EF2 Tornado — Waukesha, Wisconsin

2010-06-21 · near Eagle, Waukesha, Wisconsin

Event narrative

An EF2 tornado developed about 1.9 miles west-southwest of the Village of Eagle, roughly 1/2 mile south-southeast of the intersection of STH 59 and CTH S, just west of CTH S and west of a horse-riding ranch, and moved east-northeast through the Eagle and then moved due east and then east-southeast before dissipating about 1.94 miles southeast of Jericho, just within Mukwonago County Park, 1000 feet east of Genevieve Drive. Fifteen people sustained minor injuries. One hundred thirty-four homes received minor damage, 67 homes had major damage, and 8 homes were destroyed, mainly in the southern part of the village. Another 75 homes were minimally affected. One business received major damage, while 18 businesses had minor damage. The business that received major damage was a commercial horse-riding ranch/western town at the beginning of the tornado path. Damage was inflicted upon all of the fencing, two trolleys, and 18 tables. One of the biggest buildings on the site was twisted and turned. A donkey was killed, four hayride wagons were lost, and 25 acres of trees were damaged. The owner of the riding ranch saw the tornado and said it looked like the Fourth of July fireworks finale - there were thousands of lightning streaks in the cone. All together, this tornado uprooted or damaged thousands of trees, and at least three dozen vehicles were damaged or totaled. At Old World Wisconsin, an outdoor museum operated by the Wisconsin Historical Society near Eagle, about 2500 tress were damaged at this site alone, and a few buildings sustained minor damage. Overall, Emergency Management officials estimated that residential damage reached $20,577,500, with business damage around $311,500, bringing total private sector damage to about $20,889,000. A few agricultural buildings were damaged, but loss estimates were not available. Public sector structural damage totaled only about $600, while public sector service costs (non-damage) such as debris clean-up, security and public protection, road protective measures, and other miscellaneous expenses were estimated at $101,965. The starting point location was Lat. 42.86785 Lon.-88.50307. The end point location was Lat.42.87100 Lon. -88.40003. The EF-rating was based on DI 2 (FR12) DOD 6 which suggests wind speeds between 125 to 130 mph. On the WSR-88D Doppler radar at the nearby WFO Milwaukee (MKX), a debris-ball appeared near Eagle within a classic hook echo as the parent thunderstorm moved east.

Wider weather episode

Strong to severe thunderstorms developed across much of south central and southeast Wisconsin during the evening of June 21, 2010. A vigorous upper level disturbance helped to support deep vertical motions in the atmosphere, along with strong deep layer wind shear. This lift acted on a warm and very moist atmosphere, carried into the region on a 40 to 50 knot low-level jet. The result was powerful rotating thunderstorms, with damaging straight line winds, large hail, and in this case, 5 tornadoes. At one point during the height of the event, around 48,000 customers in southeast Wisconsin were without electric power due to downed power lines. However, power-line and power-pole loss estimates were not available and do not show up as damage amounts in any individual event within this severe weather episode.

View location on OpenStreetMap → (42.8683, -88.5041)

Source: NOAA Storm Events Database, event_id 245455. Narrative written by the NWS forecast office that issued the report.