Alert archive / Minnesota / Severe Thunderstorm Warnings in 2012

Severe Thunderstorm Warning 69, NWS La Crosse, WI

July 18, 2012Fillmore County, Minnesota; Winneshiek County, Iowa

NWS La Crosse, WI issued this severe thunderstorm warning at Jul 18, 2012, 3:19 PM CDT for Fillmore County, Minnesota; Winneshiek County, Iowa. It was in force for 41 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: Jul 18, 2012, 3:19 PM CDT (20:19 UTC)
Expired: Jul 18, 2012, 4:00 PM CDT
In force: 41 min
Issued by: NWS La Crosse, WI
Area: Storm-based polygon
Hail: 1.5 in
Wind: 60.0 mph

Counties Winneshiek County, IA, Fillmore County, MN

The radar

The La Crosse radar (KARX), 67 km from the middle of the area, began a volume at 20:20 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 18, 3:27 PM CDT	TSTM WND GST 53	Harmony, MN
Jul 18, 3:28 PM CDT	HAIL 1.75	Ridgeway, IA
Jul 18, 3:40 PM CDT	TSTM WND DMG	Hesper, IA	TREES DOWN IN TOWN.
Jul 18, 3:45 PM CDT	TSTM WND DMG	2 S Highlandville, IA	CORN BENT OVER AND SEVERAL TREES UPROOTED.
Jul 18, 3:50 PM CDT	TSTM WND DMG	1 N Decorah, IA	LARGE TREE UPROOTED.
Jul 18, 4:00 PM CDT	TSTM WND GST 50	Decorah, IA
Jul 18, 4:01 PM CDT	TSTM WND GST 65	4 N Calmar, IA

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 18, 12:58 PM CDT	Severe Thunderstorm Watch	SPC	7 hr

The nearest sounding before it

Minneapolis, MN (KMPX), launched 12:00Z, 8.3 hours before the alert went out and 203 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: 2062 J/kg
Mixed-layer CIN: -144 J/kg
Mixed-layer LCL: 716 m above ground
0-6 km bulk shear: 23 kt
0-1 km storm-relative helicity: 174 m²/s²
0-3 km storm-relative helicity: 185 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 12.6

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

188 
WUUS53 KARX 182019
SVRARX
IAC191-MNC045-182100-
/O.NEW.KARX.SV.W.0069.120718T2019Z-120718T2100Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE LA CROSSE WI
319 PM CDT WED JUL 18 2012

THE NATIONAL WEATHER SERVICE IN LA CROSSE HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  NORTHERN WINNESHIEK COUNTY IN NORTHEAST IOWA...
  SOUTHEASTERN FILLMORE COUNTY IN SOUTHEAST MINNESOTA...

* UNTIL 400 PM CDT

* AT 315 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  SEVERE THUNDERSTORMS ROUGHLY ALONG A LINE EXTENDING FROM HARMONY TO
  RIDGEWAY TO DECORAH...MOVING NORTHEAST AT 15 MPH. THESE STORMS CAN
  PRODUCE PING PONG BALL SIZE HAIL AND DAMAGING WINDS IN EXCESS OF 60
  MPH.  

* THE SEVERE THUNDERSTORMS WILL BE NEAR...
  DECORAH AROUND 335 PM...
  HARMONY AROUND 340 PM...
  CANTON AROUND 345 PM...
  MABEL AROUND 400 PM...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

IF YOU ARE IN THE PATH OF THESE STORMS...PREPARE IMMEDIATELY FOR
LARGE HAIL AND DAMAGING WINDS. SEEK SHELTER NOW INSIDE A STURDY
STRUCTURE AND STAY AWAY FROM WINDOWS.

TORRENTIAL RAINFALL FROM THESE STORMS MAY ALSO CAUSE THE PONDING OF 
WATER ON ROADWAYS AND LOCALIZED FLOODING. MOVE OFF OF AREA RIVERS.

&&

LAT...LON 4373 9194 4375 9173 4350 9173 4350 9161
      4333 9160 4331 9161 4320 9189 4338 9209
      4350 9208 4350 9226 4353 9230
TIME...MOT...LOC 2019Z 232DEG 12KT 4353 9211 4342 9195
          4328 9186
WIND...HAIL 60MPH 1.50IN

$$

SHEA

2 follow-up statements

972 
WWUS53 KARX 182029
SVSARX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE LA CROSSE WI
329 PM CDT WED JUL 18 2012

IAC191-MNC045-182100-
/O.CON.KARX.SV.W.0069.000000T0000Z-120718T2100Z/
WINNESHIEK IA-FILLMORE MN-
329 PM CDT WED JUL 18 2012

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT FOR SOUTHEASTERN
FILLMORE AND NORTHERN WINNESHIEK COUNTIES UNTIL 400 PM CDT...

AT 324 PM CDT...DOPPLER RADAR INDICATED THUNDERSTORMS FROM HARMONY 
MINNESOTA TO JUST WEST OF DECORAH IOWA. LARGE HAIL IS LIKELY FALLING 
JUST WEST OF DECORAH.

RIDGEWAY IS LIKELY SEEING LARGE HAIL. IF YOU LIVE IN DECORAH OR JUST 
NORTH OF TOWN...INCLUDING LUTHER COLLEGE...PREPARE FOR LARGE HAIL. 
STAY AWAY FROM WINDOWS. PROTECT YOUR VEHICLES. MOVE INDOORS NOW!

* THE SEVERE THUNDERSTORMS WILL BE NEAR...
  DECORAH AROUND 335 PM...
  HARMONY AROUND 340 PM...
  CANTON AROUND 345 PM...
  MABEL AROUND 400 PM...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

THIS IS A DANGEROUS SITUATION. IF YOU ARE IN THE PATH OF THESE
STORMS...PREPARE IMMEDIATELY FOR DESTRUCTIVE HAIL...WHICH CAN
SIGNIFICANTLY DAMAGE ROOFS...WINDOWS...SIDING AND VEHICLES. DAMAGING
WINDS ARE ALSO EXPECTED...WHICH WILL UPROOT TREES AND DOWN POWER
LINES. SEEK SHELTER NOW INSIDE A STURDY STRUCTURE AND STAY AWAY FROM
WINDOWS.

TORRENTIAL RAINFALL FROM THESE STORMS MAY ALSO CAUSE MINOR FLOODING 
AND BRING AREA CREEKS AND STREAMS UP VERY QUICKLY.

&&

LAT...LON 4373 9194 4375 9173 4350 9173 4350 9161
      4333 9160 4331 9161 4320 9189 4338 9209
      4350 9208 4350 9226 4353 9230
TIME...MOT...LOC 2027Z 232DEG 12KT 4355 9208 4344 9192
          4330 9183
WIND...HAIL 60MPH 2.50IN

$$

SHEA

033 
WWUS53 KARX 182046
SVSARX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE LA CROSSE WI
346 PM CDT WED JUL 18 2012

IAC191-MNC045-182100-
/O.CON.KARX.SV.W.0069.000000T0000Z-120718T2100Z/
WINNESHIEK IA-FILLMORE MN-
346 PM CDT WED JUL 18 2012

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT FOR SOUTHEASTERN
FILLMORE AND NORTHERN WINNESHIEK COUNTIES UNTIL 400 PM CDT...

AT 343 PM...DOPPLER RADAR INDICATED THUNDERSTORMS FROM HARMONY 
MINNESOTA TO NEAR DECORAH IOWA MOVING SLOWLY NORTHEAST. LARGE HAIL 
HAS ALREADY BEEN REPORTED WEST OF DECORAH. AROUND DECORAH AND NORTH 
ON HIGHWAY 52 MAY EXPERIENCE TORRENTIAL RAINS IN ADDITION TO LARGE 
HAIL AND FREQUENT LIGHTNING. UP TO 2 INCHES OF RAIN MAY FALL BEFORE 
ENDING.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

IF YOU ARE IN THE PATH OF THESE STORMS...PREPARE IMMEDIATELY FOR
LARGE HAIL AND DAMAGING WINDS. SEEK SHELTER NOW INSIDE A STURDY
STRUCTURE AND STAY AWAY FROM WINDOWS.

TORRENTIAL RAINFALL FROM THESE STORMS WILL ALSO CAUSE MINOR 
FLOODING.

&&

LAT...LON 4373 9194 4375 9173 4350 9173 4350 9161
      4333 9160 4331 9161 4320 9189 4338 9209
      4350 9208 4350 9226 4353 9230
TIME...MOT...LOC 2044Z 232DEG 12KT 4357 9195 4346 9179
          4332 9170
WIND...HAIL 60MPH 1.50IN

$$

SHEA

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 18, 12:40 PM CDT	Severe Thunderstorm Warning	ARX	Dodge, Mower	50 min
Jul 18, 1:29 PM CDT	Severe Thunderstorm Warning	ARX	Mower	61 min
Jul 18, 2:24 PM CDT	Severe Thunderstorm Warning	ARX	Fillmore	51 min
Jul 18, 3:57 PM CDT	Severe Thunderstorm Warning	ARX	Houston	39 min
Jul 18, 3:22 PM CDT	Severe Thunderstorm Warning	ARX	Chickasaw	38 min

Nearby

Severe Thunderstorm Warnings in Minnesota, 2012 Severe Thunderstorm Warnings in Iowa, 2012 Every severe thunderstorm warning in 2012

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.