Alert archive / Wisconsin / Flash Flood Warnings in 2018

Flash Flood Warning 4, NWS Milwaukee, WI

August 17, 2018Dane County, Dodge County, Jefferson County, Wisconsin

NWS Milwaukee, WI issued this flash flood warning at Aug 17, 2018, 9:20 AM CDT for Dane County, Dodge County, Jefferson County, Wisconsin. It was in force for 3 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
Aug 17, 2018, 9:20 AM CDT (14:20 UTC)
Expired
Aug 17, 2018, 12:15 PM CDT
In force
3 hr
Issued by
NWS Milwaukee, WI
Area
Storm-based polygon
Flood severity
None

Counties Dane County, WI, Dodge County, WI, Jefferson County, WI

The radar

The Milwaukee radar (KMKX), 33 km from the middle of the area, began a volume at 14:25 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
Aug 17, 9:30 AM CDTHEAVY RAIN 4.921 Wsw Watertown, WI24 HOUR TOTAL.
Aug 17, 10:30 AM CDTHEAVY RAIN 61 Wsw Watertown, WISTORM TOTAL.
Aug 17, 12:00 PM CDTHEAVY RAIN 8.61 S Watertown, WISTORM TOTAL.

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 12:00Z, 2.3 hours before the alert went out and 154 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 2018-08-17Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 97 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 2018-08-17The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -8 square meters per square second.1939Sfc1 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
97 J/kg
Mixed-layer CIN
-119 J/kg
Mixed-layer LCL
1089 m above ground
0-6 km bulk shear
3 kt
0-1 km storm-relative helicity
-8 m²/s²
0-3 km storm-relative helicity
9 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

420 
WGUS53 KMKX 171420
FFWMKX
WIC025-027-055-171715-
/O.NEW.KMKX.FF.W.0004.180817T1420Z-180817T1715Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Milwaukee/Sullivan WI
920 AM CDT FRI AUG 17 2018

The National Weather Service in Milwaukee/Sullivan has issued a

* Flash Flood Warning for...
  Northeastern Dane County in south central Wisconsin...
  Northern Jefferson County in southeastern Wisconsin...
  Southwestern Dodge County in southeastern Wisconsin...

* Until 1215 PM CDT.

* At 915 AM CDT, Doppler radar and automated rain gauges indicated 
  heavy rain falling across the warned area. Five to six inches of 
  rain have fallen. Flash flooding is already occurring especially 
  in Watertown. Numerous roads flooded or washed out in Watertown. 
  High water extending from the roads into the yards with basement 
  flooding. This will continue over the next few hours.


* Some locations that will experience flooding include...
  Watertown, Marshall, Waterloo, Ixonia, Richwood, Pipersville,
  Deansville, Hubbleton and Lake Lac La Belle.

Additional rainfall amounts of 1 to 2 inches are possible in the 
warned area.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Flash Flood Warning means that flooding is imminent or occurring.
If you are in the warned area move to higher ground immediately.
Residents living along streams and creeks should take immediate
precautions to protect life and property.

&&

LAT...LON 4312 8854 4312 8912 4328 8911 4329 8906
      4324 8853

$$

GEHRING
1 follow-up statement
670 
WGUS73 KMKX 171501
FFSMKX

Flash Flood Statement
National Weather Service Milwaukee/Sullivan WI
1001 AM CDT FRI AUG 17 2018

WIC025-027-055-171715-
/O.CON.KMKX.FF.W.0004.000000T0000Z-180817T1715Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Dane WI-Jefferson WI-Dodge WI-
1001 AM CDT FRI AUG 17 2018

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 1215 PM CDT FOR
NORTHEASTERN DANE...NORTHERN JEFFERSON AND SOUTHWESTERN DODGE
COUNTIES...

At 953 AM CDT, Doppler radar and automated rain gauges indicated 
that five to seven inches of rain have fallen. Flash flooding is 
already occurring especially in Watertown. Rainfall rates are 
decreasing with rain ending in some areas. Despite a diminishing 
trend, runoff and flash flooding will continue through noon. 
Afterward, standing water will remain over many roads and in yards 
and fields. Many roads may remain closed through the day.   

Some locations that will experience flooding include...
Watertown, Marshall, Waterloo, Ixonia, Richwood, Pipersville,
Deansville, Hubbleton and Lake Lac La Belle.


PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4312 8854 4312 8912 4328 8911 4329 8906
      4324 8853

$$

GEHRING

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 16, 8:35 PM CDTAreal Flood AdvisoryMKXGreen, Rock3 hr
Aug 16, 10:21 PM CDTAreal Flood AdvisoryMKXRock3 hr
Aug 16, 11:22 PM CDTFlash Flood WarningMKXRock4 hr
Aug 17, 6:58 AM CDTSpecial Marine WarningMKX32 min
Aug 17, 7:22 AM CDTAreal Flood AdvisoryMKXDane, Dodge, Jefferson, Waukesha3 hr
Aug 17, 7:35 AM CDTAreal Flood AdvisoryMKXMilwaukee55 min
Aug 17, 8:15 AM CDTAreal Flood WarningMKXDane, Dodge, Jefferson3 hr
Aug 17, 11:08 AM CDTAreal Flood AdvisoryMKXMilwaukee112 min
Aug 17, 12:22 PM CDTAreal Flood WarningMKXDodge, Jefferson21 hr

Nearby

Flash Flood Warnings in Wisconsin, 2018Every 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.