Alert archive / Wisconsin / Flash Flood Warnings in 2021

Flash Flood Warning 10, NWS Green Bay, WI

August 28, 2021Portage County, Waupaca County, Wisconsin

NWS Green Bay, WI issued this flash flood warning at Aug 28, 2021, 11:22 PM CDT for Portage County, Waupaca County, Wisconsin. It was in force for 3 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 28, 2021, 11:22 PM CDT (04:22 UTC)
Expired: Aug 29, 2021, 2:30 AM CDT
In force: 3 hr
Issued by: NWS Green Bay, WI
Area: Storm-based polygon
Flood severity: None

Counties Portage County, WI, Waupaca County, WI

The radar

The Green Bay radar (KGRB), 98 km from the middle of the area, began a volume at 04:26 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 29, 12:31 AM CDT	FLOOD	5 W New London, WI	2 INCHES OF WATER CROSSING HIGHWAY X NEAR LOSS ROAD.
Aug 29, 1:30 AM CDT	FLOOD	Weyauwega, WI	WATER ON HIGHWAY AA IN WEYAUWEGA.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Green Bay/Straub, WI (KGRB), launched 00:00Z, 4.4 hours before the alert went out and 98 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 969 J/kg
Mixed-layer CIN: -84 J/kg
Mixed-layer LCL: 1292 m above ground
0-6 km bulk shear: 30 kt
0-1 km storm-relative helicity: 70 m²/s²
0-3 km storm-relative helicity: 110 m²/s²
Significant tornado parameter: 0.1
Supercell composite: 2.0

Open this sounding in Storm Lab

The text

As transmitted.

403 
WGUS53 KGRB 290422
FFWGRB
WIC097-135-290730-
/O.NEW.KGRB.FF.W.0010.210829T0422Z-210829T0730Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Green Bay WI
1122 PM CDT Sat Aug 28 2021

The National Weather Service in Green Bay has issued a

* Flash Flood Warning for...
  Southern Portage County in central Wisconsin...
  Waupaca County in northeastern Wisconsin...

* Until 230 AM CDT.

* At 1122 PM CDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 1 and 2 inches of rain 
  have fallen. The expected rainfall rate is 3 inches in 1 hour. 
  Additional rainfall amounts of 1 to 2 inches are possible in the 
  warned area. Flash flooding is ongoing or expected to begin 
  shortly.

  HAZARD...Flash flooding caused by thunderstorms.

  SOURCE...Radar.

  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...
  Waupaca, New London, Whiting, Amherst, Fremont, Hartman Creek 
  State Park, Chain O' Lakes-King, Lake Wazeecha, Plover, Weyauwega, 
  Royalton, Manawa, Iola, King, Biron, Sheridan, Almond, Amherst 
  Junction, Scandinavia and Blaine.

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 4448 8973 4455 8874 4424 8874 4425 8972

FLASH FLOOD...RADAR INDICATED
EXPECTED RAINFALL...3 INCHES IN 1 HOUR

$$

Kurimski

3 follow-up statements

215 
WGUS73 KGRB 290551
FFSGRB

Flash Flood Statement
National Weather Service Green Bay WI
1251 AM CDT Sun Aug 29 2021

WIC097-290601-
/O.CAN.KGRB.FF.W.0010.000000T0000Z-210829T0730Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Portage WI-
1251 AM CDT Sun Aug 29 2021

...FLASH FLOOD WARNING IS CANCELLED FOR SOUTHERN PORTAGE COUNTY...

Doppler radar indicated that the heavy rain has ended across Portage 
County and flooding is no longer expected to pose a threat. Please 
continue to heed remaining road closures.

LAT...LON 4452 8922 4455 8874 4424 8874 4424 8878
      4424 8883 4424 8889 4424 8896 4424 8903
      4424 8922 4434 8922 4437 8922 4438 8922
      4442 8922 4443 8922 4449 8922

$$

WIC135-290730-
/O.CON.KGRB.FF.W.0010.000000T0000Z-210829T0730Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Waupaca WI-
1251 AM CDT Sun Aug 29 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 230 AM CDT EARLY THIS 
MORNING FOR WAUPACA COUNTY...

At 1251 AM CDT, Doppler radar indicated thunderstorms producing 
heavy rain across the warned area. Between 1 and 2 inches of rain 
have fallen. The expected rainfall rate is 3 inches in 1 hour. 
Additional rainfall amounts of 1 to 2 inches are possible in the 
warned area. Flash flooding is ongoing or expected to begin shortly.

HAZARD...Flash flooding caused by thunderstorms.

SOURCE...Radar.

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...
  Waupaca, New London, Fremont, Chain O' Lakes-King, Hartman Creek 
  State Park, Weyauwega, Royalton, Manawa, Iola, King, Sheridan, 
  Scandinavia, Ogdensburg, Lind Center, Symco, Northport, Fitzgerald 
  Corners, Rural and Readfield.

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 4452 8922 4455 8874 4424 8874 4424 8878
      4424 8883 4424 8889 4424 8896 4424 8903
      4424 8922 4434 8922 4437 8922 4438 8922
      4442 8922 4443 8922 4449 8922

FLASH FLOOD...RADAR INDICATED
EXPECTED RAINFALL...3 INCHES IN 1 HOUR

$$

Kurimski

543 
WGUS73 KGRB 290705
FFSGRB

Flash Flood Statement
National Weather Service Green Bay WI
205 AM CDT Sun Aug 29 2021

WIC135-290730-
/O.CON.KGRB.FF.W.0010.000000T0000Z-210829T0730Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Waupaca WI-
205 AM CDT Sun Aug 29 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 230 AM CDT EARLY THIS 
MORNING FOR WAUPACA COUNTY...

At 205 AM CDT, Doppler radar indicated between 2 and 3 inches of 
rain has fallen across Waupaca County. Although the heavy rain has 
ended, there could still be flash flooding across portions of the 
county. Local law enforcement indicated the Wolf River has been 
rising and could produce flooding.

HAZARD...Flash flooding caused by thunderstorms.

SOURCE...Radar.

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...
  Waupaca, New London, Fremont, Chain O' Lakes-King, Hartman Creek 
  State Park, Weyauwega, Royalton, Manawa, Iola, King, Sheridan, 
  Scandinavia, Ogdensburg, Lind Center, Symco, Northport, Fitzgerald 
  Corners, Rural and Readfield.

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 4452 8922 4455 8874 4424 8874 4424 8878
      4424 8883 4424 8889 4424 8896 4424 8903
      4424 8922 4434 8922 4437 8922 4438 8922
      4442 8922 4443 8922 4449 8922

FLASH FLOOD...RADAR INDICATED

$$

Kurimski

559 
WGUS73 KGRB 290727
FFSGRB

Flash Flood Statement
National Weather Service Green Bay WI
227 AM CDT Sun Aug 29 2021

WIC135-290737-
/O.EXP.KGRB.FF.W.0010.000000T0000Z-210829T0730Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Waupaca WI-
227 AM CDT Sun Aug 29 2021

...FLASH FLOOD WARNING WILL EXPIRE AT 230 AM CDT EARLY THIS MORNING 
FOR WAUPACA COUNTY...

The heavy rain has ended. Flooding is no longer expected to pose a 
threat. Please continue to heed remaining road closures.

LAT...LON 4452 8922 4455 8874 4424 8874 4424 8878
      4424 8883 4424 8889 4424 8896 4424 8903
      4424 8922 4434 8922 4437 8922 4438 8922
      4442 8922 4443 8922 4449 8922

$$

Kurimski

The office that day

Everything else NWS Green Bay, WI issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Aug 28, 8:48 PM CDT	Special Weather Statement	GRB	Florence	42 min
Aug 28, 9:02 PM CDT	Special Weather Statement	GRB	Manitowoc	43 min
Aug 28, 10:06 PM CDT	Areal Flood Advisory	GRB	Calumet, Manitowoc	62 min
Aug 28, 10:24 PM CDT	River Flood Warning	GRB	Wood	21 days
Aug 28, 10:38 PM CDT	Areal Flood Advisory	GRB	Portage, Waupaca, Wood	3 hr
Aug 28, 11:08 PM CDT	Flash Flood Warning	GRB	Calumet, Manitowoc	89 min
Aug 29, 12:08 AM CDT	Areal Flood Advisory	GRB	Outagamie	3 hr
Aug 29, 1:15 AM CDT	Special Marine Warning	GRB		34 min

Nearby

Flash Flood Warnings in Wisconsin, 2021 Every 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.