Alert archive / Iowa / Severe Thunderstorm Warnings in 2021
Severe Thunderstorm Warning 101, NWS La Crosse, WI
NWS La Crosse, WI issued this severe thunderstorm warning at Sep 20, 2021, 4:25 PM CDT for 4 counties in Iowa. It was in force for 50 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
- Sep 20, 2021, 4:25 PM CDT (21:25 UTC)
- Expired
- Sep 20, 2021, 5:15 PM CDT
- In force
- 50 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, Howard County, IA, Mitchell County, IA
The radar
The La Crosse radar (KARX), 133 km from the middle of the area, began a volume at 21:28 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 |
|---|---|---|---|
| Sep 20, 4:31 PM CDT | TSTM WND DMG | Charles City, IA | 2 TO 4 INCH BRANCHES DOWN WITH A FEW UP TO 6 INCHES IN DIAMETER. |
| Sep 20, 4:31 PM CDT | TSTM WND GST 65 | Charles City, IA | WINDS ESTIMATED 60 TO 70 AT THE FIRE STATION. |
| Sep 20, 4:35 PM CDT | TSTM WND GST 40 | 3 E Charles City, IA | AWOS STATION KCCY CHARLES CITY AIRPORT. |
| Sep 20, 4:41 PM CDT | TSTM WND DMG | Bassett, IA | TREES DOWN. |
| Sep 20, 4:46 PM CDT | TSTM WND GST 36 | 4 W Saratoga, IA | MESONET STATION EW4652 RICEVILLE. |
| Sep 20, 4:50 PM CDT | TSTM WND GST 34 | 2 N Ionia, IA | MESONET STATION RNHI4 2 N IONIA. |
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 |
|---|---|---|---|
| Sep 20, 2:07 PM CDT | Severe Thunderstorm Watch | SPC | 7 hr |
The nearest sounding before it
Minneapolis, MN (KMPX), launched 12:00Z, 9.4 hours before the alert went out and 209 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
- 148 J/kg
- Mixed-layer CIN
- -141 J/kg
- Mixed-layer LCL
- 1002 m above ground
- 0-6 km bulk shear
- 37 kt
- 0-1 km storm-relative helicity
- 210 m²/s²
- 0-3 km storm-relative helicity
- 162 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 1.4
The text
As transmitted.
499
WUUS53 KARX 202125
SVRARX
IAC037-067-089-131-202215-
/O.NEW.KARX.SV.W.0101.210920T2125Z-210920T2215Z/
BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service La Crosse WI
425 PM CDT Mon Sep 20 2021
The National Weather Service in La Crosse has issued a
* Severe Thunderstorm Warning for...
Southeastern Mitchell County in north central Iowa...
Howard County in northeastern Iowa...
Floyd County in north central Iowa...
Chickasaw County in northeastern Iowa...
* Until 515 PM CDT.
* At 424 PM CDT, a severe thunderstorm was located near Charles City,
moving northeast at 50 mph.
HAZARD...60 mph wind gusts and penny size hail.
SOURCE...Radar indicated. Wind gusts of 40 to 50 mph have already
been reported with this storm.
IMPACT...Expect damage to roofs, siding, and trees.
* This severe thunderstorm will be near...
Floyd around 430 PM CDT.
Charles City around 435 PM CDT.
Elma around 455 PM CDT.
Jerico around 500 PM CDT.
Other locations impacted by this severe thunderstorm include Vernon
Springs, Idlewilde State Park, Bradford, Chickasaw, Roseville,
Oakwood and New Hampton Airport.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
For your protection move to an interior room on the lowest floor of a
building.
&&
LAT...LON 4348 9242 4334 9213 4301 9210 4290 9270
4291 9270 4291 9286 4306 9299
TIME...MOT...LOC 2124Z 236DEG 41KT 4303 9277
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...0.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH
$$
Skow4 follow-up statements
990
WWUS53 KARX 202135
SVSARX
Severe Weather Statement
National Weather Service La Crosse WI
435 PM CDT Mon Sep 20 2021
IAC037-067-089-131-202215-
/O.CON.KARX.SV.W.0101.000000T0000Z-210920T2215Z/
Mitchell IA-Howard IA-Floyd IA-Chickasaw IA-
435 PM CDT Mon Sep 20 2021
...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 515 PM CDT
FOR SOUTHEASTERN MITCHELL...HOWARD...EASTERN FLOYD AND CHICKASAW
COUNTIES...
At 435 PM CDT, a severe thunderstorm was located near Charles City,
moving northeast at 45 mph.
HAZARD...60 mph wind gusts and penny size hail.
SOURCE...Law enforcement.
IMPACT...Expect damage to roofs, siding, and trees.
This severe storm will be near...
Elma around 450 PM CDT.
Jerico around 500 PM CDT.
Other locations impacted by this severe thunderstorm include Vernon
Springs, Idlewilde State Park, Bradford, Chickasaw, Oakwood, New
Hampton Airport and Powersville.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
For your protection move to an interior room on the lowest floor of a
building.
&&
LAT...LON 4348 9242 4334 9213 4301 9210 4290 9270
4291 9270 4291 9273 4303 9280 4309 9291
TIME...MOT...LOC 2135Z 236DEG 41KT 4310 9262
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...0.75 IN
WIND THREAT...OBSERVED
MAX WIND GUST...60 MPH
$$
Skow991
WWUS53 KARX 202144
SVSARX
Severe Weather Statement
National Weather Service La Crosse WI
444 PM CDT Mon Sep 20 2021
IAC037-067-089-131-202215-
/O.CON.KARX.SV.W.0101.000000T0000Z-210920T2215Z/
Mitchell IA-Howard IA-Floyd IA-Chickasaw IA-
444 PM CDT Mon Sep 20 2021
...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 515 PM CDT
FOR SOUTHEASTERN MITCHELL...HOWARD...NORTHEASTERN FLOYD AND CHICKASAW
COUNTIES...
At 444 PM CDT, a severe thunderstorm was located near Elma, or 11
miles northeast of Charles City, moving northeast at 45 mph.
HAZARD...60 mph wind gusts and penny size hail.
SOURCE...Law enforcement.
IMPACT...Expect damage to roofs, siding, and trees.
This severe storm will be near...
Elma around 450 PM CDT.
Jerico around 500 PM CDT.
Other locations impacted by this severe thunderstorm include Vernon
Springs, Bradford, Chickasaw, New Hampton Airport, County Roads B 28
And V 18, Highway 18 And County V 18 and Colwell County Park.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
For your protection move to an interior room on the lowest floor of a
building.
&&
LAT...LON 4348 9242 4334 9213 4305 9210 4295 9258
4311 9266 4320 9276
TIME...MOT...LOC 2144Z 236DEG 41KT 4316 9250
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...0.75 IN
WIND THREAT...OBSERVED
MAX WIND GUST...60 MPH
$$
Skow985
WWUS53 KARX 202154
SVSARX
Severe Weather Statement
National Weather Service La Crosse WI
454 PM CDT Mon Sep 20 2021
IAC067-202203-
/O.CAN.KARX.SV.W.0101.000000T0000Z-210920T2215Z/
Floyd IA-
454 PM CDT Mon Sep 20 2021
...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN FLOYD COUNTY IS
CANCELLED...
The severe thunderstorm which prompted the warning has moved out of
the warned area. Therefore, the warning has been cancelled.
A Severe Thunderstorm Watch remains in effect until 1000 PM CDT for
north central and northeastern Iowa.
LAT...LON 4348 9242 4334 9213 4309 9210 4303 9242
4322 9254 4330 9262
TIME...MOT...LOC 2153Z 236DEG 41KT 4322 9237
$$
IAC037-089-131-202215-
/O.CON.KARX.SV.W.0101.000000T0000Z-210920T2215Z/
Mitchell IA-Howard IA-Chickasaw IA-
454 PM CDT Mon Sep 20 2021
...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 515 PM CDT
FOR EAST CENTRAL MITCHELL...HOWARD AND NORTHERN CHICKASAW COUNTIES...
At 453 PM CDT, a severe thunderstorm was located near Elma, or 11
miles north of New Hampton, moving northeast at 45 mph.
HAZARD...60 mph wind gusts and penny size hail.
SOURCE...Law enforcement.
IMPACT...Expect damage to roofs, siding, and trees.
This severe thunderstorm will remain over mainly rural areas of east
central Mitchell, Howard and northern Chickasaw Counties, including
the following locations... Lylahs Marsh County Park, Saratoga, County
B 17 And Bell Avenue, Maple Leaf, Vernon Springs, Hayden Prairie and
New Hampton Airport.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
For your protection move to an interior room on the lowest floor of a
building.
&&
LAT...LON 4348 9242 4334 9213 4309 9210 4303 9242
4322 9254 4330 9262
TIME...MOT...LOC 2153Z 236DEG 41KT 4322 9237
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...0.75 IN
WIND THREAT...OBSERVED
MAX WIND GUST...60 MPH
$$
Skow820
WWUS53 KARX 202207
SVSARX
Severe Weather Statement
National Weather Service La Crosse WI
507 PM CDT Mon Sep 20 2021
IAC037-089-131-202217-
/O.EXP.KARX.SV.W.0101.000000T0000Z-210920T2215Z/
Mitchell IA-Howard IA-Chickasaw IA-
507 PM CDT Mon Sep 20 2021
...THE SEVERE THUNDERSTORM WARNING FOR EAST CENTRAL MITCHELL...HOWARD
AND NORTHERN CHICKASAW COUNTIES WILL EXPIRE AT 515 PM CDT...
The storm which prompted the warning has weakened below severe
limits, and no longer poses an immediate threat to life or property.
Therefore, the warning will be allowed to expire. However gusty
winds and heavy rain are still possible with this thunderstorm.
A Severe Thunderstorm Watch remains in effect until 1000 PM CDT for
north central and northeastern Iowa.
LAT...LON 4348 9242 4334 9213 4309 9210 4303 9242
4322 9254 4330 9262
TIME...MOT...LOC 2207Z 236DEG 41KT 4331 9219
$$
SkowThe office that day
Everything else NWS La Crosse, WI issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Sep 20, 4:06 PM CDT | Special Weather Statement | ARX | Floyd | 24 min |
| Sep 20, 5:06 PM CDT | Special Weather Statement | ARX | Winneshiek | 24 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.