Alert archive / Iowa / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 73, NWS La Crosse, WI

August 10, 2021Chickasaw County, Fayette County, Winneshiek County, Iowa

NWS La Crosse, WI issued this severe thunderstorm warning at Aug 10, 2021, 2:10 PM CDT for Chickasaw County, Fayette County, Winneshiek County, Iowa. It was in force for 50 min. 5 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, 2:10 PM CDT (19:10 UTC)
Expired
Aug 10, 2021, 3:00 PM CDT
In force
50 min
Issued by
NWS La Crosse, WI
Area
Storm-based polygon
Hail
1.0 in
Wind
60.0 mph

Counties Chickasaw County, IA, Fayette County, IA, Winneshiek County, IA

The radar

The La Crosse radar (KARX), 128 km from the middle of the area, began a volume at 19:09 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 10, 2:49 PM CDTTSTM WND GST 45Fayette, IANUMEROUS LARGE BRANCHES BLOWN DOWN.
Aug 10, 2:50 PM CDTTSTM WND DMGFayette, IASMALL SHED ROLLED. SOME CORN AND BEAN FLATTENED.
Aug 10, 2:55 PM CDTTSTM WND GST 393 W Oelwein, IAAWOS STATION KOLZ OELWEIN MUNICIPAL AIRPORT.
Aug 10, 3:02 PM CDTTSTM WND DMG1 S West Union, IANUMEROUS 2 TO 8 INCH DIAMETER BRANCHES BLOWN DOWN.
Aug 10, 3:03 PM CDTTSTM WND DMGWest Union, IAPOWER LINES BLOWN DOWN.

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.

IssuedProductOfficeLasted
Aug 10, 2:08 PM CDTSevere Thunderstorm WatchSPC6 hr

The nearest sounding before it

Davenport, (KDVN), launched 12:00Z, 7.2 hours before the alert went out and 191 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 12:00Z on 2021-08-10Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 3755 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, Davenport, at 12:00Z on 2021-08-10The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -37 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
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.

255 
WUUS53 KARX 101910
SVRARX
IAC037-065-191-102000-
/O.NEW.KARX.SV.W.0073.210810T1910Z-210810T2000Z/

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

The National Weather Service in La Crosse has issued a

* Severe Thunderstorm Warning for...
  Fayette County in northeastern Iowa...
  Southwestern Winneshiek County in northeastern Iowa...
  Chickasaw County in northeastern Iowa...

* Until 300 PM CDT.

* At 210 PM CDT, a severe thunderstorm was located near Tripoli, or
  12 miles northeast of Waverly, moving northeast at 40 mph.

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

  SOURCE...Radar indicated.

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

* Locations impacted include...
  Oelwein, New Hampton, West Union, Fayette, Fairbank, Calmar,
  Fredericksburg, Maynard, Hawkeye, Lawler, Fort Atkinson, Waucoma,
  Stanley, Jerico, Westgate, St. Lucas, Randalia, Jackson Junction,
  Donnan and Festina.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

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

&&

LAT...LON 4264 9208 4291 9208 4291 9252 4321 9230
      4319 9183 4264 9174
TIME...MOT...LOC 1910Z 236DEG 36KT 4287 9232 

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

$$

Skow
3 follow-up statements
590 
WWUS53 KARX 101913
SVSARX

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

IAC037-065-191-102000-
/O.CON.KARX.SV.W.0073.000000T0000Z-210810T2000Z/
Fayette IA-Winneshiek IA-Chickasaw IA-
213 PM CDT Tue Aug 10 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 300 PM CDT
FOR FAYETTE...SOUTHWESTERN WINNESHIEK AND CHICKASAW COUNTIES...

At 212 PM CDT, a severe thunderstorm was located near Tripoli, or 12
miles south of New Hampton, moving northeast at 40 mph.

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

SOURCE...Trained weather spotters. At 2:08pm, quarter size hail was 
         reported near Frederika.

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

Locations impacted include...
Oelwein, New Hampton, West Union, Fayette, Fairbank, Calmar,
Fredericksburg, Maynard, Hawkeye, Lawler, Fort Atkinson, Waucoma,
Stanley, Jerico, Westgate, St. Lucas, Randalia, Jackson Junction,
Donnan and Festina.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

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

&&

LAT...LON 4264 9208 4291 9208 4291 9252 4321 9230
      4319 9183 4264 9174
TIME...MOT...LOC 1912Z 236DEG 36KT 4289 9229 

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

$$

Skow
181 
WWUS53 KARX 101929
SVSARX

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

IAC037-065-191-102000-
/O.CON.KARX.SV.W.0073.000000T0000Z-210810T2000Z/
Fayette IA-Winneshiek IA-Chickasaw IA-
229 PM CDT Tue Aug 10 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 300 PM CDT
FOR FAYETTE...SOUTHWESTERN WINNESHIEK AND EASTERN CHICKASAW
COUNTIES...

At 229 PM CDT, severe thunderstorms were located along a line
extending from near Lawler to near Fairbank, moving northeast at 40
mph.

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

SOURCE...Trained weather spotters.

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

Locations impacted include...
Oelwein, West Union, Fayette, Fairbank, Calmar, Fredericksburg,
Maynard, Hawkeye, Lawler, Fort Atkinson, Waucoma, Stanley, Westgate,
St. Lucas, Randalia, Jackson Junction, Donnan, Festina, Eldorado and
Lake Meyer County Park.

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 4264 9208 4291 9208 4291 9236 4321 9221
      4319 9183 4264 9174
TIME...MOT...LOC 1929Z 246DEG 35KT 4302 9216 4267 9211 

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

$$

Skow
701 
WWUS53 KARX 101948
SVSARX

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

IAC037-101957-
/O.CAN.KARX.SV.W.0073.000000T0000Z-210810T2000Z/
Chickasaw IA-
248 PM CDT Tue Aug 10 2021

...THE SEVERE THUNDERSTORM WARNING FOR EASTERN CHICKASAW COUNTY IS
CANCELLED...

The storms which prompted the warning have moved out of the warned 
area. Therefore, the warning has been cancelled.

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

LAT...LON 4264 9208 4308 9208 4319 9183 4264 9174
TIME...MOT...LOC 1947Z 238DEG 33KT 4309 9194 4264 9204 

$$

IAC065-191-102000-
/O.CON.KARX.SV.W.0073.000000T0000Z-210810T2000Z/
Fayette IA-Winneshiek IA-
248 PM CDT Tue Aug 10 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 300 PM CDT
FOR FAYETTE AND SOUTH CENTRAL WINNESHIEK COUNTIES...

At 247 PM CDT, severe thunderstorms were located along a line 
extending from near Fort Atkinson to Fairbank, moving east-northeast 
at 40 mph.

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

SOURCE...Radar indicated.

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

Locations impacted include...
Oelwein, West Union, Fayette, Fairbank, Calmar, Maynard, Hawkeye,
Fort Atkinson, Waucoma, Stanley, Westgate, St. Lucas, Randalia,
Jackson Junction, Donnan, Festina, Eldorado, Waucoma Campground,
County Road W 33 And 187 and Highway 93 And County W 14.

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 4264 9208 4308 9208 4319 9183 4264 9174
TIME...MOT...LOC 1947Z 238DEG 33KT 4309 9194 4264 9204 

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

$$

Skow

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 10, 2:26 PM CDTHeat AdvisoryARXClayton27 hr
Aug 10, 2:43 PM CDTSevere Thunderstorm WarningARXAllamakee, Clayton, Fayette, Winneshiek62 min
Aug 10, 3:23 PM CDTSevere Thunderstorm WarningARXAllamakee, Clayton52 min
Aug 10, 3:56 PM CDTSevere Thunderstorm WarningARXAllamakee64 min

Nearby

Severe Thunderstorm Warnings in Iowa, 2021Every 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.