In the week preceding July 31, a low pressure system sitting over southwestern
British Columbia fed warm, humid air into central Alberta. Daytime heating along with near-record
dewpoints over Alberta triggered a series of strong thunderstorms that persisted throughout the week. On July 31, a cold front developed over western Alberta, colliding with the warm moist air that persisted over the region. Forecasters recognized the elevated risk for severe weather early in the day.
Weatheradio broadcasts and interviews with the media stressed "vicious thunderstorms" and "extremely strong and violent thunderstorms". At 3:04 pm, a tornado warning was issued for the city. The tornado moved into the southeast portion of the city as a
multiple-vortex tornado, and tracked north along the eastern portions of
Mill Woods, causing F2 to F3 damage. The tornado continued northward crossing the
Sherwood Park Freeway and eventually hitting the
Refinery Row area at F4 intensity. The tornado tossed several large oil tanks, levelled several industrial buildings, and several trailers were picked up and scattered at
Laidlaw and Byers Transport. Grass scouring and windrowing of debris occurred, and damage in that area may have been borderline F5, but was never officially ranked as such. The tornado weakened slightly as it passed over an open area between Baseline Road and the North Saskatchewan River. Still, it maintained F2 to F3 intensity as it tore through eastern parts of
Clareview toward 4:00 pm, causing heavy damage to several homes in
Kernohan,
Bannerman and
Fraser neighbourhoods before dissipating. Farther from the Edmonton area, an F2 tornado touched down in farmland between
Millet and
Vegreville and remained on the ground for , causing $40,000 in damages. == Post-disaster response ==