Supercell Thunderstorm in Montreal - June 28th, 2010

A powerful squall line associated with a vigorous cold front advancing in from the Northwest (NW) at roughly 30-40 km/h brought with it a line of strong thunderstorms and heavy rainfall. Thunder and lightning were also witnessed as well as strong gusts of wind approaching 80 km/h. Before the storm came, from a distance, large scud were developing from beneath the shelf cloud, which provided some indication of the strength of the downdrafts. There was some distinctive lowering as well, suggesting rotative motion within the updraft areas of some of these storms - the most distinctive signatures can be detected between 3:00-5:20 of the video. I will attempt to incorporate a time lapse to fully visualize and appreciate the rotation of this storm.

Two tornadoes were confirmed by Environment Canada with this squall line, one of which was in Saint-Anne-de-Bellevue (8 km Southwest of where I reside) and one just to the North of Montreal. Both tornadoes were registered at F0 strength (the weakest). Though at the lowest end of the Fujita scale, winds are clearly powerful enough to do some damage to trees (some large) and property.

~Trav.~

Category:

Entertainment

Tags:

• Severe
• Thunderstorm
• Tornado
• Supercell
• Rain
• Hail

[VideographyOfStorms]

After reviewing this video more I do believe that you were filming some rotation. You could of time lapsed this video like it is and you will pick out that rotation easily. Amazing Storm Structure! You did a very good job! I really mean that!

[Rain1290]

Hi Nathan,

Indeed, there are clear indications of an active mesocyclone(s) within these storms. I recall noting several points of possible rotation at the time. It would be a wonderful idea to time lapse this video to truly appreciate the rotation signatures - perhaps YouTube's Video Editor possesses the function that I require.

In any case, Nathan, thank you again for your good observations, and I appreciate the good comments! I am pleased that you liked the video.

~Trav.~

[uragan97]

great storm

[Rain1290]

Hi Nathan,

The area of the storm where the most distinctive rotation was pronounced stayed to our SW - the line of storms principally moved in from the NW and headed SE. There was, however, one tornado occurrence eight kilometers SW of where I live towards the Southern tip of Saint-Anne-de-Bellevue, where trees were down and minor damage was dealt to some homes in the area. No injuries were reported, thankfully. :)

Thank you for your comment, Nathan!

~Trav.~

[VideographyOfStorms]

@Rain1290 I agree between 4:00 - 5:00 that the the storm structrue shows evident rotation. When the storm was at a distance it caught my eye and so I started to review the video over and over again. Towards the end of the video the storms rotation went right over you didn't it? I enjoy observing other peoples storm videos and it really brings up good discussion which is awesome!

Congrats to you on the great storm capture once again!

Nathan

[Rain1290]

Hi Nathan,

I just made the necessary additions to the video information and its title once I re-examined the storm structure and its attributes (namely the parts that you took the time to analyse). In the end, this certainly qualifies as being a supercell thunderstorm.

I will see what I can do as far as making a time lapse. :)

~Trav.~

[Rain1290]

Thank you!

Yes, the shelf cloud was very well defined in a nice elongated, curved dark band of cloud, and you could see that the large scud were exhibiting movement that suggests some rotative motion within the storm's updraft.

That was a great Summer evening for me, and the start of what appeared to be a unique storm season ahead.

Thank you again for your comment, Nathan!

~Trav.~

[Rain1290]

Hi Nathan,

Looking back at the piece of this video that you make reference to, I believe you are correct. At the time, I was certain that there was at least some mild rotation with some of these multicell thunderstorms, but reviewing parts of the video, especially between 4:00 - 5:00, I also observe that the rotative signatures were much more distinct - these feelings were confirmed when I later discovered an F0 strength tornado 8 km SW of my residence.

Thank you for your input!

~Trav.~

[VideographyOfStorms]

2. I know that you notice the rotation too, but you can really see it as you drag the video player along. Before I started watching this video I could tell that the storm was rotating by the storm structure the nice swirl appearance it had.

If you drag this video from 4:15 slowly to 4:35 there is great indication of rotation. I just had to dissect your video Travis. : )