Alert archive / Wisconsin / Flash Flood Warnings in 2018

Flash Flood Warning 6, NWS Milwaukee, WI

August 20, 2018Dane County, Wisconsin

NWS Milwaukee, WI issued this flash flood warning at Aug 20, 2018, 8:26 PM CDT for Dane County, Wisconsin. It was in force for 3 hr. 9 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 20, 2018, 8:26 PM CDT (01:26 UTC)
Expired: Aug 20, 2018, 11:15 PM CDT
In force: 3 hr
Issued by: NWS Milwaukee, WI
Area: Storm-based polygon
Flood severity: None

County Dane County, WI

The radar

The Milwaukee radar (KMKX), 82 km from the middle of the area, began a volume at 01:29 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 20, 8:54 PM CDT	HEAVY RAIN 4	3 S Shorewood Hills, WI
Aug 20, 8:55 PM CDT	HEAVY RAIN 4.97	2 Wnw Middleton, WI	MIDDLETON MUNICIPAL AIRPORT.
Aug 20, 9:00 PM CDT	HEAVY RAIN 7.8	3 Sw Shorewood Hills, WI
Aug 20, 9:12 PM CDT	HEAVY RAIN 8.13	4 Se Cross Plains, WI
Aug 20, 9:36 PM CDT	FLASH FLOOD	1 Sse Mount Horeb, WI	HWY 151 NEAR MT HOREB IS CLOSED DUE TO FLOODING.
Aug 20, 9:36 PM CDT	FLASH FLOOD	4 W Middleton, WI	PARTS OF HWY 14 ARE CLOSED BETWEEN CROSS PLAINS AND MIDDLETON DUE TO FLOODED ROADS.
Aug 20, 10:15 PM CDT	FLASH FLOOD	2 Ssw Middleton, WI	RELAYED REPORT OF 30 PEOPLE FROM A HEALTH CLINIC BEING EVACUATED, REQUESTING A WATER RESCUE AND BUS.
Aug 20, 10:34 PM CDT	HEAVY RAIN 11.05	3 W Middleton, WI
Aug 20, 11:00 PM CDT	HEAVY RAIN 10.23	2 S Middleton, WI

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

The nearest sounding before it

Davenport, (KDVN), launched 00:00Z, 1.4 hours before the alert went out and 183 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: 947 J/kg
Mixed-layer CIN: -28 J/kg
Mixed-layer LCL: 824 m above ground
0-6 km bulk shear: 9 kt
0-1 km storm-relative helicity: 4 m²/s²
0-3 km storm-relative helicity: -2 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

172 
WGUS53 KMKX 210126
FFWMKX
WIC025-210415-
/O.NEW.KMKX.FF.W.0006.180821T0126Z-180821T0415Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Milwaukee/Sullivan WI
826 PM CDT MON AUG 20 2018

The National Weather Service in Milwaukee/Sullivan has issued a

* Flash Flood Warning for...
  Dane County in south central Wisconsin...

* Until 1115 PM CDT.

* At 818 PM CDT, local law enforcement reported flash flooding 
  across the warned area. Four to seven inches of rain have fallen 
  on the west side of Madison, as well as Middleton, Cross Plains, 
  Mount Horeb and areas west of Verona. 

  Several reports of flooded intersections and roads, with several 
stranded vehicles, have been reported across the west side of 
Madison, along with the Middleton area, over the past few hours. 

  More thunderstorms are developing and are expected to move into 
the warned area over the next few hours. An additional two to four 
inches of rain is possible in the warned area, over the next few 
hours. Any additional heavy rainfall will only enhance the flash 
flooding in these areas.

* Some locations that will experience flooding include...
  Madison, Sun Prairie, Fitchburg, Middleton, Stoughton, Waunakee,
  Verona, Oregon, McFarland, Monona, Mount Horeb, Windsor, Sauk City,
  Deforest, Cross Plains, Belleville, Mazomanie, Shorewood Hills,
  Brooklyn and Black Earth.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Excessive runoff from heavy rainfall will cause flooding of small
creeks and streams, urban areas, highways, streets and underpasses as
well as other drainage areas and low lying spots.

&&

LAT...LON 4286 8937 4286 8984 4321 8984 4323 8981
      4324 8977 4328 8971 4329 8971 4329 8937
      4328 8936 4328 8925 4285 8924 4285 8937

$$

WOOD

1 follow-up statement

787 
WGUS73 KMKX 210149
FFSMKX

Flash Flood Statement
National Weather Service Milwaukee/Sullivan WI
849 PM CDT MON AUG 20 2018

WIC025-210415-
/O.CON.KMKX.FF.W.0006.000000T0000Z-180821T0415Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Dane WI-
849 PM CDT MON AUG 20 2018

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 1115 PM CDT FOR
DANE COUNTY...

At 847 PM CDT, Doppler radar and automated rain gauges indicated
thunderstorms producing heavy rain remain over western Dane 
County.  Radar estimates between 4 to 8 inches of rain has 
fallen over parts of western Dane County including Middleton, 
Cross Plains Black Earth and Mount Vernon. Flash flooding is 
ongoing in these areas. 

Other locations that may experience additional flooding include...
Madison, Sun Prairie, Fitchburg, Middleton, Stoughton, Waunakee,
Verona, Oregon, McFarland, Monona, Mount Horeb, Windsor, Sauk City,
Deforest, Cross Plains, Belleville, Mazomanie, Shorewood Hills,
Brooklyn and Black Earth.

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.

In hilly terrain there are hundreds of low water crossings which are
potentially dangerous in heavy rain. Do not attempt to cross flooded
roads. Find an alternate route.

&&

LAT...LON 4286 8937 4286 8984 4321 8984 4323 8981
      4324 8977 4328 8971 4329 8971 4329 8937
      4328 8936 4328 8925 4285 8924 4285 8937

$$

MBK

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 20, 7:07 PM CDT	Areal Flood Advisory	MKX	Green, Lafayette, Rock	3 hr
Aug 20, 9:43 PM CDT	River Flood Warning	MKX	Green, Rock	6 days
Aug 20, 9:45 PM CDT	River Flood Watch	MKX	Lafayette	14 hr
Aug 20, 10:38 PM CDT	Areal Flood Advisory	MKX	Columbia, Dane, Dodge, Jefferson, Milwaukee, Washington and 1 more	3 hr
Aug 20, 11:56 PM CDT	Areal Flood Warning	MKX	Dane	30 hr
Aug 21, 12:08 AM CDT	River Flood Warning	MKX	Dane	22 hr
Aug 21, 12:11 AM CDT	Areal Flood Advisory	MKX	Columbia, Dodge, Fond du Lac, Green Lake, Marquette, Milwaukee and 4 more	3 hr
Aug 21, 5:24 AM CDT	Special Marine Warning	MKX		66 min
Aug 21, 6:16 AM CDT	Special Marine Warning	MKX		59 min
Aug 21, 6:38 AM CDT	Special Marine Warning	MKX		37 min
Aug 21, 11:41 AM CDT	River Flood Warning	MKX	Lafayette	28 hr
Aug 21, 5:26 PM CDT	Areal Flood Warning	MKX	Dane	23 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.