Alert archive / Iowa / Severe Thunderstorm Warnings in 2021
Severe Thunderstorm Warning 74, NWS La Crosse, WI
NWS La Crosse, WI issued this severe thunderstorm warning at Aug 10, 2021, 2:43 PM CDT for 4 counties in Iowa. It was in force for 62 min. 6 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, 2:43 PM CDT (19:43 UTC)
- Expired
- Aug 10, 2021, 3:45 PM CDT
- In force
- 62 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, Fayette County, IA, Winneshiek County, IA
The radar
The La Crosse radar (KARX), 124 km from the middle of the area, began a volume at 19:45 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 |
|---|---|---|---|
| Aug 10, 2:49 PM CDT | TSTM WND GST 45 | Fayette, IA | NUMEROUS LARGE BRANCHES BLOWN DOWN. |
| Aug 10, 2:50 PM CDT | TSTM WND DMG | Fayette, IA | SMALL SHED ROLLED. SOME CORN AND BEAN FLATTENED. |
| Aug 10, 2:52 PM CDT | TSTM WND DMG | Clermont, IA | LOST 10 FOOT TOP OF A PINE TREE. ANOTHER BIG TREE SPLIT. GRILL BLOWN 10 FEET ALMOST THROUGH CANOE INTO SONS TRUCK. |
| Aug 10, 2:55 PM CDT | TSTM WND GST 39 | 3 W Oelwein, IA | AWOS STATION KOLZ OELWEIN MUNICIPAL AIRPORT. |
| Aug 10, 3:02 PM CDT | TSTM WND DMG | 1 S West Union, IA | NUMEROUS 2 TO 8 INCH DIAMETER BRANCHES BLOWN DOWN. |
| Aug 10, 3:03 PM CDT | TSTM WND DMG | West Union, IA | POWER 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.
| 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, 7.7 hours before the alert went out and 172 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.
- 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
The text
As transmitted.
976
WUUS53 KARX 101943
SVRARX
IAC005-043-065-191-102045-
/O.NEW.KARX.SV.W.0074.210810T1943Z-210810T2045Z/
BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service La Crosse WI
243 PM CDT Tue Aug 10 2021
The National Weather Service in La Crosse has issued a
* Severe Thunderstorm Warning for...
Clayton County in northeastern Iowa...
Fayette County in northeastern Iowa...
Southwestern Allamakee County in northeastern Iowa...
Southern Winneshiek County in northeastern Iowa...
* Until 345 PM CDT.
* At 243 PM CDT, severe thunderstorms were located along a line
extending from Waucoma to near Hawkeye to near Fairbank, moving
east at 35 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, Elkader, Postville, Monona, Fayette,
Strawberry Point, Fairbank, Calmar, Edgewood, Ossian, Elgin,
Clermont, Maynard, Hawkeye, Arlington, Spillville, Fort Atkinson,
Farmersburg and Volga.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
For your protection move to an interior room on the lowest floor of a
building.
&&
LAT...LON 4264 9208 4266 9208 4287 9196 4320 9202
4320 9126 4265 9125 4264 9197
TIME...MOT...LOC 1943Z 250DEG 33KT 4304 9203 4289 9194 4264 9212
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH
$$
Skow3 follow-up statements
894
WWUS53 KARX 102007
SVSARX
Severe Weather Statement
National Weather Service La Crosse WI
307 PM CDT Tue Aug 10 2021
IAC005-043-065-191-102045-
/O.CON.KARX.SV.W.0074.000000T0000Z-210810T2045Z/
Clayton IA-Fayette IA-Allamakee IA-Winneshiek IA-
307 PM CDT Tue Aug 10 2021
...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 345 PM CDT
FOR CLAYTON...FAYETTE...SOUTHWESTERN ALLAMAKEE AND SOUTHEASTERN
WINNESHIEK COUNTIES...
At 307 PM CDT, severe thunderstorms were located along a line
extending from near Ossian to Elgin to near Arlington, moving east at
40 mph.
HAZARD...60 mph wind gusts and quarter size hail.
SOURCE...Radar indicated.
IMPACT...Hail damage to vehicles is expected. Expect wind damage to
roofs, siding, and trees.
Locations impacted include...
Oelwein, West Union, Elkader, Postville, Monona, Fayette, Strawberry
Point, Edgewood, Ossian, Elgin, Clermont, Maynard, Arlington,
Farmersburg, Volga, Stanley, Hardin, Luana, Wadena and Castalia.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
For your protection move to an interior room on the lowest floor of a
building.
Torrential rainfall is occurring with these storms, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.
&&
LAT...LON 4289 9184 4309 9195 4320 9160 4320 9126
4265 9125 4264 9197 4265 9200
TIME...MOT...LOC 2007Z 249DEG 33KT 4311 9179 4296 9167 4271 9165
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH
$$
Skow676
WWUS53 KARX 102019
SVSARX
Severe Weather Statement
National Weather Service La Crosse WI
319 PM CDT Tue Aug 10 2021
IAC005-043-065-191-102045-
/O.CON.KARX.SV.W.0074.000000T0000Z-210810T2045Z/
Clayton IA-Fayette IA-Allamakee IA-Winneshiek IA-
319 PM CDT Tue Aug 10 2021
...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 345 PM CDT
FOR CLAYTON...EASTERN FAYETTE...SOUTHWESTERN ALLAMAKEE AND
SOUTHEASTERN WINNESHIEK COUNTIES...
At 318 PM CDT, severe thunderstorms were located along a line
extending from near Ossian to near Elgin to near Strawberry Point,
moving east at 40 mph.
HAZARD...60 mph wind gusts and quarter size hail.
SOURCE...Law enforcement. At 3:20pm, trees and powerlines were
reported down across Fayette County.
IMPACT...Hail damage to vehicles is expected. Expect wind damage to
roofs, siding, and trees.
Locations impacted include...
Elkader, Postville, Monona, Strawberry Point, Edgewood, Ossian,
Elgin, Clermont, Arlington, Farmersburg, Volga, Hardin, Luana,
Wadena, Castalia, St. Olaf, Garber, Elkport, Volney and Mederville.
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 4289 9168 4303 9172 4312 9185 4320 9160
4320 9126 4265 9125 4264 9176
TIME...MOT...LOC 2018Z 250DEG 33KT 4314 9168 4299 9156 4274 9154
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.00 IN
WIND THREAT...OBSERVED
MAX WIND GUST...60 MPH
$$
Skow111
WWUS53 KARX 102034
SVSARX
Severe Weather Statement
National Weather Service La Crosse WI
334 PM CDT Tue Aug 10 2021
IAC065-191-102044-
/O.CAN.KARX.SV.W.0074.000000T0000Z-210810T2045Z/
Fayette IA-Winneshiek IA-
334 PM CDT Tue Aug 10 2021
...THE SEVERE THUNDERSTORM WARNING FOR EASTERN FAYETTE AND
SOUTHEASTERN WINNESHIEK COUNTIES IS CANCELLED...
The storms which prompted the warning have moved out of the warned
area. Therefore, the warning has been cancelled.
A Severe Thunderstorm Watch remains in effect until 800 PM CDT for
northeastern Iowa.
LAT...LON 4266 9148 4294 9141 4308 9160 4314 9161
4318 9161 4320 9160 4320 9126 4265 9125
TIME...MOT...LOC 2034Z 250DEG 33KT 4319 9151 4304 9139 4279 9137
$$
IAC005-043-102045-
/O.CON.KARX.SV.W.0074.000000T0000Z-210810T2045Z/
Clayton IA-Allamakee IA-
334 PM CDT Tue Aug 10 2021
...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 345 PM CDT
FOR WESTERN CLAYTON AND SOUTHWESTERN ALLAMAKEE COUNTIES...
At 334 PM CDT, severe thunderstorms were located along a line
extending from near Waukon to Monona to near Elkader, moving east at
40 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...
Elkader, Postville, Monona, Farmersburg, Hardin, Luana, St. Olaf,
Garber, Elkport, Volney, Spook Cave Campground, Mederville, Giard,
Watson, Bixby State Park, County Roads X 16 And W 48, State Road 51
And County W 48, National, Osborne and Rossville.
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 9148 4294 9141 4308 9160 4314 9161
4318 9161 4320 9160 4320 9126 4265 9125
TIME...MOT...LOC 2034Z 250DEG 33KT 4319 9151 4304 9139 4279 9137
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.00 IN
WIND THREAT...OBSERVED
MAX WIND GUST...60 MPH
$$
SkowThe office that day
Everything else NWS La Crosse, WI issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 10, 2:10 PM CDT | Severe Thunderstorm Warning | ARX | Chickasaw, Fayette, Winneshiek | 50 min |
| Aug 10, 2:26 PM CDT | Heat Advisory | ARX | Clayton | 27 hr |
| Aug 10, 3:23 PM CDT | Severe Thunderstorm Warning | ARX | Allamakee, Clayton | 52 min |
| Aug 10, 3:56 PM CDT | Severe Thunderstorm Warning | ARX | Allamakee | 64 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.