| Photograph of Stoughton tornado (via NWS) | |
| Date of tornado outbreak: | August 18, 2005 |
| Duration1: | 8 hours, 40 minutes |
| Maximum rated tornado2: | F3 tornado |
| Tornadoes caused: | 23 confirmed |
| Damages: | $42.537 million |
| Fatalities: | 1 |
| Areas affected: | Wisconsin, Minnesota, Illinois |
|
1Time from first tornado to last tornado |
|
The August 2005 Wisconsin tornado outbreak was an outbreak of tornadoes that occurred primarily in southern Wisconsin on August 18, 2005. Another tornado touched down in Minnesota. A total of 27 tornadoes were confirmed that day in Wisconsin, the most tornadoes recorded in the state in a single day.[1] This broke the previous record of 24 tornadoes set on May 8, 1988. The system generating the Stoughton tornado was also accompanied by many reports of severe winds and hail throughout the region.
| Confirmed Total |
Confirmed F0 |
Confirmed F1 |
Confirmed F2 |
Confirmed F3 |
Confirmed F4 |
Confirmed F5 |
| 27 | 11 | 13 | 2 | 1 | 0 | 0 |
The same system continued on to spawn severe weather in Southern Ontario, Canada, the next day.
Contents |
| List of confirmed tornadoes - Thursday, August 18, 2005 | ||||||
|---|---|---|---|---|---|---|
|
|
|
|
|
|
|
|
| Minnesota | ||||||
| F0 | N of Dexter | Mower, MN | 1750 | 0.1 miles (0.2 km) | Damaged a single livestock barn and flattened part of a corn field. Caused $6,000 in damages. | |
| Wisconsin | ||||||
| F0 | W of Centerville | Trempealeau | 1918 | 0.1 miles (0.2 km) | Remained in a grove of trees and damaged them along its extremely short path. Caused $1,500 in damages. | |
| F1 | W of Esofea | Vernon | 2046 | 1.2 miles (1.9 km) | 1 Injury One mobile home was destroyed, injuring an occupant. A few outbuildings were destroyed as well. Several other buildings suffered varying degrees of damage, and many trees and power lines were snapped. Caused $150,000 in damages. | |
| F2 | W of Liberty | Vernon, Richland | 2105 | 20 miles (32.2 km) | 3 Injuries Considerable damage in the village of Viola, every building suffered at least minor damage. Heavy damage to most trees. Caused $3.569 million in damages. | |
| F1 | Muscoda area | Grant, Richland | 2140 | 4 miles (6.4 km) | One home, which was under construction, was completely destroyed. Damage was sustained to about 10 homes. Many trees and power lines were snapped. Path crossed the Wisconsin River as a waterspout. Caused $245,000 in damages. | |
| F1 | Necedah area | Monroe, Juneau | 2154 | 0 miles (0.0 km) | 3 homes suffered minor damage and a construction site was destroyed. Significant damage to many trees. | |
| F0 | E of Avoca | Iowa | 1737 | 0 miles (0.0 km) | No damage was reported from this brief tornado. | |
| F1 | NE of Clyde | Iowa, Sauk | 1737 | 0 miles (0.0 km) | ||
| F1 | Spring Green | Sauk | 1737 | 0 miles (0.0 km) | No real structural damage, however there were many fallen or uprooted trees. | |
| F1 | Springville | Adams | 1737 | 0 miles (0.0 km) | Several mobile homes were damaged. | |
| F2 | Bluffview area | Sauk, Columbia | 1737 | 0 miles (0.0 km) | Many trees down, several buildings damaged and some crops destroyed. | |
| F0 | W of Merrimac | Sauk | 1737 | 0 miles (0.0 km) | Spotted along the Wisconsin River. | |
| F1 | NE of Westfield | Marquette | 1737 | 0 miles (0.0 km) | Many trees down and damage to at least one home. | |
| F0 | NE of Lodi | Columbia | 1737 | 0 miles (0.0 km) | No damage reported from this brief tornado. | |
| F3 | Stoughton area | Dane, Jefferson | 1737 | 0 miles (0.0 km) | 1 death - see section on this tornado. | |
| F0 | Dane | Dane | 1737 | 0 miles (0.0 km) | ||
| F1 | S of Rockdale | Dane | 1737 | 0 miles (0.0 km) | ||
| F0 | W of Fort Atkinson | Jefferson | 1737 | 0 miles (0.0 km) | First tornado of same tornado family as Stoughton tornado. Combined damage was minor. | |
| F1 | W of Fort Atkinson | Jefferson | 1737 | 0 miles (0.0 km) | Second tornado of same tornado family as Stoughton tornado. | |
| F1 | SW of Fort Atkinson | Jefferson | 1737 | 0 miles (0.0 km) | Third tornado of same tornado family as Stoughton tornado. | |
| F1 | S of Fort Atkinson | Jefferson | 1737 | 0 miles (0.0 km) | Fourth tornado of same tornado family as Stoughton tornado. | |
| F1 | S of Fort Atkinson | Jefferson | 1737 | 0 miles (0.0 km) | Fifth tornado of same tornado family as Stoughton tornado. | |
| F0 | SE of Fort Atkinson | Jefferson | 1737 | 0 miles (0.0 km)) | Sixth and final tornado of same tornado family as Stoughton tornado. | |
By far the most significant tornado of the day developed at 6:15 p.m. 2.0 miles (3.2 km) north of Oregon near Fitchburg, or approximately 5 miles (8 km) south of Madison proper. This large, intense tornado would track for 20.0 (32.2 km) miles into Jefferson County from Dane County. The unusually long-lived tornado traveled mostly east-southeasterly until just east of Stoughton where it began moving almost due easterly.
It passed through rural subdivisions and farms north of Stoughton at around maximum intensity and width of one-half mile (0.8 km), destroying or very heavily damaging 89 houses, heavily damaging 67 houses, with lighter damage to 84 more. Damages from the tornado totaled to $36.89 million. One person was killed and 23 were injured, three seriously. Debris from the Stoughton area was found as far away as Waukesha and Milwaukee counties (two and three counties to the east). This tornado was rated a high-end F3 on the Fujita scale (an F4 rating was considered for it) with 205 mph winds, 1 mph away from the F4 threshold. Federal disaster assistance was requested but the Federal Emergency Management Agency (FEMA) denied a federal disaster area declaration.
Early estimates of the path length and width appeared to point to the tornado rating F5 in the estimates of some experts. Inspection of the damage and determination that the Jefferson County tornado was separate from the Stoughton tornado as well as downward adjustment of path width led to the F4 and later high end F3 ratings. If the tornado did indeed rate F5, it would have been one of a half-dozen or fewer to occur in Wisconsin during the last 120 years.
Initial reports of portions of the path of tornado expanding to over one and a half miles in diameter over farm and swamp land west of US Highway 51 and possibly a second time when the circulation of the tornado may have been partially over Lake Kegonsa making it difficult or impossible to measure the path width at this point. Also seen was a possible touchdown of a smaller, clockwise-rotating tornado on a shorter, parallel path about 5 km/~3 mi north in the town of Dunn initially visible as a funnel cloud from the south end of McFarland. Observers estimated the tornado on the ground to have been of F0 (40-74 mph) or F- (sub-39 mph) intensity, leading to minimal damage which was hard to distinguish from effects of straight-line winds therefore the tornado touchdown never confirmed officially.
The damage pattern in the built-up areas of the tornado path and effects on crops and other plants and soil strongly suggest the existence of several suction vortices within the main tornado funnel and/or evolution into a multi-vortex tornado and back before lifting off the ground.
The tornado frequently changed in size and form and eventually became somewhat rain-wrapped after being highly visible; and finally lifted 2.2 miles (3.5 km) north of Busseyville at 7:08 p.m. after traveling 20.0 miles (32.2 km) in an exceptional 53 minutes of continuous track. Numerous other tornadoes occurred during and after this tornado (seven as part of the tornado family associated with the Stoughton supercell, with the last tornado lifting at 7:53 p.m.. Ft. Atkinson was hit three times.
The parent thunderstorm dropped roof shingles and other objects from the Stoughton area on the NWS office in Sullivan, Wis. and parts of Waukesha and Milwaukee counties, 50 and more miles / 80 km away.
One death was attributed to this tornado. Loss of life was likely minimized due to the efforts of the NWS, local spotters, and Dane County emergency managers. Tornado warnings were put out well in advance of the developing tornado, and TVS (Tornadic Vortex Signatures which NWS WSR88D doppler radar detects) were seen in the Oregon area in advance of the tornado's approach. Spotters maneuvered to the area of the TVS, and once confirmed, sirens were sounded.
Some confusion was caused due to an F0 Tornado occurring in a similar time frame in Columbia County near Lodi, some mistakenly felt the danger had either passed, or was not threatening them.
The Stoughton tornado struck on the day after a devastating fire at one of the city's largest churches (cause unrelated to severe weather) and was the climax of a two-day spate of severe weather in Southern Wisconsin; the previous day several superbolts of lightning were reported as having done extensive damage at various sites in Madison and other Dane County communities including one incident in which a tree many feet in diameter literally exploded when hit by a bolt apparently from a storm 7–10 miles away and with the sun shining at the location at the time.
On the afternoon of August 19, 2005, the same low pressure system spawned tornadoes damaging homes in Southern Ontario, Canada. The storms morphed into heavy rain cells when reaching Toronto. The Insurance Bureau of Canada has estimated that insured losses where the highest in the province's history, exceeding $500 million canadian dollars, two and a half times Ontario's losses during 1998 ice storm and the second largest loss event in Canadian history.[1]