Alert archive / Wisconsin / Flash Flood Warnings in 2018

Flash Flood Warning 3, NWS Milwaukee, WI

August 16, 2018Rock County, Wisconsin

NWS Milwaukee, WI issued this flash flood warning at Aug 16, 2018, 11:22 PM CDT for Rock County, Wisconsin. It was in force for 4 hr. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Aug 16, 2018, 11:22 PM CDT (04:22 UTC)
Expired
Aug 17, 2018, 3:15 AM CDT
In force
4 hr
Issued by
NWS Milwaukee, WI
Area
Storm-based polygon
Flood severity
None

County Rock County, WI

The radar

The Milwaukee radar (KMKX), 39 km from the middle of the area, began a volume at 04:25 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.

The nearest sounding before it

Davenport, (KDVN), launched 00:00Z, 4.4 hours before the alert went out and 181 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, Davenport, at 00:00Z on 2018-08-17Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1949 joules per kilogram.LCLEL10008507005003002001001 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, Davenport, at 00:00Z on 2018-08-17The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 30 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
1949 J/kg
Mixed-layer CIN
-2 J/kg
Mixed-layer LCL
837 m above ground
0-6 km bulk shear
21 kt
0-1 km storm-relative helicity
30 m²/s²
0-3 km storm-relative helicity
57 m²/s²
Significant tornado parameter
0.3
Supercell composite
2.6

Open this sounding in Storm Lab

The text

As transmitted.

395 
WGUS53 KMKX 170422
FFWMKX
WIC105-170815-
/O.NEW.KMKX.FF.W.0003.180817T0422Z-180817T0815Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Milwaukee/Sullivan WI
1122 PM CDT THU AUG 16 2018

The National Weather Service in Milwaukee/Sullivan has issued a

* Flash Flood Warning for...
  Northeastern Rock County in south central Wisconsin...

* Until 315 AM CDT.

* At 1120 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 expected to begin shortly.

* Some locations that will experience flooding include...
  Janesville, Milton and Johnstown Center. 

Several roads are already closed and impassable in the Milton area. 
Additional rainfall is expected over the next 1 to 2 hours, which 
will enhance the flood threat. 

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 4268 8899 4285 8905 4285 8900 4284 8879
      4265 8878

$$

BOXELL
2 follow-up statements
737 
WGUS73 KMKX 170639
FFSMKX

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

WIC105-170815-
/O.CON.KMKX.FF.W.0003.000000T0000Z-180817T0815Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Rock WI-
139 AM CDT FRI AUG 17 2018

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 315 AM CDT FOR
NORTHEASTERN ROCK COUNTY...

At 136 AM CDT, Doppler radar estimated that up to four inches of 
heavy rain fell across the warned area late Thursday evening. 
Several roads are closed and impassable in the Milton area.  

Some locations that will experience flooding include...
Janesville, Milton and Johnstown Center. 

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 4268 8899 4285 8905 4285 8900 4284 8879
      4265 8878

$$

MRC
634 
WGUS73 KMKX 170811
FFSMKX

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

WIC105-170819-
/O.EXP.KMKX.FF.W.0003.000000T0000Z-180817T0815Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Rock WI-
311 AM CDT FRI AUG 17 2018

...THE FLASH FLOOD WARNING FOR NORTHEASTERN ROCK COUNTY WILL EXPIRE
AT 315 AM CDT...

Flood waters have receded and the affected highways are open now. 
Flooding is no longer expected to pose a threat, but light rain will 
persist at times today. Please continue to use caution when driving 
at night- turn around if you encounter standing water on roads.

LAT...LON 4268 8899 4285 8905 4285 8900 4284 8879
      4265 8878

$$

MRC

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 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, 9:20 AM CDTFlash 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.