[1] Severe weather had raked parts of the U.S. Midwest the day before, where seventeen F2 or greater tornadoes touched down (ten in Illinois alone).

A cold front was being dragged eastward into unusually warm and unstable air associated with a strong storm system moving through the northern tier of the U.S. Out of the two significant tornadoes that day, both rated F3, it was remarkable that there were no deaths.

[2] Ahead of the main cold front, a separate storm formed into a supercell southwest of Williamsford in Grey County, likely triggered by the aging squall line further west.

The collective width of the damage path was about 400 metres (440 yards) wide and extensive debris filled the air.

The tornado continued to move northeast and, as it neared Holland Centre, the winds hurled a 10,000-litre (2,600-US-gallon) gasoline tank (weighing approximately two tonnes) for more than 1.6 kilometres (1,700 yards).

The storm in Wellington County initially formed northwest of London around 5:00pm and slowly moved northeast where it began to produce funnel clouds.

The tornado had a separate companion for a brief time, a thin black appendage that swept around the front of the main circulation.

As the storm moved farther to the northeast, it nearly destroyed several farms before it plowed into the Luther Marsh, north of Grand Valley.

The tornado damaged more homes and then crossed Highway 25, taking down several hydro transformers in one very bright power flash.

Pieces of sheet metal and wood fell from the sky and littered the southern end of town after they were thrown out of the tornado.

In fact, the Grey County tornado lifted a thick sheet of ice off of a pond before depositing it nearby.

Light snows also fell after the event in the areas hardest hit by the tornadoes, which hampered the clean-up efforts.