Alert archive / Wisconsin / Flash Flood Warnings in 2017

Flash Flood Warning 7, NWS La Crosse, WI

July 11, 2017Grant County, Wisconsin

NWS La Crosse, WI issued this flash flood warning at Jul 11, 2017, 11:42 PM CDT for Grant County, Wisconsin. It was in force for 3 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 11, 2017, 11:42 PM CDT (04:42 UTC)
Expired: Jul 12, 2017, 2:45 AM CDT
In force: 3 hr
Issued by: NWS La Crosse, WI
Area: Storm-based polygon
Flood severity: None

County Grant County, WI

The radar

The La Crosse radar (KARX), 119 km from the middle of the area, began a volume at 04:45 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
Jul 12, 2:50 AM CDT	FLASH FLOOD	Cassville, WI	ROCK SLIDE ALONG COUNTY ROAD VV AND ROAD WASHOUT NEAR CASSVILLE.
Jul 12, 2:50 AM CDT	FLASH FLOOD	Cassville, WI	ROCK SLIDE ALONG COUNTY ROAD VV AND ROAD WASHOUT NEAR CASSVILLE.

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, 4.7 hours before the alert went out and 134 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: 1096 J/kg
Mixed-layer CIN: -33 J/kg
Mixed-layer LCL: 755 m above ground
0-6 km bulk shear: 44 kt
0-1 km storm-relative helicity: 268 m²/s²
0-3 km storm-relative helicity: 315 m²/s²
Significant tornado parameter: 1.5
Supercell composite: 7.6

Open this sounding in Storm Lab

The text

As transmitted.

047 
WGUS53 KARX 120442
FFWARX
WIC043-120745-
/O.NEW.KARX.FF.W.0007.170712T0442Z-170712T0745Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service La Crosse WI
1142 PM CDT TUE JUL 11 2017

The National Weather Service in La Crosse has issued a

* Flash Flood Warning for...
  Southwestern Grant County in southwestern Wisconsin...

* Until 245 AM CDT

* At 1140 PM CDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. 2 to 4 inches of rain have 
  fallen in parts of the warned area. Flash flooding is expected to 
  begin shortly.

* Some locations that will experience flooding include...
  Cassville, Beetown, Glen Haven, Big H Campground, Porters Bridge,
  Burton, North Andover and Nelson Dewey State Park.

Additional rainfall amounts of 1 to locally 3 inches are possible in 
the warned area.

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 9093 4272 9100 4272 9102 4274 9104
      4274 9106 4275 9107 4276 9106 4277 9107
      4283 9108 4283 9110 4285 9109 4287 9110
      4285 9082 4265 9076

$$

RRS

1 follow-up statement

897 
WGUS73 KARX 120622
FFSARX

Flash Flood Statement
National Weather Service La Crosse WI
122 AM CDT WED JUL 12 2017

WIC043-120745-
/O.CON.KARX.FF.W.0007.000000T0000Z-170712T0745Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Grant WI-
122 AM CDT WED JUL 12 2017

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 245 AM CDT FOR
SOUTHWESTERN GRANT COUNTY...

At 118 AM CDT, Doppler radar indicated thunderstorms producing heavy 
rain across the warned area. Radar estimates that 2 to as much as 6 
inches of rain have fallen since 8 pm last evening. Flash flooding 
or mudslides are expected in the warned area.

Additional rainfall amounts of up to an inch are possible in the 
warned area.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Be especially cautious at night when it is harder to recognize the
dangers of flooding. Turn around, don't drown. 

Please report flooding to your local law enforcement agency when you
can do so safely.

&&

LAT...LON 4268 9093 4272 9100 4272 9102 4274 9104
      4274 9106 4275 9107 4276 9106 4277 9107
      4283 9108 4283 9110 4285 9109 4287 9110
      4285 9082 4265 9076

$$

RRS

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 11, 8:04 PM CDT	Special Weather Statement	ARX	Grant	71 min
Jul 11, 8:51 PM CDT	Special Weather Statement	ARX	Grant	24 min
Jul 11, 9:26 PM CDT	Areal Flood Advisory	ARX	Grant	3 hr
Jul 11, 9:44 PM CDT	Severe Thunderstorm Warning	ARX	Grant	61 min
Jul 12, 12:34 AM CDT	Flash Flood Warning	ARX	Grant	3 hr
Jul 12, 2:47 AM CDT	Areal Flood Warning	ARX	Grant	3 hr
Jul 12, 6:03 AM CDT	Special Weather Statement	ARX	Crawford, Richland, Vernon	42 min
Jul 12, 6:26 AM CDT	Special Weather Statement	ARX	Juneau, Vernon	34 min
Jul 12, 9:53 AM CDT	Severe Thunderstorm Warning	ARX	Grant	31 min
Jul 12, 3:40 PM CDT	Special Weather Statement	ARX	Clark, Taylor	65 min
Jul 12, 4:42 PM CDT	Special Weather Statement	ARX	Clark	63 min
Jul 12, 5:08 PM CDT	Special Weather Statement	ARX	Taylor	37 min
Jul 12, 6:11 PM CDT	Severe Thunderstorm Warning	ARX	Juneau, Monroe, Richland, Vernon	36 min
Jul 12, 6:58 PM CDT	Special Weather Statement	ARX	La Crosse	62 min

Nearby

Flash Flood Warnings in Wisconsin, 2017 Every flash flood warning in 2017

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.