Alert archive / Wisconsin / Flash Flood Warnings in 2018

Flash Flood Warning 3, NWS Green Bay, WI

September 17, 2018Brown County, Wisconsin

NWS Green Bay, WI issued this flash flood warning at Sep 17, 2018, 8:40 PM CDT for Brown County, Wisconsin. It was in force for 2 hr. 3 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: Sep 17, 2018, 8:40 PM CDT (01:40 UTC)
Expired: Sep 17, 2018, 10:45 PM CDT
In force: 2 hr
Issued by: NWS Green Bay, WI
Area: Storm-based polygon
Flood severity: None

County Brown County, WI

The radar

The Green Bay radar (KGRB), 21 km from the middle of the area, began a volume at 01:39 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
Sep 17, 9:32 PM CDT	HEAVY RAIN 4.29	4 Ese Green Bay, WI	3 INCHES OF WATER REMAIN OVER THE ROAD.
Sep 17, 9:50 PM CDT	FLASH FLOOD	Green Bay, WI	EVACUATIONS OCCURRING IN AT LEAST 2 LOCATIONS. MANY CARS STRANDED. SEVERAL BASEMENTS FLOODED. WORST FLOODING IS ON MAIN STREET FROM LIME KILN TO MANITOWOC ROAD.
Sep 17, 10:43 PM CDT	HEAVY RAIN 6.38	3 Se Green Bay, WI	FLOODED ROADWAYS. MINOR BASEMENT FLOODING.

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, 1.7 hours before the alert went out and 19 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: 1680 J/kg
Mixed-layer CIN: -10 J/kg
Mixed-layer LCL: 1502 m above ground
0-6 km bulk shear: 16 kt
0-1 km storm-relative helicity: 86 m²/s²
0-3 km storm-relative helicity: 109 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

241 
WGUS53 KGRB 180140
FFWGRB
WIC009-180345-
/O.NEW.KGRB.FF.W.0003.180918T0140Z-180918T0345Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Green Bay WI
840 PM CDT MON SEP 17 2018

The National Weather Service in Green Bay has issued a

* Flash Flood Warning for...
  Southeastern Brown County in northeastern Wisconsin...

* Until 1045 PM CDT.

* At 839 PM CDT, Doppler radar indicated thunderstorms producing
  heavy rain across the warned area. Up to three inches of rain have
  already fallen. Flash flooding is ongoing or expected to begin 
  shortly. Another inch or two of rain may fall before the storms 
  shift off to the southeast.

* Some locations that will experience flooding include...
  Green Bay, Denmark, Bellevue Town, De Pere, Ashwaubenon, Bellevue,
  Allouez, Ledgeview, Humboldt and Glenmore.

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 4432 8805 4454 8804 4454 8777 4440 8776
      4433 8777 4433 8789 4432 8789

$$

Skowronski

1 follow-up statement

356 
WGUS73 KGRB 180235
FFSGRB

Flash Flood Statement
National Weather Service Green Bay WI
935 PM CDT MON SEP 17 2018

WIC009-180345-
/O.CON.KGRB.FF.W.0003.000000T0000Z-180918T0345Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Brown WI-
935 PM CDT MON SEP 17 2018

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 1045 PM CDT FOR
SOUTHEASTERN BROWN COUNTY...

Flooding continues over portions of Brown County. Two to five inches 
of rain fell earlier this evening, with heaviest rains occurring on 
the east side of the City of Green Bay. At 928 PM CDT, Doppler radar 
indicated showers continuing across the warning area, though rains 
were much lighter than earlier tonight. The potential for additional 
heavy rainfall had greatly diminished, though flooding will continue 
due to run-off from the earlier heavy rain. 

Some locations experiencing flooding include...Green Bay, Denmark, 
Bellevue Town, De Pere, Bellevue, Allouez, Ledgeview, Humboldt and 
Glenmore.

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 4432 8805 4454 8804 4454 8777 4440 8776
      4433 8777 4433 8789 4432 8789

$$

Skowronski

The office that day

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

Issued	Product	Office	Counties	Lasted
Sep 17, 7:26 PM CDT	Special Weather Statement	GRB	Outagamie	49 min
Sep 17, 7:35 PM CDT	Severe Thunderstorm Warning	GRB	Brown, Outagamie	40 min
Sep 17, 7:43 PM CDT	Special Weather Statement	GRB	Brown	47 min
Sep 17, 7:48 PM CDT	Areal Flood Advisory	GRB	Brown	117 min
Sep 17, 8:29 PM CDT	Special Weather Statement	GRB	Brown	61 min
Sep 17, 8:33 PM CDT	Severe Thunderstorm Warning	GRB	Manitowoc	30 min
Sep 17, 8:36 PM CDT	Special Marine Warning	GRB		39 min
Sep 17, 10:42 PM CDT	Areal Flood Warning	GRB	Brown	5 hr

Nearby

Flash Flood Warnings in Wisconsin, 2018 Every flash flood warning in 2018

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.