April 10th Tornado Outbreak Tied for Biggest Wisconsin April Outbreak Ever (updated Apr 12th, 8 am)

                       The potential for a tornado outbreak in the Wisconsin area for April 10th was advertised almost a week out.  Although the major metro areas like Madison, Milwaukee, and Chicago were spared, at least 10 tornadoes including a couple of strong tornadoes have already been documented in portions of mainly rural central and northern Wisconsin.  

...BIGGEST APRIL TORNADO OUTBREAK IN WISCONSIN HISTORY...

APRIL 10 2011 WILL GO DOWN AS ONE OF THE BIGGER TORNADO OUTBREAKS IN
WISCONSIN HISTORY.  IT IS TIED FOR THE BIGGEST TORNADO OUTBREAK IN
TERMS OF NUMBERS OF TORNADOES IN ONE DAY IN THE MONTH OF APRIL
(APRIL 27 1984-WALES F4 IN WAUKESHA COUNTY)

SO FAR...AT LEAST 10 TORNADOES HAVE BEEN CONFIRMED AS THREE NWS
OFFICES ARE COMPLETING STORM SURVEYS.

HERE ARE THE TORNADO TOTALS SO FAR:

NWS GREEN BAY AREA:    7*
NWS LA CROSSE AREA:    2
NWS TWIN CITIES AREA:  2

THE TOTAL SO FAR IS 10* TORNADOES.  ONE OF THE TORNADOES CROSSED
FROM ADAMS INTO WAUSHARA COUNTY...WHICH CROSSES FROM NWS LA CROSSE
COUNTY WARNING AREA TO THE GREEN BAY (THUS ONLY 10 TORNADOES...NOT
11 AS THE MATH ABOVE WOULD SUGGEST).

ACCORDING TO NWS GREEN BAY...THIS NUMBER OF 7 TIES FOR THE BIGGEST
TORNADO OUTBREAK EVER IN NORTHEAST AND CENTRAL WISCONSIN...THEIR
AREA OF WARNING RESPONSIBILITY. ADDITIONAL SURVEYS AND INVESTIGATION
COULD LEAD TO ADDITIONAL DOCUMENTED TORNADOES IN THE COMING DAYS.

HOW MANY TORNADOES HAS WISCONSIN HAD IN ONE DAY?

WISCONSIN NORMALLY DOESN/T HAVE MANY TORNADOES OCCURRING ON THE SAME
DAY...CONSIDERING IT AVERAGES ONLY 21 TORNADOES PER YEAR.  HOWEVER...
WHEN A TORNADIC WEATHER PATTERN DOES SET UP OVER WISCONSIN...THE
BADGER STATE CAN HAVE MANY TORNADOES OCCURRING ON THE SAME DAY.

THE TABLE BELOW LISTS THOSE DAYS IN WISCONSIN WITH THE LARGEST
NUMBER OF DOCUMENTED TORNADOES GOING BACK TO 1844. THE 10 TORNADOES
DOCUMENTED ON APRIL 10 2011 PLACES THAT DAY TIED FOR 9TH POSITION
IN THE TOP-10 RANKINGS.

     ...RANK...      ...DATE...      ...NUMBER OF EVENTS...

         01          AUGUST 18 2005            27

         02          MAY 08 1988               24

         03          JULY 03 1983              22

         04          JUNE 08 1993              18

         05          JUNE 23 2004              17

         06          JUNE 07 2008              13

         06          AUGUST 09 1979            13

         08          JULY 18 1996              12

         09          MAY 24 1989               10

         09          APRIL 27 1984             10

         09          JULY 15 1980              10

         09          JUNE 26 1969              10

         09          JULY 10 1966              10

         09          JUNE 04 2005              10

         09          JULY 22 2010              10

      ***09***       APRIL 10 2011             10

THE NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN FORECAST OFFICE
SERVICES 20 COUNTIES IN SOUTH-CENTRAL AND SOUTHEAST WISCONSIN. THIS
COUNTY WARNING AREA /CWA/ CONSISTS OF THE FOLLOWING COUNTIES...

COLUMBIA...DANE...DODGE...FOND DU LAC...GREEN...GREEN LAKE...
IOWA...JEFFERSON...KENOSHA...LAFAYETTE...MARQUETTE...MILWAUKEE...
OZAUKEE...RACINE...ROCK...SAUK...SHEBOYGAN...WALWORTH...
WASHINGTON...AND WAUKESHA...

NO TORNADOES WERE DOCUMENTED IN THIS AREA. THE WORST STORMS MISSED
OUR AREA BY ONE COUNTY TO THE NORTH.

BELOW IS THE TOP-10 RANKING FOR THOSE DAYS WITH THE LARGEST NUMBER
OF DOCUMENTED TORNADOES ON A GIVEN DAY IN THE MILWAUKEE/SULLIVAN CWA.

     ...RANK...      ...DATE...      ...NUMBER OF EVENTS...

         01          AUGUST 18 2005            16

         02          MAY 08 1988               10

         02          AUGUST 09 1979            10

         02          JULY 18 1996              10

         02          JUNE 07 2008              10

         02          JULY 22 2010              10

         07          JUNE 08 1993              08

         07          JUNE 23 2004              08

         09          JUNE 08 1984              07

         09          JUNE 12 2008              07

 

April 10 2011 will go down at least tied for the biggest one-day Tornado Outbreak in Wisconsin History during the month of April.  The other big April tornado outbreak was on April 27 1984, when 10 tornadoes occurred.  This included the violent Wales Tornado in Waukesha County, rated an F4.

So far, two strong tornadoes have been surveyed.  An EF2 in Adams County, and at least an EF2 in Marathon County near Merrill WI.  For the month of April in Wisconsin, these are the first strong tornadoes in 17 years (April 26 1994 in NW Wisconsin).  They are the first strong tornadoes in 27 years in the month of April for central or southern WI (April 27 1984). 

Since damage assessments continue, more tornadoes may be found and recorded in the next few days.



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