Tornadoes and Flash Flooding in Wisconsin, June 1, 2000

One would be hard pressed to find another day like June 1, 2000 in terms of depth and range of severe, convective weather events across south-central and southeast Wisconsin. Tornadoes, widespread and localized flash flooding, funnel clouds, damaging hurricane-force, straight-line winds associated with a wicked squall-line, large hail stones, urban/small flooding, lightning strikes, and significant mainstem river flooding were reported. As in the preceding weeks, a quasi-stationary front over northern Illinois served as a boundary for warm, moist, unstable air to be pulled north over the cooler air over Wisconsin. Leftover flooding (from the evening of May 31, 2000) and isolated severe thunderstorms were noted during the pre-dawn to mid morning hours. However a powerful squall-line formed along the Mississippi River in the La Crosse area by mid-afternoon, and pushed into south-central Wisconsin by late afternoon with "all hell breaking loose." After the squall line moved into the southeast part of the state, it was followed by widespread showers and thunderstorms that triggered additional flooding problems. The east/southeast moving storms would not end until around 2300CST. As a result of the wild weather events, a State of Emergency was declared in Columbia, Dane, Dodge, Green, Iowa, Lafayette, Rock, and Sauk counties. Numerous power lines were knocked down by felled trees or wind gusts outright, resulting in the lose of power to 20,000 customers. Significant storm and flooding events will be summarized below county by county.Marquette Co: 6 homes were damaged and trees uprooted by powerful winds estimated at 70 knots (80 mph) in Briggsville. Urban flooding in Briggsville was also noted with water 6 inches deep.Green Lake Co: powerful winds knocked down trees in both Kingston and Markesan, and large hail was noted.Fond du Lac Co: a brief, F0 tornado spun up in the rural area southeast of Oak Center. Only some hay crop was damaged. Elsewhere, urban flooding and large hail was noted. Between 1700 and 1900CST, 1.71 inches of rain fell in the city of Fond du Lac.Sheboygan Co: powerful thunderstorm winds pushed over trees in the southern portions. Sauk Co: powerful winds blew over large trees in the Reedsburg to Baraboo area as well as around Prairie du Sac. Then the heavens oped up as 3.75 inches of rain fell between 1600 and 1645CST in North Freedom. There were other reports of up to 6 inches of rain falling in 2 hours. Flash flooding developed along Narrows Creek which left mud marks 8 feet high on some buildings. So much water came down Narrows Creek that it temporarily backed up the water of the Baraboo River! The Baraboo River flooded homes, and other creeks tore pieces of Highways 12 and 113 away. Road beds and parking lots were ripped away on the south side of Baraboo. Some railroad beds and many drainage culverts across the county were washed away. Severe erosion was noted on the cliffs overlooking the north shore of Devils Lake, whose water level rose about 3 feet due to runoff. All together, 153 residential homes were damaged, 17 businesses reported water damage, and 220,000 acres of farm land sustained water or erosion damage. The flooding was more widespread and worse than the 1993 flood, based on newspaper accounts. The Baraboo River near Baraboo crested at 22.04 feet on June 2nd, or 6.04 feet above flood stage (moderate flooding), after rising above flood stage at 0400CST on the 1st. Upriver at Rock Springs, the flood stage of 18.5 feet was exceeded at 1630CST on the 1st, and the crest was 21.71 feet at 0750CST on the 2nd (major flooding). Columbia Co: powerful winds uprooted large trees in and around Portage. In addition, a garage was damaged, several vehicles were blown into roadside ditches quickly reached a depth of 1 to 3 feet over portions of Highway 12 around Portage, and on Highway 73 in the southeast corner where residents were evacuated. Gravel road shoulder and culvert washouts were reported on some roads. Agricultural crop damage and soil erosion were also noted.Dodge Co: the main event was a long-lived tornado that spun up just south of Highway S about 4 miles south of Horicon, just southwest of the intersection of Highways S and E. Eyewitness accounts suggested that this tornado was a rain-wrapped and multi-vortex as it hopped-skipped east/southeast through the heart of the village of Iron Ridge (F2 at this time, 140-50 mph wind), before exiting the county on Highway S. All together, this F2 tornado destroyed 6 homes, and damaged 26 other homes, 6 businesses, 2 barns, 1 silo, semi-tractor trailer, a green house, and many cars. It destroyed 5 agricultural buildings. No one was injured or killed by this early-warned tornado. Five other barns were damaged in the county by the powerful straight-line winds associated with the squall-line. In addition, large hail up to walnut size was noted. Flash flooding was reported in the southeast part of the county when 1.5 inches of rain fell in a short period of time. Soil erosion and shoulder washouts were reported near the intersection of Highways 60 and P, south of Rubicon.Washington Co: the Dodge County tornado continued into Washington County for about 1.5 miles near and along Highway S. It damaged a barn and silo and uprooted more trees before dissipating. The tornado in this county had winds estimated at 80 mph, or F1 strength. No one was injured or killed. Flash flooding was reported south of Hartford where soil erosion and gravel shoulder washouts occurred due to swirling flood waters. Otherwise, large hail and tree-uprooting winds were noted in Germantown.Iowa Co: Pre-dawn flash flooding occurred across the northern portion of Iowa County due to leftover thunderstorms that hit the county on May 31st. Morrey Creek overflowed it banks in the village of Avoca, damaging 35 homes and eroding surrounding landscaping. In Dodge State Park near Dodgeville, 50 miles of trails were closed after several bridges were washed out by flooding waters. In addition, gravel road shoulder and culvert washouts were noted on several roads. Another round of flash flooding occurred across the northern portion of the county thanks to torrential rains of 2 to 4 inches in 1 to 2 hours in the late afternoon and early evening hours. An estimated 10,250 acres sustained major soil erosion and many roads had water depths of 1 to 3 feet as water currents washed away gravel shoulders. Crop damage was extensive. Dane Co: pre-dawn severe storms dumped large hail and knocked down many tree limbs in the Madison area. During the same storm, lightning struck a west-side Madison hotel, resulting in damage to its electrical system. Urban/small stream flooding was noted in the pre-dawn hours across the northern part of the county with water covering low spots on Highways 12, 73, and 113. A couple streets were flooded and closed in the village of Mazomanie due to high water levels on the Black Earth Creek. Sandbagging was needed to protect about a dozen homes in Mazomanie. Powerful thunderstorm winds uprooted trees which then damaged many vehicles in the Madison to Cottage Grove area during the evening. At least 60 trees blocked various roads in the Madison area, and 18 power lines were reported down. Roof tiles were also removed from some homes as the winds gusted to an estimated 70 knots (80 mph). An expensive gazebo was destroyed by uprooted trees in the city of Monona. Shortly thereafter, flash-flood producing rains hit much of the county. Madison streets were rivers as 27 cars were stranded or pushed around. It was the worst flooding the city during the past 15 years. Sandbagging commenced in Monona to protect homes. Many roads across the county were damaged by flood waters, with most damage in the northwest part of the county. In the village of Oregon, 1.90 inches of rain was measured in just 45 minutes ending at 1830CST. Additional soil erosion and ponding of water resulted in extensive, severe crop damage across the county. Collectively, wind and/or flood damage occurred to at least 646 residential homes in the county, and to 3 businesses. Probably 30,000 acres of farm land had significant crop damage. A new daily rainfall record of 3.46 inches was set at Madison's Traux Field, breaking the old record of 1.33 inches set back in 1892. Runoff from this rainfall eventually pushed Lake Mendota to 31.5 inches above its normal summer level on June 5th, which was the highest reading since the beginning of records in 1916. In response to the high lake levels in Dane county, many nearby homes were sandbagged, and public beach and boat docks were closed.Jefferson Co: an early morning, severe thunderstorm dumped large hail on Lake Mills. Another storm's lightning struck a Ft. Atkinson church steeple, resulting in structural and water damage. The evening storms generated damaging winds that uprooted large trees. Lightning started a minor fire on a Lake Mills home's roof. Heavy rains of 2 to 3 inches during the evening generated scattered flash flooding across the county, mostly in the form of gravel shoulder washouts of several roads. Roads near the Rock River in Ft. Atkinson were closed due to the swirling waters. Soil erosion and crop washouts were noted across the county. Rainfall totals of 2.39 inches and 2.72 inches were noted in Ft. Atkinson and Jefferson, respectively. The heavy rains forced the Crawfish River at Milford to exceed the flood stage of 7 feet on June 2nd , and crest at 8.38 feet on June 7th (moderate flooding). Waukesha Co: powerful thunderstorm winds uprooted trees in the Genesee area.Milwaukee Co: large hail was reported in the city of Milwaukee. Torrential rains of around 2 inches in 1 to 2 hours in the city of Fox Point resulted in flash flooding in that city. Landscaping damage and some road damage was noted due to swift water currents.Lafayette Co: a brief tornado occurred north of Calamine. It damaged 2 large pole sheds and uprooted many trees along its short path. Several calves were injured as they were pushed across the road. Eyewitness accounts suggest this F1 tornado (winds about 100 mph) was rain-wrapped. Otherwise, the squall line's powerful winds uprooted trees and over-turned a car-trailer combo east of Belmont. Similar to other counties, flash-flood producing rains followed the winds. Across the county, all mainstem river, stream, creeks, and other low spots experienced flash flooding. Bridge under-cutting was noted on Highway K outside of Gratiot, on Highway H in Jenkynsville, and Highway G in the northwest corner. Moderate to severe damage to road shoulders and washed out driveways was noted countywide. Twenty-one roads were closed at one time or another. At least 75 residential homes and 5 businesses reported flood damage, while 2 private utility buildings suffered damage. Two farm buildings were destroyed by the flood waters, and 15 others damaged. About 7000 acres of farm land were severely damaged. The Pecatonica River in Darlington closed down Highway 23 from the south. The river at this location exceeded the flood stage of 11 feet late on May 31st, and crested at 15.77 feet at 0730CST on June 1st (moderate flooding). Near South Wayne, lightning started a minor house fire.Green Co: pre-dawn and morning urban/small stream flooding occurred countywide due to rainfall that started on May 31st. The rains ended by sunrise. Up to 5 inches of rain fell overnight in the southwest part of the county. Many streams were 5 to 10 feet wide, resulting in water covering low-lying roads to a depth of 1 foot. Several cars were swept into roadside ditches. Urban basements had minor flood damage. Additional heavy rains followed the evening squall line which resulted in a new round of flash flooding across much of the county. Eight miles of the 24 mile long Sugar River State Trail were closed from near Monticello to near Albany due to washed out bridges and undercut paths. Five homes sustained significant damage. Numerous roads were closed due to high water levels and dozens of vehicles were stranded or pushed into roadside ditches. Gravel road shoulder and culvert washouts were noted countywide. Water levels in the city of Brodhead were the highest in many years. Legion Park in Albany was closed after the adjacent Sugar River exceeded flood stage. Moderate to severe soil erosion was noted to 5000 acres of farm fields. The Pecatonica River at Martintown exceeded the flood stage of 13.5 feet at 0000CST on June 1st, and crested at 18.51 feet on June 4th (moderate flooding).Rock Co: powerful thunderstorm winds downed large trees in scattered parts of the county. However, flash-flood producing rains hit during the evening hours. Most mainstem and nearly all streams and creeks jumped their banks. Nine roads along Lake Koshkonong sustained washout damage due to swift water currents. At least 100 homes outside of the major cities sustained damage. Many Beloit and Janesville homes in low spots reported landscape flood damage as well as basement flooding. Flash flood waters also tore through farm fields, leaving moderate to severe soil erosion and crop damage to at least 20,000 acres. Flood waters from the Sugar River in the southwest corner of the county closed roads west of the village of Avon.Walworth Co: no damage reports.Kenosha Co: several rounds of heavy rains during the evening on top of previously saturated soils and high river levels resulted in flash flooding scattered across the county. Several roads had fast-flowing waters 1 to 3 feet deep which resulted in shoulder washouts and cars being swept into roadside ditches. At least 75 homes sustained significant flood damage in the Wheatland, Salem, and Silver Lake areas. About 47,000 acres of farm land had serious soil erosion, and washed or flooded crops. Due to rainfall totals during the evening of 2 to 3 inches, the Fox River at New Munster continued to rise and would eventually crest at 12.76 feet early on June 3rd, or 2.76 feet above flood stage. Three homes Silver Lake homes were evacuated.