Alert archive / Iowa / Tornado Warnings in 2021

Tornado Warning 13, NWS La Crosse, WI

August 27, 2021Floyd County, Iowa

NWS La Crosse, WI issued this tornado warning at Aug 27, 2021, 5:34 PM CDT for Floyd County, Iowa. It was in force for 41 min. 4 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 27, 2021, 5:34 PM CDT (22:34 UTC)
Expired: Aug 27, 2021, 6:15 PM CDT
In force: 41 min
Issued by: NWS La Crosse, WI
Area: Storm-based polygon
Tornado: Radar indicated
Hail: 1.0 in

County Floyd County, IA

The radar

The Des Moines radar (KDMX), 157 km from the middle of the area, began a volume at 22:38 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 27, 5:56 PM CDT	TORNADO	2 W Marble Rock, IA
Aug 27, 6:00 PM CDT	TORNADO	1 S Marble Rock, IA	DAMAGE IS EXTENSIVE SOUTH TO EAST-NORTHEAST OF MARBLE ROCK.
Aug 27, 6:09 PM CDT	TORNADO	4 Sw Charles City, IA
Aug 27, 6:10 PM CDT	TORNADO	2 Se Marble Rock, IA	LARGE ABOVE GROUND PROPANE TANKS WERE KNOCKED OVER BY A TORNADO.

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 27, 5:15 PM CDT	Tornado Watch	SPC	6 hr

The nearest sounding before it

Minneapolis, MN (KMPX), launched 12:00Z, 10.6 hours before the alert went out and 213 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: 487 J/kg
Mixed-layer CIN: -63 J/kg
Mixed-layer LCL: 644 m above ground
0-6 km bulk shear: 24 kt
0-1 km storm-relative helicity: -9 m²/s²
0-3 km storm-relative helicity: -16 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

032 
WFUS53 KARX 272234
TORARX
IAC067-272315-
/O.NEW.KARX.TO.W.0013.210827T2234Z-210827T2315Z/

BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service La Crosse WI
534 PM CDT Fri Aug 27 2021

The National Weather Service in La Crosse has issued a

* Tornado Warning for...
  Southwestern Floyd County in north central Iowa...

* Until 615 PM CDT.
    
* At 534 PM CDT, a severe thunderstorm capable of producing a tornado
  was located near Rockwell, or 14 miles north of Hampton, moving
  east at 25 mph.

  HAZARD...Tornado and quarter size hail.

  SOURCE...Radar indicated rotation.

  IMPACT...Flying debris will be dangerous to those caught without 
           shelter. Mobile homes will be damaged or destroyed. 
           Damage to roofs, windows, and vehicles will occur.  Tree 
           damage is likely.

* This dangerous storm will be near...
  Rockford around 555 PM CDT.
  Marble Rock around 600 PM CDT.

Other locations impacted by this tornadic thunderstorm include
Highway 14 And County Road B 60, County Roads B 60 And T 18,
Roseville, County Roads 147 And T 34, Oakwood, Floyd Crossing and
Powersville.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW! Move to a basement or an interior room on the lowest
floor of a sturdy building. Avoid windows. If you are outdoors, in a
mobile home, or in a vehicle, move to the closest substantial shelter
and protect yourself from flying debris.

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

&&

LAT...LON 4305 9302 4309 9269 4291 9267 4291 9303
TIME...MOT...LOC 2234Z 264DEG 24KT 4294 9310 

TORNADO...RADAR INDICATED
MAX HAIL SIZE...1.00 IN

$$

Skow

4 follow-up statements

417 
WWUS53 KARX 272241
SVSARX

Severe Weather Statement
National Weather Service La Crosse WI
541 PM CDT Fri Aug 27 2021

IAC067-272315-
/O.CON.KARX.TO.W.0013.000000T0000Z-210827T2315Z/
Floyd IA-
541 PM CDT Fri Aug 27 2021

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 615 PM CDT FOR
SOUTHWESTERN FLOYD COUNTY...
        
At 541 PM CDT, a severe thunderstorm capable of producing a tornado
was located 8 miles west of Marble Rock, or 16 miles southeast of
Mason City, moving east at 30 mph.

HAZARD...Tornado and quarter size hail.

SOURCE...Weather spotters reported a funnel cloud.

IMPACT...Flying debris will be dangerous to those caught without 
         shelter. Mobile homes will be damaged or destroyed. Damage 
         to roofs, windows, and vehicles will occur.  Tree damage is 
         likely.

This dangerous storm will be near...
  Rockford around 550 PM CDT.
  Marble Rock around 600 PM CDT.
  Charles City around 625 PM CDT.

Other locations impacted by this tornadic thunderstorm include
Highway 14 And County Road B 60, County Roads B 60 And T 18,
Roseville, County Roads 147 And T 34, Oakwood, Floyd Crossing and
Powersville.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW! Move to a basement or an interior room on the lowest
floor of a sturdy building. Avoid windows. If you are outdoors, in a
mobile home, or in a vehicle, move to the closest substantial shelter
and protect yourself from flying debris.

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

&&

LAT...LON 4305 9302 4309 9269 4291 9267 4291 9303
TIME...MOT...LOC 2241Z 264DEG 24KT 4295 9303 

TORNADO...RADAR INDICATED
MAX HAIL SIZE...1.00 IN

$$

Skow

649 
WWUS53 KARX 272252
SVSARX

Severe Weather Statement
National Weather Service La Crosse WI
552 PM CDT Fri Aug 27 2021

IAC067-272315-
/O.CON.KARX.TO.W.0013.000000T0000Z-210827T2315Z/
Floyd IA-
552 PM CDT Fri Aug 27 2021

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 615 PM CDT FOR
SOUTHWESTERN FLOYD COUNTY...
        
At 552 PM CDT, a severe thunderstorm capable of producing a tornado
was located near Marble Rock, or 16 miles southwest of Charles City,
moving east at 25 mph.

HAZARD...Tornado and quarter size hail.

SOURCE...Weather spotters reported a funnel cloud.

IMPACT...Flying debris will be dangerous to those caught without 
         shelter. Mobile homes will be damaged or destroyed. Damage 
         to roofs, windows, and vehicles will occur.  Tree damage is 
         likely.

This dangerous storm will be near...
  Rockford around 555 PM CDT.
  Marble Rock around 605 PM CDT.
  Charles City around 630 PM CDT.

Other locations impacted by this tornadic thunderstorm include
Highway 14 And County Road B 60, County Roads B 60 And T 18,
Roseville, County Roads 147 And T 34, Oakwood, Floyd Crossing and
Powersville.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW! Move to a basement or an interior room on the lowest
floor of a sturdy building. Avoid windows. If you are outdoors, in a
mobile home, or in a vehicle, move to the closest substantial shelter
and protect yourself from flying debris.

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

&&

LAT...LON 4305 9302 4309 9269 4291 9267 4291 9303
TIME...MOT...LOC 2252Z 263DEG 22KT 4296 9297 

TORNADO...RADAR INDICATED
MAX HAIL SIZE...1.00 IN

$$

Skow

544 
WWUS53 KARX 272257 CCA
SVSARX

Severe Weather Statement
National Weather Service La Crosse WI
557 PM CDT Fri Aug 27 2021

IAC067-272315-
/O.COR.KARX.TO.W.0013.000000T0000Z-210827T2315Z/
Floyd IA-
557 PM CDT Fri Aug 27 2021

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 615 PM CDT FOR
SOUTHWESTERN FLOYD COUNTY...
    
At 556 PM CDT, a confirmed tornado was located near Marble Rock, or
15 miles southwest of Charles City, moving east at 25 mph.

HAZARD...Damaging tornado and quarter size hail.

SOURCE...Weather spotters confirmed tornado.

IMPACT...Flying debris will be dangerous to those caught without 
         shelter. Mobile homes will be damaged or destroyed. Damage 
         to roofs, windows, and vehicles will occur.  Tree damage is 
         likely.

This tornado will be near...
  Marble Rock around 605 PM CDT.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

To repeat, a tornado is on the ground. TAKE COVER NOW! Move to a
basement or an interior room on the lowest floor of a sturdy
building. Avoid windows. If you are outdoors, in a mobile home, or in
a vehicle, move to the closest substantial shelter and protect
yourself from flying debris.

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

&&

LAT...LON 4305 9302 4309 9269 4291 9267 4291 9303
TIME...MOT...LOC 2252Z 263DEG 22KT 4296 9297 

TORNADO...OBSERVED
MAX HAIL SIZE...1.00 IN

$$

Skow

375 
WWUS53 KARX 272304
SVSARX

Severe Weather Statement
National Weather Service La Crosse WI
604 PM CDT Fri Aug 27 2021

IAC067-272315-
/O.CON.KARX.TO.W.0013.000000T0000Z-210827T2315Z/
Floyd IA-
604 PM CDT Fri Aug 27 2021

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 615 PM CDT FOR
SOUTHWESTERN FLOYD COUNTY...
    
At 604 PM CDT, a confirmed tornado was located over Marble Rock, or
10 miles southwest of Charles City, moving east at 25 mph.

HAZARD...Damaging tornado and quarter size hail.

SOURCE...Weather spotters confirmed a brief tornado.

IMPACT...Flying debris will be dangerous to those caught without 
         shelter. Mobile homes will be damaged or destroyed. Damage 
         to roofs, windows, and vehicles will occur.  Tree damage is 
         likely.

This tornado will be near...
  Charles City around 625 PM CDT.

Other locations impacted by this tornadic thunderstorm include
Highway 14 And County Road B 60, Oakwood, Powersville and Roseville.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

To repeat, a tornado is on the ground. TAKE COVER NOW! Move to a
basement or an interior room on the lowest floor of a sturdy
building. Avoid windows. If you are outdoors, in a mobile home, or in
a vehicle, move to the closest substantial shelter and protect
yourself from flying debris.

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

&&

LAT...LON 4302 9296 4308 9269 4291 9267 4291 9295
TIME...MOT...LOC 2304Z 264DEG 23KT 4296 9284 

TORNADO...OBSERVED
MAX HAIL SIZE...1.00 IN

$$

Skow

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 27, 1:51 AM CDT	Flash Flood Warning	ARX	Howard, Mitchell	4 hr
Aug 27, 3:33 AM CDT	Flash Flood Warning	ARX	Howard, Mitchell, Winneshiek	4 hr
Aug 27, 9:42 AM CDT	River Flood Warning	ARX	Winneshiek	60 hr
Aug 27, 3:24 PM CDT	Special Weather Statement	ARX	Howard, Mitchell	51 min
Aug 27, 6:09 PM CDT	Tornado Warning Tornado observed	ARX	Chickasaw, Floyd	51 min
Aug 27, 6:45 PM CDT	Tornado Warning Tornado observed	ARX	Chickasaw, Fayette	45 min
Aug 27, 6:52 PM CDT	Severe Thunderstorm Warning	ARX	Allamakee, Fayette, Winneshiek	38 min

Nearby

Tornado Warnings in Iowa, 2021 Every tornado warning in 2021 Tornadoes 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.