Alert archive / Wisconsin / Flash Flood Warnings in 2021

Flash Flood Warning 2, NWS Green Bay, WI

July 15, 2021Calumet County, Manitowoc County, Winnebago County, Wisconsin

NWS Green Bay, WI issued this flash flood warning at Jul 15, 2021, 2:00 AM CDT for Calumet County, Manitowoc County, Winnebago County, Wisconsin. It was in force for 4 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
Jul 15, 2021, 2:00 AM CDT (07:00 UTC)
Expired
Jul 15, 2021, 6:00 AM CDT
In force
4 hr
Issued by
NWS Green Bay, WI
Area
Storm-based polygon
Flood severity
None

Counties Calumet County, WI, Manitowoc County, WI, Winnebago County, WI

The radar

The Green Bay radar (KGRB), 55 km from the middle of the area, began a volume at 07:01 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

TimeReportWhereRemark
Jul 15, 2:16 AM CDTHEAVY RAIN 4.312 Nne Oshkosh, WI
Jul 15, 4:00 AM CDTFLASH FLOODManitowoc, WINUMEROUS REPORTS OF FLOODED, IMPASSABLE ROADS IN MANITOWOC AND SURROUNDING AREAS.

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, 7.0 hours before the alert went out and 53 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 00:00Z on 2021-07-15Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 3 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 00:00Z on 2021-07-15The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 83 square meters per square second.19395878Sfc1 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
3 J/kg
Mixed-layer CIN
-195 J/kg
Mixed-layer LCL
1171 m above ground
0-6 km bulk shear
56 kt
0-1 km storm-relative helicity
83 m²/s²
0-3 km storm-relative helicity
207 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

070 
WGUS53 KGRB 150700
FFWGRB
WIC015-071-139-151100-
/O.NEW.KGRB.FF.W.0002.210715T0700Z-210715T1100Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Green Bay WI
200 AM CDT Thu Jul 15 2021

The National Weather Service in Green Bay has issued a

* Flash Flood Warning for...
  Calumet County in east central Wisconsin...
  Manitowoc County in east central Wisconsin...
  Eastern Winnebago County in east central Wisconsin...

* Until 600 AM CDT.

* At 200 AM CDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 2 and 4 inches of rain 
  have fallen. Additional rainfall amounts to 1 inch, locally up 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...
  Oshkosh, Manitowoc, Chilton, Brillion, Cleveland, Valders, St. 
  Nazianz, Two Creeks, Camp Rokilio Scout Camp, St Anna, High Cliff 
  State Park, Two Rivers, Harrison, Kiel, New Holstein, Sherwood, 
  Newton and Cato.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around, don't drown when encountering flooded roads. Most flood 
deaths occur in vehicles.

Be aware of your surroundings and do not drive on flooded roads.

&&

LAT...LON 4389 8864 4412 8856 4433 8749 4418 8745
      4407 8759 4390 8767 4389 8816 4394 8816
      4394 8840 4389 8840

FLASH FLOOD...RADAR INDICATED

$$

MPC
3 follow-up statements
304 
WGUS73 KGRB 150758
FFSGRB

Flash Flood Statement
National Weather Service Green Bay WI
258 AM CDT Thu Jul 15 2021

WIC015-071-139-151100-
/O.CON.KGRB.FF.W.0002.000000T0000Z-210715T1100Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Calumet WI-Manitowoc WI-Winnebago WI-
258 AM CDT Thu Jul 15 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 6 AM CDT EARLY THIS 
MORNING FOR CALUMET, MANITOWOC AND EASTERN WINNEBAGO COUNTIES...

At 258 AM CDT, Doppler radar indicated thunderstorms producing heavy 
rain across the warned area. Between 2 and 5 inches of rain have 
fallen. Additional rainfall amounts up to 1 inch 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...
  Oshkosh, Manitowoc, Chilton, Brillion, Cleveland, Valders, St. 
  Nazianz, Two Creeks, Camp Rokilio Scout Camp, St Anna, High Cliff 
  State Park, Two Rivers, Harrison, Kiel, New Holstein, Sherwood, 
  Newton and Cato.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Be especially cautious at night when it is harder to recognize the 
dangers of flooding.

Please report observed flooding to local emergency services or law 
enforcement and request they pass this information to the National 
Weather Service when you can do so safely.

&&

LAT...LON 4389 8864 4412 8856 4433 8749 4418 8745
      4407 8759 4390 8767 4389 8816 4394 8816
      4394 8840 4389 8840

FLASH FLOOD...RADAR INDICATED

$$

Skowronski
476 
WGUS73 KGRB 150832
FFSGRB

Flash Flood Statement
National Weather Service Green Bay WI
332 AM CDT Thu Jul 15 2021

WIC015-071-139-151100-
/O.CON.KGRB.FF.W.0002.000000T0000Z-210715T1100Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Calumet WI-Manitowoc WI-Winnebago WI-
332 AM CDT Thu Jul 15 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 6 AM CDT EARLY THIS 
MORNING FOR CALUMET, MANITOWOC AND EASTERN WINNEBAGO COUNTIES...

At 332 AM CDT, Doppler radar and automated rain gauges indicated 
that thunderstorms earlier in the night produced heavy rain across 
the warned area. Between 2 and 5 inches of rain were reported. Flash 
flooding is ongoing.

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...
  Oshkosh, Manitowoc, Chilton, Brillion, Cleveland, Valders, St. 
  Nazianz, Two Creeks, Camp Rokilio Scout Camp, St Anna, High Cliff 
  State Park, Two Rivers, Harrison, Kiel, New Holstein, Sherwood, 
  Newton and Cato.

Although the heavy rain was now southeast of the area, scattered 
showers may persist through daybreak. Runoff from the rainfall will 
continue, and it will take a little while for standing water to 
subside.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Be especially cautious at night when it is harder to recognize the 
dangers of flooding.

Please report observed flooding to local emergency services or law 
enforcement and request they pass this information to the National 
Weather Service when you can do so safely.

&&

LAT...LON 4389 8864 4412 8856 4433 8749 4418 8745
      4407 8759 4390 8767 4389 8816 4394 8816
      4394 8840 4389 8840

FLASH FLOOD...RADAR AND GAUGE INDICATED

$$

Skowronski
854 
WGUS73 KGRB 151013
FFSGRB

Flash Flood Statement
National Weather Service Green Bay WI
513 AM CDT Thu Jul 15 2021

WIC015-071-139-151100-
/O.CON.KGRB.FF.W.0002.000000T0000Z-210715T1100Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Calumet WI-Manitowoc WI-Winnebago WI-
513 AM CDT Thu Jul 15 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 6 AM CDT EARLY THIS 
MORNING FOR CALUMET, MANITOWOC AND EASTERN WINNEBAGO COUNTIES...

At 513 AM CDT, Doppler radar and automated rain gauges indicated 
that thunderstorms produced 2 to 5 inches of rain across the warned 
area overnight. Some roads are closed due to flooding.

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...
  Oshkosh, Manitowoc, Chilton, Brillion, Cleveland, Valders, St. 
  Nazianz, Two Creeks, Camp Rokilio Scout Camp, St Anna, High Cliff 
  State Park, Two Rivers, Harrison, Kiel, New Holstein, Sherwood, 
  Newton and Cato.

Runoff from the heavy rains will continue, and it will take a little 
while for standing water to subside.  In addition, occasional light 
rain and drizzle may linger for another hour or two before ending.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Be aware of your surroundings and do not drive on flooded roads.

Turn around, don't drown when encountering flooded roads. Most flood 
deaths occur in vehicles.

&&

LAT...LON 4389 8864 4412 8856 4433 8749 4418 8745
      4407 8759 4390 8767 4389 8816 4394 8816
      4394 8840 4389 8840

FLASH FLOOD...RADAR AND GAUGE INDICATED

$$

Skowronski

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 14, 7:49 PM CDTSpecial Weather StatementGRBBrown, Calumet, Kewaunee, Manitowoc, Outagamie, Portage and 4 more41 min
Jul 14, 8:44 PM CDTSpecial Weather StatementGRBBrown, Calumet, Manitowoc, Outagamie, Waupaca, Waushara and 1 more31 min
Jul 14, 10:06 PM CDTSpecial Weather StatementGRBBrown, Calumet, Door, Kewaunee, Manitowoc, Outagamie and 2 more54 min
Jul 14, 10:48 PM CDTAreal Flood AdvisoryGRBBrown, Calumet, Kewaunee, Manitowoc, Outagamie, Winnebago6 hr
Jul 14, 11:31 PM CDTFlash Flood WarningGRBCalumet, Manitowoc, Winnebago3 hr
Jul 15, 5:22 AM CDTRiver Flood WarningGRBManitowoc11 hr
Jul 15, 5:56 AM CDTAreal Flood AdvisoryGRBCalumet, Manitowoc, Winnebago3 hr
Jul 15, 3:13 PM CDTRiver Flood WarningGRBBrown7 hr

Nearby

Flash Flood Warnings in Wisconsin, 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.