Updated: Oct 26, 2020
A Colorado Low brought an unusually warm and unstable airmass to Southern Ontario on Friday. Highs in the warm sector broke records in many places from London to Hamilton to Ottawa where some locations reached the mid 20s.
The same airmass also brought severe weather to a large swath of Ontario. Ahead of the cold front, a lake breeze boundary fired off severe thunderstorms in Simcoe County, which were met with an environment that was highly sheared and ripe for storms to become severe.
The environment itself consisted of modest instability, but strong wind shear which allowed for storms to rotate and create large hail and even triggered tornado warnings for the region. 3 separate supercells traversed the region after 3pm, with the first forming just west of Collingwood.
The first storm tracked over southern Georgian Bay and emerged near Balm Beach, and moved through Tiny township, north Midland, Penetanguishene and Victoria Harbour. This storm brought a major cloud lowering over Midland, and hail that ranged from quarters to tennis ball sized hail, which was reported in Penetang.
A second supercell formed behind the first again near Collingwood, taking a more southerly trajectory than the first one. It affected Wyevale through Waverly and moved northeast through to Waubaushene before moving into Cottage Country. A tornado warning was issued on this storm as it had strong rotation on it. This storm again produced large hail and had the look of a classic supercell.
I also saw the storm was also rotating quickly just west of Waverly, which I recorded on my camera.
This storm produced half dollar to ping pong ball sized hail along its path, which was reflected by storm pictures that I observed in Waubaushene as well as video from the area. It also produced a rainbow on the back edge of the storm.
One final supercell formed to the south of Collingwood and tracked northeast just north of the Barrie area, and affected Oro-Medonte and the Orillia region. This storm produced hail ranging from half dollar to ping pong ball sized as well before dying out northeast of the city.
Finally, just before 6pm, the cold front finally moved through Northern Simcoe County, bringing gusty winds, a shelf cloud, and plenty of thunder and lightning. These pictures were taken from Balm Beach.
This storm chase was exciting, especially given that all the storms were rotating and even more so because it was October and an unusual time to get severe storms. It truly was a crazy day and one to remember for a long time!