Severe thunderstorm in Montreal - July 15th, 2016

***I recommend using earphones/headphones to hear the more natural sound of the thunder***
***Please watch in HD, if possible***

****Please feel free to view my Spring-Summer 2019 outlook here:

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A video compilation highlighting the severe thunderstorms that affected most of the island of Montreal, but especially the East end. Laval and closely surrounding locations also received the thunderstorm cluster particularly significantly, especially with the straight-line winds involved. Thunderstorms began to be seen during the early-afternoon, but the storms that affected the island were first seen in the distance by 5:35 p.m. Temperatures attained 29 C before thunderstorms affected the area. Severe thunderstorms occurred for a second day in a row.

Thunderstorms organized into a small line that produced a very defined shelf cloud to the NW. Thunderstorms formed ahead of a passing primary cold front (the first cold front was involved with the late-evening thundersstorms the previous day), along with additional lift supplied by favorable positive vorticity advection associated with a shortwave trough. In addition, there had been significant jet stream divergence due to a jet streak. Due to copious solar heating earlier in the day, low-level lapse rates became steep, and the line formed within a narrow zone of mid-level lapse rates of 6 C/km to the NW. Dewpoints were 17-18 C before and during thunderstorm initiation. SBCAPE/MLCAPE were both on the order of 500-1000 J/kg. Shearing profiles were largely unidirectional (weak boundary layer helicity, partly due to modest moisture transport at the 850 mb level), and dry mid-level air, which helped to increase the risk of strong convective gusts and small to medium-sized hail (which was observed in sections of the East end).

Footage was taken in SW Pierrefonds, located in Montreal’s West Island.

Thank you for your viewing.

~Trav.~