Alert archive / Iowa / Tornado Warnings in 2017

Tornado Warning 4, NWS La Crosse, WI

May 15, 2017Winneshiek County, Iowa

NWS La Crosse, WI issued this tornado warning at May 15, 2017, 6:46 PM CDT for Winneshiek County, Iowa. It was in force for 44 min. 16 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
May 15, 2017, 6:46 PM CDT (23:46 UTC)
Expired
May 15, 2017, 7:30 PM CDT
In force
44 min
Issued by
NWS La Crosse, WI
Area
Storm-based polygon
Tornado
Radar indicated
Hail
2.0 in

County Winneshiek County, IA

The radar

The La Crosse radar (KARX), 92 km from the middle of the area, began a volume at 23:48 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
May 15, 6:47 PM CDTTORNADO2 Wsw Calmar, IATREE DAMAGE EVIDENCE OF A BRIEF LOW-END EF0 TORNADO IN THE LAKE MEYER AREA AND ALONG 265TH AVE FURTHER WEST.
May 15, 6:53 PM CDTTSTM WND DMG3 Ne Festina, IAPOSSIBLE TORNADO. COMMODITY SHED COMPLETELY DESTROYED, 30 FT TRAVEL TRAILER TOSSED ACROSS LAWN, SEVERAL OTHER BUILDINGS DAMAGED, LARGE PINE TREE WAS TOPPED AND FOUND 1/4 OF A MILE TO THE EAST IN A FIELD. DAMAGE PATH WITH DEBRIS FROM LOCATION HEADING E/SE FROM
May 15, 6:54 PM CDTTSTM WND DMGSpillville, IALOTS OF TREE DAMAGE REPORTED
May 15, 6:54 PM CDTTSTM WND DMGSpillville, IALOTS OF TREE DAMAGE REPORTED.
May 15, 6:54 PM CDTHAIL 1.5Spillville, IA
May 15, 6:55 PM CDTHAIL 1Spillville, IA
May 15, 6:56 PM CDTTSTM WND DMGCalmar, IATREES DOWN
May 15, 6:56 PM CDTTSTM WND DMGCalmar, IATREES DOWN.
May 15, 6:56 PM CDTTSTM WND GST 82Calmar, IATIME ESTIMATED FROM RADAR.
May 15, 6:57 PM CDTTSTM WND DMGCalmar, IATREES DOWN. ONE BUILDING WITH SIDING DAMAGE.
May 15, 6:59 PM CDTHAIL 2Calmar, IA
May 15, 7:00 PM CDTTSTM WND DMG3 Ne Festina, IADELAYED REPORT. SHED DESTROYED, 30 FOOT TRAVEL TRAILER TOSSED ACROSS LAWN, PINE TREE TOPPED.
May 15, 7:10 PM CDTTSTM WND DMG3 S Frankville, IANUMEROUS TREES DOWN.
May 15, 7:10 PM CDTTSTM WND DMG3 Sse Frankville, IANUMEROUS TREES DOWN
May 15, 7:10 PM CDTTSTM WND DMGOssian, IAHIGHWAY 52 BLOCKED FROM DOWNED TREES IN OSSIAN
May 15, 7:10 PM CDTTSTM WND DMGOssian, IAHIGHWAY 52 BLOCKED FROM DOWNED TREES IN OSSIAN.

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.

IssuedProductOfficeLasted
May 15, 5:11 PM CDTSevere Thunderstorm WatchSPC9 hr

The nearest sounding before it

Davenport, (KDVN), launched 12:00Z, 11.8 hours before the alert went out and 204 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, Davenport, at 12:00Z on 2017-05-15Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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, Davenport, at 12:00Z on 2017-05-15The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 98 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1352 m above ground
0-6 km bulk shear
37 kt
0-1 km storm-relative helicity
98 m²/s²
0-3 km storm-relative helicity
158 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

451 
WFUS53 KARX 152346
TORARX
IAC191-160030-
/O.NEW.KARX.TO.W.0004.170515T2346Z-170516T0030Z/

BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service La Crosse WI
646 PM CDT MON MAY 15 2017

The National Weather Service in La Crosse has issued a

* Tornado Warning for...
  Southern Winneshiek County in northeastern Iowa...

* Until 730 PM CDT
    
* At 646 PM CDT, a severe thunderstorm capable of producing a tornado
  was located over Calmar, or 10 miles southwest of Decorah, moving
  east at 20 mph.

  HAZARD...Tornado and hail up to two inches in diameter. 

  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...
  Calmar around 655 PM CDT. 
  Ossian around 705 PM CDT. 

Other locations impacted by this tornadic thunderstorm include
Castalia, Festina, Nordness, Lake Meyer County Park and County Road W
46 And Centennial Road.

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.

&&

LAT...LON 4308 9202 4323 9202 4330 9160 4308 9161
TIME...MOT...LOC 2346Z 266DEG 19KT 4318 9191 

TORNADO...RADAR INDICATED
HAIL...2.00IN

$$

Wetenkamp
3 follow-up statements
017 
WWUS53 KARX 152355
SVSARX

Severe Weather Statement
National Weather Service La Crosse WI
655 PM CDT MON MAY 15 2017

IAC191-160030-
/O.CON.KARX.TO.W.0004.000000T0000Z-170516T0030Z/
Winneshiek IA-
655 PM CDT MON MAY 15 2017

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 730 PM CDT FOR
SOUTHEASTERN WINNESHIEK COUNTY...
    
At 654 PM CDT, a severe thunderstorm capable of producing a tornado
was located over Calmar, or 10 miles south of Decorah, moving east at
35 mph.

HAZARD...Tornado and two inch 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...
  Ossian around 700 PM CDT. 

Other locations impacted by this tornadic thunderstorm include
Castalia, Festina, Nordness, Lake Meyer County Park and County Road W
46 And Centennial Road.

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.

&&

LAT...LON 4308 9196 4324 9196 4330 9160 4308 9161
TIME...MOT...LOC 2354Z 286DEG 32KT 4316 9183 

TORNADO...RADAR INDICATED
HAIL...2.00IN

$$

Wetenkamp
903 
WWUS53 KARX 160004
SVSARX

Severe Weather Statement
National Weather Service La Crosse WI
704 PM CDT MON MAY 15 2017

IAC191-160030-
/O.CON.KARX.TO.W.0004.000000T0000Z-170516T0030Z/
Winneshiek IA-
704 PM CDT MON MAY 15 2017

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 730 PM CDT FOR
SOUTHEASTERN WINNESHIEK COUNTY...
    
At 703 PM CDT, a severe thunderstorm capable of producing a tornado
was located near Ossian, or 12 miles south of Decorah, moving east at
50 mph.

HAZARD...Tornado and two inch 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 tornadic thunderstorm will remain over mainly rural areas of
southeastern Winneshiek County, including the following locations:
Castalia, Festina, Frankville and County Road W 46 And Centennial
Road.

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.

&&

LAT...LON 4308 9188 4320 9186 4320 9161 4308 9161
TIME...MOT...LOC 0003Z 280DEG 43KT 4313 9171 

TORNADO...RADAR INDICATED
HAIL...2.00IN

$$

Wetenkamp
936 
WWUS53 KARX 160021
SVSARX

Severe Weather Statement
National Weather Service La Crosse WI
721 PM CDT MON MAY 15 2017

IAC191-160030-
/O.EXP.KARX.TO.W.0004.000000T0000Z-170516T0030Z/
Winneshiek IA-
721 PM CDT MON MAY 15 2017

...THE TORNADO WARNING FOR SOUTHEASTERN WINNESHIEK COUNTY WILL EXPIRE
AT 730 PM CDT...
    
The tornado threat has diminished and the Tornado Warning has been
cancelled. However, large hail and damaging winds remain likely and a
Severe Thunderstorm Warning remains in effect for the area.

A severe thunderstorm watch remains in effect until 100 AM CDT for
northeastern Iowa.

LAT...LON 4308 9188 4320 9186 4320 9161 4308 9161
TIME...MOT...LOC 0020Z 266DEG 19KT 4314 9159 

$$

Wetenkamp

The office that day

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

IssuedProductOfficeCountiesLasted
May 15, 3:50 PM CDTSpecial Weather StatementARXMitchell55 min
May 15, 5:22 PM CDTSpecial Weather StatementARXFloyd, Mitchell23 min
May 15, 5:40 PM CDTSevere Thunderstorm WarningARXChickasaw, Floyd, Howard, Mitchell65 min
May 15, 5:55 PM CDTSevere Thunderstorm WarningARXWinneshiek50 min
May 15, 6:40 PM CDTSevere Thunderstorm WarningARXAllamakee, Chickasaw, Fayette, Winneshiek65 min

Nearby

Tornado Warnings in Iowa, 2017Every tornado warning in 2017Tornadoes in 2017

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.