Alert archive / Wisconsin / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 75, NWS La Crosse, WI

August 10, 2021Crawford County, Grant County, Wisconsin; Allamakee County, Clayton County, Iowa

NWS La Crosse, WI issued this severe thunderstorm warning at Aug 10, 2021, 3:23 PM CDT for Crawford County, Grant County, Wisconsin; Allamakee County, Clayton County, Iowa. It was in force for 52 min. 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: Aug 10, 2021, 3:23 PM CDT (20:23 UTC)
Expired: Aug 10, 2021, 4:15 PM CDT
In force: 52 min
Issued by: NWS La Crosse, WI
Area: Storm-based polygon
Hail: 1.0 in
Wind: 60.0 mph

Counties Allamakee County, IA, Clayton County, IA, Crawford County, WI, Grant County, WI

The radar

The La Crosse radar (KARX), 99 km from the middle of the area, began a volume at 20:26 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 10, 4:01 PM CDT	TSTM WND GST 50	Glen Haven, WI	50 MPH WINDS MEASURED ON SETTLEMENT RD.
Aug 10, 4:11 PM CDT	TSTM WND DMG	Potosi, WI	50+MPH WINDS IN POTOSI, SOME BUILDING DAMAGES REPORTED BY FIRE DEPARTMENT.

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

The watch it was issued in

The SPC watch in force over the same counties when this warning went out.

Issued	Product	Office	Lasted
Aug 10, 2:08 PM CDT	Severe Thunderstorm Watch	SPC	6 hr

The nearest sounding before it

Davenport, (KDVN), launched 12:00Z, 8.4 hours before the alert went out and 155 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: 3755 J/kg
Mixed-layer CIN: -67 J/kg
Mixed-layer LCL: 819 m above ground
0-6 km bulk shear: 12 kt
0-1 km storm-relative helicity: -37 m²/s²
0-3 km storm-relative helicity: 4 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

589 
WUUS53 KARX 102023
SVRARX
IAC005-043-WIC023-043-102115-
/O.NEW.KARX.SV.W.0075.210810T2023Z-210810T2115Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service La Crosse WI
323 PM CDT Tue Aug 10 2021

The National Weather Service in La Crosse has issued a

* Severe Thunderstorm Warning for...
  Central Clayton County in northeastern Iowa...
  Allamakee County in northeastern Iowa...
  Central Grant County in southwestern Wisconsin...
  Crawford County in southwestern Wisconsin...

* Until 415 PM CDT.

* At 322 PM CDT, severe thunderstorms were located along a line
  extending from 8 miles east of Waukon to near Strawberry Point,
  moving east at 50 mph.

  HAZARD...60 mph wind gusts and quarter size hail.

  SOURCE...Law enforcement.

  IMPACT...Hail damage to vehicles is expected. Expect wind damage 
           to roofs, siding, and trees.

* Locations impacted include...
  Prairie Du Chien, Waukon, Lancaster, Guttenberg, Lansing, Boscobel,
  Monona, Cassville, McGregor, Edgewood, Garnavillo, Bloomington,
  Marquette, Harpers Ferry, Bridgeport, Seneca, Beetown, Wauzeka,
  Potosi and Soldiers Grove.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

Torrential rainfall is occurring with these storms, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.

&&

LAT...LON 4265 9145 4297 9134 4318 9161 4330 9160
      4342 9122 4342 9067 4266 9069 4266 9082
      4268 9090 4266 9090
TIME...MOT...LOC 2022Z 250DEG 43KT 4325 9131 4265 9155 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.00 IN
WIND THREAT...OBSERVED
MAX WIND GUST...60 MPH

$$

Skow

3 follow-up statements

891 
WWUS53 KARX 102050
SVSARX

Severe Weather Statement
National Weather Service La Crosse WI
350 PM CDT Tue Aug 10 2021

IAC005-043-WIC023-043-102115-
/O.CON.KARX.SV.W.0075.000000T0000Z-210810T2115Z/
Clayton IA-Allamakee IA-Grant WI-Crawford WI-
350 PM CDT Tue Aug 10 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 415 PM CDT
FOR EASTERN CLAYTON...CENTRAL ALLAMAKEE...CENTRAL GRANT AND CRAWFORD
COUNTIES...

At 349 PM CDT, severe thunderstorms were located along a line
extending from 9 miles east of Lansing to 6 miles northeast of
Balltown, moving east at 45 mph.

HAZARD...60 mph wind gusts and nickel size hail.

SOURCE...Law enforcement.

IMPACT...Expect damage to roofs, siding, and trees.

Locations impacted include...
Prairie Du Chien, Waukon, Lancaster, Guttenberg, Lansing, Boscobel,
Cassville, McGregor, Bloomington, Marquette, Harpers Ferry,
Bridgeport, Seneca, Beetown, Wauzeka, Potosi, Soldiers Grove, Mount
Ida, Gays Mills and Eastman.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

Torrential rainfall is occurring with these storms, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.

&&

LAT...LON 4265 9132 4275 9118 4284 9114 4306 9118
      4316 9148 4332 9153 4342 9122 4342 9067
      4266 9069 4266 9082 4268 9090 4266 9090
TIME...MOT...LOC 2049Z 253DEG 39KT 4338 9105 4271 9079 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...0.88 IN
WIND THREAT...OBSERVED
MAX WIND GUST...60 MPH

$$

Skow

737 
WWUS53 KARX 102058
SVSARX

Severe Weather Statement
National Weather Service La Crosse WI
358 PM CDT Tue Aug 10 2021

IAC005-043-WIC023-043-102115-
/O.CON.KARX.SV.W.0075.000000T0000Z-210810T2115Z/
Clayton IA-Allamakee IA-Grant WI-Crawford WI-
358 PM CDT Tue Aug 10 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 415 PM CDT
FOR SOUTHEASTERN CLAYTON...EASTERN ALLAMAKEE...CENTRAL GRANT AND
CRAWFORD COUNTIES...

At 358 PM CDT, severe thunderstorms were located along a line
extending from 10 miles south of Viroqua to 7 miles south of
Lancaster, moving east at 50 mph.

HAZARD...60 mph wind gusts.

SOURCE...Law enforcement.

IMPACT...Expect damage to roofs, siding, and trees.

Locations impacted include...
Lancaster, Lansing, Boscobel, Cassville, Bloomington, Harpers Ferry,
Bridgeport, Seneca, Beetown, Wauzeka, Potosi, Soldiers Grove, Mount
Ida, Gays Mills, Eastman, Tennyson, De Soto, Mount Hope, Mount
Sterling and Patch Grove.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

Torrential rainfall is occurring with these storms, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.

&&

LAT...LON 4266 9119 4276 9107 4286 9103 4311 9111
      4317 9128 4334 9144 4342 9122 4342 9067
      4266 9069 4266 9082 4268 9090 4266 9090
TIME...MOT...LOC 2058Z 250DEG 43KT 4341 9094 4274 9068 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...OBSERVED
MAX WIND GUST...60 MPH

$$

Skow

591 
WWUS53 KARX 102114
SVSARX

Severe Weather Statement
National Weather Service La Crosse WI
414 PM CDT Tue Aug 10 2021

IAC005-043-WIC023-043-102123-
/O.EXP.KARX.SV.W.0075.000000T0000Z-210810T2115Z/
Clayton IA-Allamakee IA-Grant WI-Crawford WI-
414 PM CDT Tue Aug 10 2021

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN CLAYTON...EASTERN
ALLAMAKEE...CENTRAL GRANT AND CRAWFORD COUNTIES WILL EXPIRE AT 415 PM
CDT...
    
The storms which prompted the warning have moved out of the area.
Therefore, the warning will be allowed to expire.

A Severe Thunderstorm Watch remains in effect until 800 PM CDT for
northeastern Iowa...and southwestern Wisconsin.

Remember, a Severe Thunderstorm Warning still remains in effect for
eastern Grant and Crawford Counties.

LAT...LON 4266 9119 4276 9107 4286 9103 4311 9111
      4317 9128 4334 9144 4342 9122 4342 9067
      4266 9069 4266 9082 4268 9090 4266 9090
TIME...MOT...LOC 2113Z 250DEG 43KT 4347 9071 4280 9045 

$$

Skow

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 10, 2:26 PM CDT	Heat Advisory	ARX	Grant	27 hr
Aug 10, 3:56 PM CDT	Severe Thunderstorm Warning	ARX	Crawford, Grant, Richland	64 min
Aug 10, 4:57 PM CDT	Severe Thunderstorm Warning	ARX	Richland	18 min
Aug 10, 2:10 PM CDT	Severe Thunderstorm Warning	ARX	Chickasaw, Fayette, Winneshiek	50 min
Aug 10, 2:43 PM CDT	Severe Thunderstorm Warning	ARX	Allamakee, Clayton, Fayette, Winneshiek	62 min

Nearby

Severe Thunderstorm Warnings in Wisconsin, 2021 Severe Thunderstorm Warnings in Iowa, 2021 Every severe thunderstorm warning in 2021

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.