Alert archive / Iowa / Tornado Warnings in 2016

Tornado Warning 14, NWS La Crosse, WI

September 21, 2016Floyd County, Iowa

NWS La Crosse, WI issued this tornado warning at Sep 21, 2016, 7:34 PM CDT for Floyd County, Iowa. It was in force for 41 min. 2 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 21, 2016, 7:34 PM CDT (00:34 UTC)
Expired
Sep 21, 2016, 8:15 PM CDT
In force
41 min
Issued by
NWS La Crosse, WI
Area
Storm-based polygon
Tornado
Radar indicated
Hail
1.5 in

County Floyd County, IA

The radar

The Des Moines radar (KDMX), 156 km from the middle of the area, began a volume at 00:33 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
Sep 21, 7:44 PM CDTTSTM WND GST 601 W Marble Rock, IA.
Sep 21, 7:44 PM CDTTSTM WND GST 701 Ene Marble Rock, IA.

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 00:00Z, 0.6 hours before the alert went out and 218 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, Minneapolis, MN at 00:00Z on 2016-09-22Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 144 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, Minneapolis, MN at 00:00Z on 2016-09-22The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 428 square meters per square second.193958Sfc1 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
144 J/kg
Mixed-layer CIN
-361 J/kg
Mixed-layer LCL
641 m above ground
0-6 km bulk shear
34 kt
0-1 km storm-relative helicity
428 m²/s²
0-3 km storm-relative helicity
596 m²/s²
Significant tornado parameter
0.0
Supercell composite
11.6

Open this sounding in Storm Lab

The text

As transmitted.

952 
WFUS53 KARX 220034
TORARX
IAC067-220115-
/O.NEW.KARX.TO.W.0014.160922T0034Z-160922T0115Z/

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE LA CROSSE WI
734 PM CDT WED SEP 21 2016

THE NATIONAL WEATHER SERVICE IN LA CROSSE HAS ISSUED A

* TORNADO WARNING FOR...
  SOUTHERN FLOYD COUNTY IN NORTH CENTRAL IOWA...

* UNTIL 815 PM CDT
    
* AT 733 PM CDT...A SEVERE THUNDERSTORM CAPABLE OF PRODUCING A
  TORNADO WAS LOCATED 2 MILES SOUTHWEST OF MARBLE ROCK...OR 12 MILES
  NORTH OF ALLISON...MOVING SOUTHEAST AT 25 MPH.

  HAZARD...TORNADO AND PING PONG BALL 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...
  POWERSVILLE AROUND 810 PM CDT. 

OTHER LOCATIONS IMPACTED BY THIS TORNADIC THUNDERSTORM INCLUDE RURAL
AREAS ALONG THE FLOYD AND BUTLER COUNTY LINE.

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.

HEAVY RAINFALL MAY HIDE THIS TORNADO. DO NOT WAIT TO SEE OR HEAR THE
TORNADO. TAKE COVER NOW!

&&

LAT...LON 4304 9302 4294 9255 4291 9255 4291 9302
TIME...MOT...LOC 0033Z 293DEG 20KT 4292 9286 

TORNADO...RADAR INDICATED
HAIL...1.50IN

$$

AJ
2 follow-up statements
270 
WWUS53 KARX 220056
SVSARX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE LA CROSSE WI
756 PM CDT WED SEP 21 2016

IAC067-220115-
/O.CON.KARX.TO.W.0014.000000T0000Z-160922T0115Z/
FLOYD IA-
756 PM CDT WED SEP 21 2016

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 815 PM CDT FOR SOUTHERN
FLOYD COUNTY...
    
AT 755 PM CDT...A SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO
WAS LOCATED NEAR GREENE...OR 10 MILES SOUTH OF CHARLES CITY...MOVING
EAST AT 30 MPH.

HAZARD...TORNADO AND PING PONG BALL 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...
  POWERSVILLE AROUND 810 PM CDT. 

OTHER LOCATIONS IMPACTED BY THIS TORNADIC THUNDERSTORM INCLUDE
RURAL AREAS ALONG THE FLOYD AND BUTLER COUNTY LINE.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

HEAVY RAINFALL MAY HIDE THIS TORNADO. DO NOT WAIT TO SEE OR HEAR THE
TORNADO. TAKE COVER NOW!

&&

LAT...LON 4304 9302 4294 9255 4291 9255 4291 9302
TIME...MOT...LOC 0055Z 273DEG 24KT 4291 9268 

TORNADO...RADAR INDICATED
HAIL...1.50IN

$$

AJ
940 
WWUS53 KARX 220114
SVSARX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE LA CROSSE WI
814 PM CDT WED SEP 21 2016

IAC067-220122-
/O.EXP.KARX.TO.W.0014.000000T0000Z-160922T0115Z/
FLOYD IA-
814 PM CDT WED SEP 21 2016

...THE TORNADO WARNING FOR SOUTHERN FLOYD COUNTY WILL EXPIRE AT 815
PM CDT...
        
THE STORM WHICH PROMPTED THE WARNING HAS MOVED OUT OF THE AREA.
THEREFORE THE WARNING WILL BE ALLOWED TO EXPIRE. HOWEVER...FLASH
FLOODING REMAINS A SIGNIFICANT CONCERN AND A FLASH FLOOD WARNING
REMAINS IN EFFECT THROUGH 4 AM.

LAT...LON 4304 9302 4294 9255 4291 9255 4291 9302
TIME...MOT...LOC 0112Z 293DEG 20KT 4287 9256 

$$

AJ

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 21, 7:05 PM CDTFlash Flood WarningARXChickasaw5 hr
Sep 21, 7:11 PM CDTSevere Thunderstorm WarningARXFloyd49 min
Sep 21, 8:11 PM CDTFlash Flood Warning EmergencyARXFloyd8 hr
Sep 21, 8:44 PM CDTSpecial Weather StatementARXAllamakee, Winneshiek46 min
Sep 21, 9:19 PM CDTSpecial Weather StatementARXClayton, Fayette56 min
Sep 21, 10:13 PM CDTSpecial Weather StatementARXClayton, Fayette62 min
Sep 22, 12:04 AM CDTFlash Flood WarningARXChickasaw4 hr
Sep 22, 12:13 AM CDTSpecial Weather StatementARXAllamakee, Chickasaw, Floyd, Howard, Mitchell, Winneshiek2 hr
Sep 22, 12:48 AM CDTFlash Flood WarningARXAllamakee6 hr
Sep 22, 1:00 AM CDTFlash Flood WarningARXHoward, Mitchell, Winneshiek6 hr
Sep 22, 2:20 AM CDTFlash Flood WarningARXChickasaw, Fayette, Floyd6 hr
Sep 22, 3:55 AM CDTFlash Flood Warning EmergencyARXChickasaw, Floyd4 hr
Sep 22, 4:09 AM CDTFlash Flood WarningARXClayton6 hr
Sep 22, 4:53 AM CDTRiver Flood WarningARXMitchell3 days
Sep 22, 4:53 AM CDTRiver Flood WarningARXFloyd4 days
Sep 22, 5:39 AM CDTRiver Flood WarningARXAllamakee70 hr
Sep 22, 6:51 AM CDTFlash Flood WarningARXAllamakee3 hr
Sep 22, 7:00 AM CDTAreal Flood WarningARXHoward, Mitchell, Winneshiek6 hr
Sep 22, 8:02 AM CDTFlash Flood WarningARXChickasaw, Fayette, Floyd5 hr
Sep 22, 9:00 AM CDTRiver Flood WarningARXClayton5 days
Sep 22, 9:00 AM CDTRiver Flood WarningARXClayton4 days
Sep 22, 9:38 AM CDTFlash Flood WarningARXAllamakee3 hr
Sep 22, 10:19 AM CDTFlash Flood WarningARXClayton3 hr
Sep 22, 11:20 AM CDTRiver Flood WarningARXAllamakee, Clayton10 days
Sep 22, 11:20 AM CDTRiver Flood WarningARXClayton9 days
Sep 22, 12:58 PM CDTAreal Flood WarningARXAllamakee, Chickasaw, Clayton, Fayette, Floyd, Howard and 2 more21 hr

Nearby

Tornado Warnings in Iowa, 2016Every tornado warning in 2016Tornadoes in 2016

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.