Alert archive / Iowa / Severe Thunderstorm Warnings in 2021
Severe Thunderstorm Warning 88, NWS La Crosse, WI
NWS La Crosse, WI issued this severe thunderstorm warning at Aug 24, 2021, 1:43 PM CDT for Chickasaw County, Floyd County, Iowa. It was in force for 47 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 24, 2021, 1:43 PM CDT (18:43 UTC)
- Expired
- Aug 24, 2021, 2:30 PM CDT
- In force
- 47 min
- Issued by
- NWS La Crosse, WI
- Area
- Storm-based polygon
- Hail
- 0.75 in
- Wind
- 60.0 mph
Counties Chickasaw County, IA, Floyd County, IA
The radar
The La Crosse radar (KARX), 140 km from the middle of the area, began a volume at 18:47 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 24, 1:57 PM CDT | TSTM WND GST 40 | Charles City, IA | |
| Aug 24, 2:15 PM CDT | TSTM WND DMG | Williamstown, IA | TREES DOWN ALONG HIGHWAY 63 |
| Aug 24, 2:15 PM CDT | TSTM WND DMG | Williamstown, IA | TREES DOWN ALONG HIGHWAY 63. |
| Aug 24, 2:20 PM CDT | TSTM WND DMG | 4 Sw Fredericksburg, IA | TREES REPORTED DOWN |
| Aug 24, 2:20 PM CDT | TSTM WND DMG | 4 Sw Fredericksburg, IA | TREES REPORTED DOWN. |
Local storm reports filed while the alert was in force, from inside its polygon or its counties.
The nearest sounding before it
Minneapolis, MN (KMPX), launched 12:00Z, 6.7 hours before the alert went out and 222 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
- 1192 J/kg
- Mixed-layer CIN
- -180 J/kg
- Mixed-layer LCL
- 1234 m above ground
- 0-6 km bulk shear
- 51 kt
- 0-1 km storm-relative helicity
- 141 m²/s²
- 0-3 km storm-relative helicity
- 178 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 6.9
The text
As transmitted.
930 WUUS53 KARX 241843 SVRARX IAC037-067-241930- /O.NEW.KARX.SV.W.0088.210824T1843Z-210824T1930Z/ BULLETIN - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Warning National Weather Service La Crosse WI 143 PM CDT Tue Aug 24 2021 The National Weather Service in La Crosse has issued a * Severe Thunderstorm Warning for... Southeastern Floyd County in north central Iowa... Southern Chickasaw County in northeastern Iowa... * Until 230 PM CDT. * At 143 PM CDT, severe thunderstorms were located along a line extending from near Charles City to near Greene, moving east at 40 mph. HAZARD...60 mph wind gusts. SOURCE...Radar indicated. IMPACT...Expect damage to roofs, siding, and trees. * Locations impacted include... Charles City, New Hampton, Nashua, Fredericksburg, Lawler, Ionia, Chickasaw, Bassett, Bradford, Oakwood, Powersville, Republic, Highway 18 And County V 18, Bunns Woods County Park, Highway 18 And County V 56, County Roads B 60 And T 64, Midway, Howards Wood Recreational Area, Boyd and Williamstown. PRECAUTIONARY/PREPAREDNESS ACTIONS... For your protection move to an interior room on the lowest floor of a building. && LAT...LON 4308 9282 4309 9208 4291 9208 4291 9278 TIME...MOT...LOC 1843Z 268DEG 34KT 4306 9274 4291 9270 HAIL THREAT...RADAR INDICATED MAX HAIL SIZE...<.75 IN WIND THREAT...RADAR INDICATED MAX WIND GUST...60 MPH $$ Kurz
2 follow-up statements
726 WWUS53 KARX 241905 SVSARX Severe Weather Statement National Weather Service La Crosse WI 205 PM CDT Tue Aug 24 2021 IAC067-241914- /O.CAN.KARX.SV.W.0088.000000T0000Z-210824T1930Z/ Floyd IA- 205 PM CDT Tue Aug 24 2021 ...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN FLOYD COUNTY IS CANCELLED... The storms which prompted the warning have moved out of the warned area. Therefore, the warning has been cancelled. A Severe Thunderstorm Watch remains in effect until 700 PM CDT for northeastern Iowa. LAT...LON 4309 9208 4291 9208 4291 9255 4308 9255 TIME...MOT...LOC 1904Z 269DEG 32KT 4306 9253 4292 9243 $$ IAC037-241930- /O.CON.KARX.SV.W.0088.000000T0000Z-210824T1930Z/ Chickasaw IA- 205 PM CDT Tue Aug 24 2021 ...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 230 PM CDT FOR SOUTHERN CHICKASAW COUNTY... At 204 PM CDT, severe thunderstorms were located along a line extending from near Ionia to 6 miles east of Nashua, moving east at 35 mph. HAZARD...60 mph wind gusts. SOURCE...Radar indicated. IMPACT...Expect damage to roofs, siding, and trees. Locations impacted include... New Hampton, Nashua, Fredericksburg, Lawler, Ionia, Chickasaw, Bassett, Bradford, Boyd, Williamstown, Republic, Highway 18 And County V 18, County Roads B 54 And V 56, Twin Ponds Park, River Ranch Campground, Highway 18 And County V 56 and Highway 18 63 And County B 54. 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 ponding of water. Do not drive your vehicle through flooded roadways. && LAT...LON 4309 9208 4291 9208 4291 9255 4308 9255 TIME...MOT...LOC 1904Z 269DEG 32KT 4306 9253 4292 9243 HAIL THREAT...RADAR INDICATED MAX HAIL SIZE...<.75 IN WIND THREAT...RADAR INDICATED MAX WIND GUST...60 MPH $$ Kurz
873 WWUS53 KARX 241923 SVSARX Severe Weather Statement National Weather Service La Crosse WI 223 PM CDT Tue Aug 24 2021 IAC037-241930- /O.CON.KARX.SV.W.0088.000000T0000Z-210824T1930Z/ Chickasaw IA- 223 PM CDT Tue Aug 24 2021 ...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 230 PM CDT FOR SOUTHERN CHICKASAW COUNTY... At 222 PM CDT, severe thunderstorms were located along a line extending from near New Hampton to near Fredericksburg, moving east at 45 mph. HAZARD...60 mph wind gusts. SOURCE...Radar indicated. IMPACT...Expect damage to roofs, siding, and trees. Locations impacted include... New Hampton, Nashua, Fredericksburg, Lawler, Ionia, Chickasaw, Bassett, Bradford, Boyd, Williamstown, Republic, Highway 18 And County V 18, County Roads B 54 And V 56, Twin Ponds Park, River Ranch Campground, Highway 18 And County V 56 and Highway 18 63 And County B 54. PRECAUTIONARY/PREPAREDNESS ACTIONS... For your protection move to an interior room on the lowest floor of a building. Torrential rainfall is occurring with these storms, and may lead to flash flooding. Do not drive your vehicle through flooded roadways. && LAT...LON 4309 9208 4291 9208 4291 9255 4308 9255 TIME...MOT...LOC 1922Z 269DEG 39KT 4307 9224 4291 9221 HAIL THREAT...RADAR INDICATED MAX HAIL SIZE...<.75 IN WIND THREAT...RADAR INDICATED MAX WIND GUST...60 MPH $$ Kurz
The office that day
Everything else NWS La Crosse, WI issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 24, 12:35 PM CDT | Special Weather Statement | ARX | Mitchell | 55 min |
| Aug 24, 12:38 PM CDT | Special Weather Statement | ARX | Floyd | 67 min |
| Aug 24, 1:29 PM CDT | Special Weather Statement | ARX | Howard, Mitchell | 46 min |
| Aug 24, 1:48 PM CDT | Special Weather Statement | ARX | Chickasaw | 27 min |
| Aug 24, 2:15 PM CDT | Severe Thunderstorm Warning | ARX | Chickasaw, Fayette | 60 min |
| Aug 24, 2:59 PM CDT | Severe Thunderstorm Warning | ARX | Clayton, Fayette | 61 min |
| Aug 24, 3:12 PM CDT | Special Weather Statement | ARX | Fayette | 18 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.