Alert archive / Iowa / Tornado Warnings in 2017

Tornado Warning 24, NWS La Crosse, WI

July 19, 2017Clayton County, Iowa

NWS La Crosse, WI issued this tornado warning at Jul 19, 2017, 5:54 PM CDT for Clayton County, Iowa. It was in force for 24 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: Jul 19, 2017, 5:54 PM CDT (22:54 UTC)
Expired: Jul 19, 2017, 6:18 PM CDT
In force: 24 min
Issued by: NWS La Crosse, WI
Area: Storm-based polygon
Tornado: Radar indicated
Hail: 0.0 in

County Clayton County, IA

The radar

The La Crosse radar (KARX), 96 km from the middle of the area, began a volume at 22:53 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
Jul 19, 6:03 PM CDT	TSTM WND DMG	Monona, IA	LOTS OF TREES AND POWER LINES DOWN. CORN ALSO IMPACTED. DAMAGE CONTINUED TOWARD MCGREGOR.
Jul 19, 6:16 PM CDT	TORNADO 1	Mcgregor, IA	* 2 INJ * EF1 TORNADO PATH IDENTIFIED FROM 5W MCGREGOR TO MCGREGOR IA. 608-616 PM. 2 MINOR INJURIES.

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
Jul 19, 3:29 PM CDT	Severe Thunderstorm Watch	SPC	6 hr

The nearest sounding before it

Davenport, (KDVN), launched 12:00Z, 10.9 hours before the alert went out and 164 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: 147 J/kg
Mixed-layer CIN: -138 J/kg
Mixed-layer LCL: 1286 m above ground
0-6 km bulk shear: 25 kt
0-1 km storm-relative helicity: 56 m²/s²
0-3 km storm-relative helicity: 96 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.2

Open this sounding in Storm Lab

The text

As transmitted.

774 
WFUS53 KARX 192254
TORARX
IAC043-192330-
/O.NEW.KARX.TO.W.0024.170719T2254Z-170719T2330Z/

BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service La Crosse WI
554 PM CDT WED JUL 19 2017

The National Weather Service in La Crosse has issued a

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

* Until 630 PM CDT

* At 554 PM CDT, severe thunderstorms capable of producing both
  tornadoes and extensive straight line wind damage were located near
  Clermont, or 12 miles east of West Union, moving east at 70 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. 

* These dangerous storms will be near...
  Monona around 600 PM CDT. 
  Farmersburg around 605 PM CDT. 
  McGregor and Marquette around 610 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.

This cluster of thunderstorms is capable of producing tornadoes and
widespread significant wind damage. Do not wait to see or hear the
tornado. For your protection move to an interior room on the lowest
floor of a building.

&&

LAT...LON 4293 9161 4308 9161 4308 9118 4298 9116
      4296 9114 4294 9115 4291 9114 4290 9113
TIME...MOT...LOC 2254Z 275DEG 63KT 4300 9157 

TORNADO...RADAR INDICATED
HAIL...0.00IN

$$

RRS

3 follow-up statements

431 
WWUS53 KARX 192303
SVSARX

Severe Weather Statement
National Weather Service La Crosse WI
603 PM CDT WED JUL 19 2017

IAC043-192330-
/O.CON.KARX.TO.W.0024.000000T0000Z-170719T2330Z/
Clayton IA-
603 PM CDT WED JUL 19 2017

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 630 PM CDT FOR
NORTHWESTERN CLAYTON COUNTY...
    
At 603 PM CDT, a severe thunderstorm capable of producing a tornado
was located near Farmersburg, or 10 miles north of Elkader, moving
east at 65 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 615 PM CDT. 

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

PRECAUTIONARY/PREPAREDNESS ACTIONS...

This cluster of thunderstorms is capable of producing tornadoes and 
widespread significant wind damage. Do not wait to see or hear the 
tornado. For your protection move to an interior room on the lowest 
floor of a building.

&&

LAT...LON 4295 9148 4308 9150 4308 9118 4298 9116
      4296 9114 4294 9115 4293 9115 4292 9114
TIME...MOT...LOC 2303Z 270DEG 58KT 4300 9138 

TORNADO...RADAR INDICATED
HAIL...0.00IN

$$

RRS

502 
WWUS53 KARX 192310
SVSARX

Severe Weather Statement
National Weather Service La Crosse WI
610 PM CDT WED JUL 19 2017

IAC043-192330-
/O.CON.KARX.TO.W.0024.000000T0000Z-170719T2330Z/
Clayton IA-
610 PM CDT WED JUL 19 2017

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 630 PM CDT FOR NORTH
CENTRAL CLAYTON COUNTY...
    
At 610 PM CDT, a severe thunderstorm capable of producing a tornado
was located near McGregor, or near Prairie Du Chien, moving east at
55 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 tornadic thunderstorm will remain over mainly rural areas of
north central Clayton County, including the following locations:
Froelich, Spook Cave Campground, Giard, National and Beula.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If a tornado or other severe weather is spotted, report it to the
National Weather Service or your local nearest law enforcement agency
who will send your report. This act may save lives of others in the
path of dangerous weather.

&&

LAT...LON 4295 9134 4308 9140 4308 9118 4298 9116
      4296 9114 4294 9115
TIME...MOT...LOC 2310Z 261DEG 49KT 4302 9127 

TORNADO...RADAR INDICATED
HAIL...0.00IN

$$

RRS

576 
WWUS53 KARX 192318
SVSARX

Severe Weather Statement
National Weather Service La Crosse WI
618 PM CDT WED JUL 19 2017

IAC043-192328-
/O.CAN.KARX.TO.W.0024.000000T0000Z-170719T2330Z/
Clayton IA-
618 PM CDT WED JUL 19 2017

...THE TORNADO WARNING FOR NORTH CENTRAL CLAYTON COUNTY IS
CANCELLED...
    
The tornado threat has diminished and the Tornado Warning has been 
cancelled. However, damaging winds remain likely and a Severe 
Thunderstorm Warning remains in effect for the area.

A severe thunderstorm watch remains in effect until 900 PM CDT for
northeastern Iowa...and southwestern Wisconsin.

LAT...LON 4295 9134 4308 9140 4308 9118 4298 9116
      4296 9114 4294 9115
TIME...MOT...LOC 2316Z 275DEG 63KT 4301 9107 

$$

RRS

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 19, 4:04 PM CDT	Special Weather Statement	ARX	Chickasaw, Floyd, Howard, Mitchell	86 min
Jul 19, 4:25 PM CDT	Severe Thunderstorm Warning	ARX	Floyd, Mitchell	65 min
Jul 19, 4:57 PM CDT	Severe Thunderstorm Warning	ARX	Chickasaw, Howard, Winneshiek	63 min
Jul 19, 5:04 PM CDT	Tornado Warning	ARX	Mitchell	10 min
Jul 19, 5:13 PM CDT	Tornado Warning	ARX	Howard	32 min
Jul 19, 5:19 PM CDT	Tornado Warning	ARX	Howard	10 min
Jul 19, 5:25 PM CDT	Severe Thunderstorm Warning	ARX	Allamakee, Clayton, Fayette, Winneshiek	80 min
Jul 19, 5:44 PM CDT	Tornado Warning	ARX	Winneshiek	13 min
Jul 19, 5:47 PM CDT	Tornado Warning	ARX	Fayette	11 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.