Alert archive / Iowa / Tornado Warnings in 2017

Tornado Warning 11, NWS La Crosse, WI

June 28, 2017Clayton County, Iowa

NWS La Crosse, WI issued this tornado warning at Jun 28, 2017, 4:49 PM CDT for Clayton County, Iowa. It was in force for 26 min. 3 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: Jun 28, 2017, 4:49 PM CDT (21:49 UTC)
Expired: Jun 28, 2017, 5:15 PM CDT
In force: 26 min
Issued by: NWS La Crosse, WI
Area: Storm-based polygon
Tornado: Radar indicated
Hail: 0.75 in

County Clayton County, IA

The radar

The La Crosse radar (KARX), 96 km from the middle of the area, began a volume at 21:50 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
Jun 28, 4:53 PM CDT	TSTM WND DMG	2 Nnw Farmersburg, IA	NUMEROUS TREES DOWN AT INTERSECTION OF 165TH STREET AND FALCON AVE. TIME ESTIMATED FROM RADAR.
Jun 28, 5:05 PM CDT	TSTM WND GST 60	1 E Farmersburg, IA	PEA SIZE HAIL ALSO.
Jun 28, 5:23 PM CDT	TSTM WND DMG	4 Sse Giard, IA	POWER LINES DOWN. 20-24 INCH TREE DOWN.

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
Jun 28, 2:53 PM CDT	Tornado Watch	SPC	9 hr

The nearest sounding before it

Davenport, (KDVN), launched 12:00Z, 9.8 hours before the alert went out and 161 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: 134 J/kg
Mixed-layer CIN: -204 J/kg
Mixed-layer LCL: 1152 m above ground
0-6 km bulk shear: 26 kt
0-1 km storm-relative helicity: 131 m²/s²
0-3 km storm-relative helicity: 217 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 2.3

Open this sounding in Storm Lab

The text

As transmitted.

800 
WFUS53 KARX 282149
TORARX
IAC043-282215-
/O.NEW.KARX.TO.W.0011.170628T2149Z-170628T2215Z/

BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service La Crosse WI
449 PM CDT WED JUN 28 2017

The National Weather Service in La Crosse has issued a

* Tornado Warning for...
  Northwestern Clayton County in northeastern Iowa...

* Until 515 PM CDT
    
* At 449 PM CDT, a severe thunderstorm capable of producing a tornado
  was located near Monona, or 10 miles north of Elkader, moving east
  at 45 mph.

  HAZARD...Tornado. 

  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...
  McGregor and Marquette around 510 PM CDT. 

Other locations impacted by this tornadic thunderstorm include Luana,
St. Olaf, Clayton, Spook Cave Campground and Giard.

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 4292 9155 4308 9154 4308 9118 4303 9117
      4299 9116 4298 9116 4296 9114 4294 9115
      4293 9114 4291 9114 4290 9112 4287 9110
TIME...MOT...LOC 2149Z 271DEG 38KT 4301 9144 

TORNADO...RADAR INDICATED
HAIL...<.75IN

$$

JAM

2 follow-up statements

694 
WWUS53 KARX 282158
SVSARX

Severe Weather Statement
National Weather Service La Crosse WI
458 PM CDT WED JUN 28 2017

IAC043-282215-
/O.CON.KARX.TO.W.0011.000000T0000Z-170628T2215Z/
Clayton IA-
458 PM CDT WED JUN 28 2017

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 515 PM CDT FOR
NORTHWESTERN CLAYTON COUNTY...
    
At 457 PM CDT, a severe thunderstorm capable of producing a tornado 
was located near Monona, or 11 miles west of Prairie Du Chien, 
moving east at 45 mph.

HAZARD...Tornado. 

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...
  Marquette and McGregor around 515 PM CDT. 

Other locations impacted by this tornadic thunderstorm include Luana,
Spook Cave Campground, Giard, National and Pikes Peak State Park.

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 4296 9147 4308 9147 4308 9118 4303 9117
      4299 9116 4298 9116 4295 9114 4294 9115
TIME...MOT...LOC 2157Z 259DEG 30KT 4302 9136 

TORNADO...RADAR INDICATED
HAIL...<.75IN

$$

JAM

033 
WWUS53 KARX 282212
SVSARX

Severe Weather Statement
National Weather Service La Crosse WI
512 PM CDT WED JUN 28 2017

IAC043-282221-
/O.EXP.KARX.TO.W.0011.000000T0000Z-170628T2215Z/
Clayton IA-
512 PM CDT WED JUN 28 2017

...THE TORNADO WARNING FOR NORTHWESTERN CLAYTON COUNTY WILL EXPIRE AT
515 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 tornado watch remains in effect until 1000 PM CDT for northeastern
Iowa...and southwestern Wisconsin.

LAT...LON 4296 9147 4308 9147 4308 9118 4303 9117
      4299 9116 4298 9116 4295 9114 4294 9115
TIME...MOT...LOC 2211Z 271DEG 38KT 4302 9117 

$$

JAM

The office that day

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

Issued	Product	Office	Counties	Lasted
Jun 28, 3:02 PM CDT	Special Weather Statement	ARX	Chickasaw, Floyd, Winneshiek	43 min
Jun 28, 3:38 PM CDT	Special Weather Statement	ARX	Allamakee, Chickasaw, Clayton, Fayette, Floyd	52 min
Jun 28, 3:52 PM CDT	Severe Thunderstorm Warning	ARX	Chickasaw, Fayette, Winneshiek	38 min
Jun 28, 4:34 PM CDT	Special Weather Statement	ARX	Clayton, Fayette	56 min
Jun 28, 5:11 PM CDT	Severe Thunderstorm Warning	ARX	Clayton	64 min
Jun 28, 5:36 PM CDT	Severe Thunderstorm Warning	ARX	Clayton	54 min
Jun 28, 5:51 PM CDT	Flash Flood Warning	ARX	Clayton, Fayette	3 hr
Jun 28, 6:04 PM CDT	Special Weather Statement	ARX	Clayton	26 min
Jun 28, 6:19 PM CDT	Severe Thunderstorm Warning	ARX	Clayton	26 min

Nearby

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