Alert archive / Iowa / Severe Thunderstorm Warnings in 2016

Severe Thunderstorm Warning 69, NWS La Crosse, WI

August 4, 2016Clayton County, Fayette County, Iowa

NWS La Crosse, WI issued this severe thunderstorm warning at Aug 4, 2016, 6:46 PM CDT for Clayton County, Fayette County, Iowa. It was in force for 44 min. 7 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 4, 2016, 6:46 PM CDT (23:46 UTC)
Expired: Aug 4, 2016, 7:30 PM CDT
In force: 44 min
Issued by: NWS La Crosse, WI
Area: Storm-based polygon
Hail: 0.75 in
Wind: 60.0 mph

Counties Clayton County, IA, Fayette County, IA

The radar

The La Crosse radar (KARX), 114 km from the middle of the area, began a volume at 23:45 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 4, 6:49 PM CDT	TSTM WND GST 50	4 W Stanley, IA	REPORTED WINDS SUSTAINED OF 40 MPH WITH GUSTS OVER 50 MPH.
Aug 4, 7:02 PM CDT	TSTM WND DMG	2 S Clayton, IA	TREE DOWN NEAR GREAT RIVER ROAD. TIME ESTIMATED FROM RADAR.
Aug 4, 7:05 PM CDT	TSTM WND GST 43	1 S Bixby State Park, IA
Aug 4, 7:05 PM CDT	TSTM WND GST 43	Edgewood, IA
Aug 4, 7:18 PM CDT	TSTM WND DMG	Colesburg, IA	PART OF A STEEL ROOF BLOWN OFF A BUILDING ACROSS FROM THE FIRE DEPARTMENT.
Aug 4, 7:19 PM CDT	TSTM WND DMG	Colesburg, IA	SEVERAL LARGE TREE BRANCHES DOWN...TWO OF WHICH CAUSED DAMAGE TO ROOFS. POWER OUT THROUGH OUT TOWN.
Aug 4, 7:19 PM CDT	TSTM WND DMG	Colesburg, IA	1 FOOT DIAMATER BRANCH FROM A 40 YEAR OLD MAPLE TREE BROKEN OFF.

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 4, 4:44 PM CDT	Severe Thunderstorm Watch	SPC	6 hr

The nearest sounding before it

Davenport, (KDVN), launched 12:00Z, 11.8 hours before the alert went out and 156 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: 500 J/kg
Mixed-layer CIN: -126 J/kg
Mixed-layer LCL: 970 m above ground
0-6 km bulk shear: 16 kt
0-1 km storm-relative helicity: 10 m²/s²
0-3 km storm-relative helicity: 98 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

656 
WUUS53 KARX 042346
SVRARX
IAC043-065-050030-
/O.NEW.KARX.SV.W.0069.160804T2346Z-160805T0030Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE LA CROSSE WI
646 PM CDT THU AUG 4 2016

THE NATIONAL WEATHER SERVICE IN LA CROSSE HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  CLAYTON COUNTY IN NORTHEASTERN IOWA...
  SOUTHEASTERN FAYETTE COUNTY IN NORTHEASTERN IOWA...

* UNTIL 730 PM CDT

* AT 645 PM CDT...SEVERE THUNDERSTORMS WERE LOCATED ALONG A LINE
  EXTENDING FROM NEAR POSTVILLE TO STANLEY...MOVING EAST AT 35 MPH.

  HAZARD...60 MPH WIND GUSTS. 

  SOURCE...RADAR INDICATED. 

  IMPACT...EXPECT DAMAGE TO ROOFS...SIDING...AND TREES. 

* SEVERE THUNDERSTORMS WILL BE NEAR...
  MONONA AND FARMERSBURG AROUND 655 PM CDT. 
  STRAWBERRY POINT AROUND 705 PM CDT. 
  MARQUETTE AND MCGREGOR AROUND 710 PM CDT. 
  EDGEWOOD AROUND 720 PM CDT. 

OTHER LOCATIONS IMPACTED BY THESE SEVERE THUNDERSTORMS INCLUDE
LUANA... WADENA...ST. OLAF...GARBER AND OSTERDOCK.

PEOPLE ATTENDING THE CLAYTON COUNTY FAIR SHOULD SEEK SAFE SHELTER
IMMEDIATELY!

PRECAUTIONARY/PREPAREDNESS ACTIONS...

FOR YOUR PROTECTION MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR OF A
BUILDING.

&&

LAT...LON 4264 9189 4265 9189 4308 9160 4308 9118
      4291 9114 4290 9113 4264 9116
TIME...MOT...LOC 2345Z 277DEG 33KT 4310 9148 4262 9181 

HAIL...<.75IN
WIND...60MPH
 
$$

DAB

2 follow-up statements

921 
WWUS53 KARX 050002
SVSARX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE LA CROSSE WI
702 PM CDT THU AUG 4 2016

IAC043-065-050030-
/O.CON.KARX.SV.W.0069.000000T0000Z-160805T0030Z/
CLAYTON IA-FAYETTE IA-
702 PM CDT THU AUG 4 2016

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 730 PM CDT
FOR CLAYTON AND SOUTHEASTERN FAYETTE COUNTIES...

AT 701 PM CDT...SEVERE THUNDERSTORMS WERE LOCATED ALONG A LINE
EXTENDING FROM NEAR MARQUETTE TO NEAR STRAWBERRY POINT...MOVING EAST
AT 45 MPH.

HAZARD...60 MPH WIND GUSTS. 

SOURCE...RADAR INDICATED. 

IMPACT...EXPECT DAMAGE TO ROOFS...SIDING...AND TREES. 

THESE SEVERE STORMS WILL BE NEAR...
  MCGREGOR AND MARQUETTE AROUND 705 PM CDT. 

OTHER LOCATIONS IMPACTED BY THESE SEVERE THUNDERSTORMS INCLUDE
LUANA... WADENA...ST. OLAF...GARBER AND OSTERDOCK.

PEOPLE ATTENDING THE CLAYTON COUNTY FAIR SHOULD SEEK SAFE SHELTER
IMMEDIATELY!

PRECAUTIONARY/PREPAREDNESS ACTIONS...

FOR YOUR PROTECTION MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR OF A
BUILDING.

INTENSE THUNDERSTORM LINES CAN PRODUCE BRIEF TORNADOES AND
WIDESPREAD SIGNIFICANT WIND DAMAGE. ALTHOUGH A TORNADO IS NOT
IMMEDIATELY LIKELY...IT IS BEST TO MOVE TO AN INTERIOR ROOM ON THE
LOWEST FLOOR OF A BUILDING. 

TORRENTIAL RAINFALL IS OCCURRING WITH THESE STORMS. DO NOT DRIVE
YOUR VEHICLE THROUGH FLOODED ROADWAYS.

&&

LAT...LON 4264 9189 4265 9189 4308 9160 4308 9118
      4291 9114 4290 9113 4264 9116
TIME...MOT...LOC 0001Z 275DEG 40KT 4304 9124 4264 9154 

HAIL...<.75IN
WIND...60MPH
 
$$

DAB

100 
WWUS53 KARX 050013
SVSARX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE LA CROSSE WI
713 PM CDT THU AUG 4 2016

IAC065-050021-
/O.CAN.KARX.SV.W.0069.000000T0000Z-160805T0030Z/
FAYETTE IA-
713 PM CDT THU AUG 4 2016

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN FAYETTE COUNTY IS
CANCELLED...

THE STORMS WHICH PROMPTED THE WARNING HAVE MOVED OUT OF THE WARNED
AREA. THEREFORE THE WARNING HAS BEEN CANCELLED.

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL MIDNIGHT CDT FOR
NORTHEASTERN IOWA...AND SOUTHWESTERN WISCONSIN.

LAT...LON 4267 9161 4308 9144 4308 9118 4291 9114
      4290 9113 4264 9116 4264 9160 4265 9161
TIME...MOT...LOC 0011Z 275DEG 40KT 4303 9110 4263 9139 

$$

IAC043-050030-
/O.CON.KARX.SV.W.0069.000000T0000Z-160805T0030Z/
CLAYTON IA-
713 PM CDT THU AUG 4 2016

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 730 PM CDT
FOR CLAYTON COUNTY...

AT 711 PM CDT...SEVERE THUNDERSTORMS WERE LOCATED ALONG A LINE
EXTENDING FROM NEAR PRAIRIE DU CHIEN TO EDGEWOOD...MOVING EAST AT 45
MPH.

HAZARD...60 MPH WIND GUSTS. 

SOURCE...RADAR INDICATED. A 44 MPH WIND GUST WAS MEASURED NEAR
         EDGEWOOD AT 705 PM. 

IMPACT...EXPECT DAMAGE TO ROOFS...SIDING...AND TREES. 

THESE SEVERE THUNDERSTORMS WILL REMAIN OVER MAINLY RURAL AREAS OF
CLAYTON COUNTY...INCLUDING THE FOLLOWING LOCATIONS: LUANA...ST.
OLAF... GARBER...OSTERDOCK AND CLAYTON.

PEOPLE ATTENDING THE CLAYTON COUNTY FAIR SHOULD SEEK SAFE SHELTER
IMMEDIATELY!

PRECAUTIONARY/PREPAREDNESS ACTIONS...

FOR YOUR PROTECTION MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR OF A
BUILDING.

INTENSE THUNDERSTORM LINES CAN PRODUCE BRIEF TORNADOES. ALTHOUGH A
TORNADO IS NOT IMMEDIATELY LIKELY...IT IS BEST TO MOVE TO AN
INTERIOR ROOM ON THE LOWEST FLOOR OF A BUILDING. 

&&

LAT...LON 4267 9161 4308 9144 4308 9118 4291 9114
      4290 9113 4264 9116 4264 9160 4265 9161
TIME...MOT...LOC 0011Z 275DEG 40KT 4303 9110 4263 9139 

HAIL...<.75IN
WIND...60MPH
 
$$

DAB

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 4, 4:18 PM CDT	Severe Thunderstorm Warning	ARX	Allamakee	42 min
Aug 4, 5:47 PM CDT	Special Weather Statement	ARX	Allamakee, Chickasaw, Clayton, Fayette, Winneshiek	118 min
Aug 4, 6:09 PM CDT	Severe Thunderstorm Warning	ARX	Allamakee, Winneshiek	66 min
Aug 4, 6:44 PM CDT	Special Weather Statement	ARX	Allamakee, Clayton	91 min

Nearby

Severe Thunderstorm Warnings in Iowa, 2016 Every severe thunderstorm warning 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.