and Waupaca. has been cancelled.

The Flood Watch is cancelled. Flooding is no longer expected to pose 
a threat. Please continue to heed remaining road closures.

$$

Cooley

Nearby

Flash 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.