Storm Damage Survey - 5 May 2000

Overview

On 5 May 2000, a thunderstorm developed near Bancroft near 1915 UTC and moved toward the southeast. At 2040 UTC, a report of a tornado was received via the Madoc OPP by RCTO (see Appendix A). Only minor damage was reported.

A damage survey was conducted the following day, 6 May 2000. There was minor damage to a house and numerous trees felled from various directions. It was concluded from the damage that an F0 tornado travelled from roughly N to S over a distance of approximately 10 km. Additional and subsequent information from witnesses supported this conclusion. The author estimates the damage to be on the order of $20 000.
 

Investigation

The Madoc OPP related the location of damage and kindly provided detailed maps of the area. The first location visited was the home of Dean and Hilda Wehring at 123 Hass Road, roughly 5 km south of Cooper (a detailed map is provided near the end of the document). They had reported that their chimney was knocked off and that is shown in the picture below.

Roughly 20m to the west of the house, several large trees were blown down from the south, as shown in the picture below.

A bit farther down the road to the west, there was tree damage due to winds from the north, as shown by the photo below.

Hilda Wehring said the storm came up at about 4:15 pm. At first it was windy with a lot of hail. Her husband opened the front door and encountered a whirlwind in the road. The screen door and a window were sucked from the house by the vortex. She related that roughly 100 trees, many large, were downed from various directions on their property approximately 1 km to the south of the house. She also said that the hail was about the size of a quarter and covered the ground.

Several other small pockets of felled trees were found on roads to the south of Hass Rd. Again, trees were down in various directions. On Queensborough Rd., which runs roughly east-west, there were numerous trees down from the north over a distance of roughly 1 km (see photo below). There was a hydro pole down about 1 km farther to the east.

There were also some metal siding panels found against a fence that appeared to be blown from the east or northeast. These are shown below.

Peter Henderson observed a tornado at around 4 pm from the corner of Cooper and Queensborough Roads, appropriately known as Hazzards Corners. He described a dark, wedge-shaped cloud hanging from the thunderstorm with 5 or 6 vortices below sucking up dirt and debris. Looking north, he watched the tornado move to the east then curve south. He said that it then seemed to encounter winds from the south and began to move from the east more toward his location. He said he observed the tornado over a 10-15 minute period. At his location, there were light showers and frequent lightning. To his east, he said he saw a wall of white that he thought was hail.

There were also other reports in the media of sightings of two funnel clouds. Mr. Henderson said he saw only one.

Conclusions

After analyzing the damage and witness accounts, it was concluded that a tornado occurred causing damage consistent with F0 intensity on the Fujita scale (Fujita, 1981). There were several areas where trees were found downed in various directions along a narrow damage path. The trees' orientations appeared to be consistent with a cyclonically rotating vortex. The damage track appeared to begin near 123 Hass Rd. and ended approximately 10 km to the south just north of Highway 7 (see map below). According to a witness, the tornado motion was initially to the east, then to the south, then finally back toward the west possibly displaced by thunderstorm outflow. The maximum damage path width appeared to be roughly 200 m. The time of the event was approximately 1615 EDT with a duration of 10-15 minutes. There were no reports of injuries or deaths. Damage was estimated by the author to be on the order of $20 000.

Post Script

The author was fortunate enough to drive through this same thunderstorm on Highway 401, sometime after the tornado had occurred. The rain grew increasingly heavy moving toward the west and slushy hail was briefly encountered. There appeared to be a lowering on the NW side of the storm and possibly a 'beaver tail' cloud formation off to the north, indicating that the inflow region may have been from the north side of the storm.
 

Reference

Fujita, T.T. 1981. Tornadoes and Downbursts in the Context of Generalized
    Planetary Scales. J. Atmos. Sci.38: 1511-1534.
 

Appendix A

SOURCE/WATCHER ID: OPP
EVENT TIME (UTC): 20-40
EVENT DAY: 5.0
MONTH: 5.0
YEAR: 2000.0
EVENT LOCALE: N OF MADOC
ASOCTD PUBLIC RGN: Peterborough and the Kawarthas
DETAILED DESCRIPTION: TORNADO REPORTED TO OPP N OF MADOC MOVING TOWARD TWEED.
TORNADO: POSSIBLE