I have heard and read several comments in regards to the report of an alleged “Lake Effect Tornado” in Goderich, Ontario, Canada yesterday (8/21/11). As a Storm Chaser, I’m quick to question and analyze reports anyway, especially when relayed from the general public. I’m here to offer my in depth analysis about this alleged “Lake Effect Tornado”
The SPC had a General T-Storm Risk issued. A decent upper level low was moving across the upper Great Lakes and southern Canada region. Near and ahead of this feature a chance of thunderstorms existed. Severe weather wasn’t anticipated, but anytime you get storms developing near a low pressure system with decent instability, it’s a possibility. A few thunderstorms had fired in the northern lower peninsula of Michigan, around the Straits of Mackinac. I closely monitored these on both GRLevel3, and the SPC’s Mesoanalysis page. Nothing seemed out of the ordinary, until the one parent cell on the southern end of a small cluster started running into some more favorable conditions. I tracked this thunderstorm southeastward through the northeast lower peninsula, until it became tornado warned in Alcona and Iosco counties. Both of which border the Michigan side of Lake Huron. Below is a compilation of 7 radar images taken from the SPC’s Mesoanalysis page on 8/21/11. I have circled the storm in question so it’s easier for you to identify it. The storm popped up in Emmet County, MI. Click images for larger view, left to right order.
SBCAPE was on the order of 1500j/kg, no CIN, Low Level Lapse rates between 6 and 7C/km, and SB Lifted Index steady at -3 to -4. The main teller for me was the Effective Bulk Shear climbing into the 45-50kt range ahead of a jet streak at the 300mb region. I included images of Effective Bulk Shear and the 300mb Jet Circulation below. Click images for larger view.
So as you can see, the conditions were ripe for t-storm development, and with the associated low pressure providing extra instability, and helping to aid a mixed wind field, I’m not surprised this cell became so strong. This was a relatively long track supercell with the upper level support present. If Lake Huron did have anything to do with it, the only thing I can think of is the open water may have provided a less interrupted wind field at the surface and mid levels, which allowed better organization to take place. This was in no way shape or form a Lake Effect Tornado. The only mistake in thinking it was, would be if this tornado began as a waterspout before moving on shore. Which is entirely possible that this tornado began as a waterspout considering the impressive hook echo on radar. The supercell that spawned the tornado also created an outflow boundary that moved southward away from the storm, further mixing the wind field. In closing, this was not a Lake Effect Tornado, but still an impressive storm, that did a lot of damage. Below are videos of the damage. Also a video of what appears to be some of the outer edges of the tornado itself. They may be laughing, but they could have been killed standing there. Canada unfortunately does not have a warning and safety system such as we do here in the US as tornadoes aren’t as common. Strong tornadoes are even less common. Hopefully this event gives a jump start to improving safety and learning about tornadoes in Canada. Click Here for a news article.