Canadian historic event
Edmonton tornado July 31, 1987
On the Friday before a long weekend, an F4 tornado carved a 40-kilometre path through eastern Edmonton, killing 27. Canadians call it Black Friday — and it transformed how Canada warns for severe weather.
The overview
- Date: July 31, 1987, roughly 3:00-4:00 PM.
- Location: eastern Edmonton, Alberta.
- Rating: F4 — winds estimated over 400 km/h in the worst swaths.
- Deaths: 27 (15 at the Evergreen Mobile Home Park alone).
- Injuries: 300+.
- Path: about 40 km, on the ground for roughly an hour.
- Damage: over $330 million (1987 CAD) — Canada's costliest tornado at the time.
The path of destruction
- The tornado tracked north along Edmonton's eastern edge.
- Industrial areas in Strathcona County were shredded — workers died in collapsed buildings.
- The Evergreen Mobile Home Park took a direct hit: 15 dead, hundreds of homes destroyed.
- Hail up to softball size accompanied the storm.
- The tornado was rain-wrapped for portions of its life — many victims never saw it.
The aftermath
- Environment Canada overhauled its severe weather warning system.
- Emergency Public Warning System (later Alberta Emergency Alert) was created as a direct result.
- Edmonton adopted the slogan "City of Champions" partly in reference to the community response.
- Mobile home safety became a national conversation in Canada.
- Annual remembrance continues in Edmonton.
The meteorology
- An intense supercell developed in an unusually volatile air mass for central Alberta.
- Very high CAPE and strong shear — a Plains-style setup rare at that latitude.
- The storm also produced record hail and flash flooding.
- Modern reanalysis suggests winds near the top of the F4 range.
- It remains one of only a few F4s ever recorded in Canada.
Lessons that still apply
- Mobile home parks need dedicated community shelters — the Evergreen tragedy is Canada's defining example.
- Warning systems must reach people outdoors, at work, and on holiday weekends.
- Rain-wrapped tornadoes demand radar-based warnings, not visual confirmation.
- Alberta's modern emergency alert system exists because of this storm.