Alert archive / Wisconsin / Flash Flood Warnings in 2017

Flash Flood Warning 8, NWS La Crosse, WI

July 12, 2017Grant County, Wisconsin

NWS La Crosse, WI issued this flash flood warning at Jul 12, 2017, 12:34 AM CDT for Grant County, Wisconsin. It was in force for 3 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: Jul 12, 2017, 12:34 AM CDT (05:34 UTC)
Expired: Jul 12, 2017, 3:30 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 Quad Cities radar (KDVN), 108 km from the middle of the area, began a volume at 05:38 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, 5.6 hours before the alert went out and 108 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.

762 
WGUS53 KARX 120534
FFWARX
WIC043-120830-
/O.NEW.KARX.FF.W.0008.170712T0534Z-170712T0830Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service La Crosse WI
1234 AM CDT WED JUL 12 2017

The National Weather Service in La Crosse has issued a

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

* Until 330 AM CDT

* At 1232 AM CDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Radar estimates that 1 to 
  locally 3 inches of rain have fallen since 1115 pm near the 
  Mississippi RIver. Flash flooding is expected to begin shortly.

* Some locations that will experience flooding include...
  Cuba City, Hazel Green, Dickeyville, Georgetown, Potosi, Tennyson,
  Kieler, Lock And Dam 11, Sandy Hook, Louisburg, Sinsinawa and Big
  Patch.

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 4251 9064 4254 9064 4256 9066 4257 9066
      4258 9068 4263 9070 4265 9076 4273 9079
      4266 9043 4251 9042

$$

RRS

1 follow-up statement

945 
WGUS73 KARX 120702
FFSARX

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

WIC043-120830-
/O.CON.KARX.FF.W.0008.000000T0000Z-170712T0830Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Grant WI-
202 AM CDT WED JUL 12 2017

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 330 AM CDT FOR
SOUTHEASTERN GRANT COUNTY...

At 158 AM CDT, Doppler radar indicated thunderstorms producing heavy 
rain across the warned area. Radar estimates 1 to locally 3 inches 
of rain have fallen since 10 pm last evening. Flash flooding or 
mudslides are expected in the warning area.

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

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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. Turn around, don't drown.

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

&&

LAT...LON 4251 9064 4254 9064 4256 9066 4257 9066
      4258 9068 4263 9070 4265 9076 4273 9079
      4266 9043 4251 9042

$$

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 11, 11:42 PM 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.