EF1 tornado in Green County, Wisconsin

This weak tornado spun up in the rural area roughly mid-way between New Glarus and Postville, just northeast of Zentner Road about 0.8 miles north-northwest of the intersection of CTH H and Zentner Road. It moved northeast, clipping the northwest part of the city of New Glarus, and exited Green County going through the western edge of the city of Belleville. Luckily only uprooted trees or snapped-off tree damage was noted. This tornado finally dissipated about 2 miles south-southeast of the village of Paoli in south-central Dane County near CTH A. The path length was about 7.84 miles in Green County and 4.41 miles in Dane County, for a total path length of about 12.25 miles. The starting and ending locations in Green County, with respect to lat/long pairs of numbers, were 42.80215/-89.69455 and 42.85690/-89.55898. DI#27 (TH), DOD3. Wind speeds estimated at 83-87 knots (95-100 mph). Average path width in Green County was about 75 yards.

A series of clusters of strong to severe storms ahead of a cold front moved east/northeast across south-central and sourtheast Wisconsin. Copious amounts of moisture were available that allowed repeated heavy rains. Additionally, there was sufficient vertical wind shear to allow for the generation of supercell thunderstorms with rotating updrafts that led to seven tornadoes in this part of the state of Wisconsin. The flooding rains constituted the 2nd round/punch of heavy rains that led to more widespread and severe flash flooding and record-setting river flooding (1st punch was Jun 7-9, 2008).

The axis of heavy rains on June 12th extended from Lafayette County northeast through Dane County to eastern Green Lake County and western Fond du Lac County. Generally 4 to 6 inches fell in this area, with 1 to 4 inches elsewhere. The generous rains in June at Milwuakee led to a montly total of 12.27 inches. This easily broke the record for highest June rainfall total. The previous record was 10.13 inches, set in 1917, and also makes June, 2008, the wettest month ever at Milwaukee.

The Rock River crested at all-time record high levels at the following gauage sites: Waupun (10.07' on 6/13), Horicon (10.29' on 6/17), Watertown (7.81' on 6/13), Jefferson (15.64' on 6/18), Ft. Atkinson (10.85' on 6/21), Newville (15.12' on 6/21), Indianford (18.33' on 6/21), and Afton (13.51' on 6/21). Likewise, the Crawfish River set a new all-time high crest of 13.59' on 6/16 at Milford, and Beaver Dam Creek set a new record of 843.53' on 6/16 at Beaver Dam. Other, new, all-time record high crests include 4.47' on 6/9 on the Bark River at Rome, 4.95' on 6/13 on the Mukwonago River at Mukwonago, 11.41' on 6/8 on Oak Creek in South Milwaukee, 13.93' on 6/13 on the Milwaukee River near Cedarburg, 13.54' on 6/15 on the Fox River at Burlington, and 15.18' on 6/15 on the Fox River at New Munster.

High water levels generaged major road blocks, for various periods, on Interstate 94 in Jefferson and Waukesha Counties, on Interstate 894 in Milwaukee, and on Interstate 39/90/94 in Columbia County near Portage. Most inland lakes rose to high levels that resulted in minor shoreline damage to piers, etc.