1953 Sarnia tornado outbreak
The 1953 Sarnia tornado outbreak was a localized but devastating series of severe thunderstorms that affected the Great Lakes region during May 20-21, 1953. The strongest of these storms produced three intense, long-tracked tornadoes in Iowa, Michigan, and Ontario. The worst tornado event was a violent F4 tornado that tore through the cities of Port Huron, Michigan, and Sarnia, Ontario, on May 21, damaging or destroying hundreds of structures and causing dozens of casualties. Overall, the tornadoes killed eight people, injured 123 others, and caused at least $17.6 million in damage. Thunderstorm winds also caused an additional fatality when a tree fell on a house in Waterloo, Iowa.
Meteorological synopsis
A low pressure system formed over south central Montana early on May 20, 1953. This low moved eastward into South Dakota as favorable conditions to its east generated scattered severe thunderstorms across the Upper Midwest thanks in part to another low that was moving northeastward through Ontario. Continuing eastward, the original low moved into Minnesota by May 21 as it made a gradual northeastward turn, producing more severe weather across Ohio and Michigan until a high-pressure system pushed out of the area.Confirmed tornadoes
- According to Thomas P. Grazulis, an F2 tornado destroyed or damaged a motel and several barns as it affected six farms near Chelsea and Blairstown, Iowa before causing severe damage in Fairfax, on May 20. The tornado reportedly struck Tama and Benton counties in Iowa. However, it is not officially listed. It is also possible that this was actually the beginning stage of second Iowa F3 tornado listed below.
May 20 event
May 21 event
Port Huron, Michigan–Sarnia, Ontario
This large, violent tornado touched down at 4:21 p.m. CST near Smiths Creek, Michigan, southwest of Port Huron. It moved northeast and quickly strengthened before hitting Port Huron, resulting in widespread F3 and F4 damage. Two people were killed in Port Huron and 68 more were injured. Close to 400 homes were damaged or destroyed in the United States with monetary losses totaling $2.6 million. Crossing the St. Clair River, the tornado moved into Canada just south of Sarnia Harbour. Moving to the northeast, the tornado moved directly through Sarnia, Ontario, where almost 100 commercial buildings sustained damage. At least 150 homes on the more suburban outskirts of the city were damaged and in some instances reduced to rubble. Five people were killed in Sarnia. Before exiting Sarnia, the tornado curved even further to the northeast and began to weaken, as its path narrowed to approximately across. The tornado then restrengthened as it moved into rural Lambton and Middlesex Counties, where more F4 damage was inflicted upon farmsteads and homes near Nairn, before it dissipated south of Stratford. This suggested a total path length exceeding, though it is highly probable that this damage path was made up of more than one tornado, possibly as many as four.Overall, the tornado was on the ground for 2 hours and 39 minutes, tracked, and was wide at its peak. Seven people were killed, 117 others were injured, and damages were estimated $17.6 million.