This is an email I got from Phil Brown...a rigid wing pilot living in Windsor that almost came to the Arizona meet I'm heading to next week.
A little correction would be that it is not truck towing, but stationary winch towing. Here is a picture of our winch.

I have to say that I am a newer pilot and am learning more about weather patterns here. Lake Erie and St. Clair shutdown a lot of thermal activity on certain days, and may create a lot on other days.....not sure yet. Post-frontal (NW) days are great. I have however seen phenomenons that are mighty curious.
Mid June last year a convergence set up over our tow field that was maybe a mile wide. (the clouds that is) It was so over our field that the wind direction kept switching 180 degrees. By the time we figured out what was going on and one of the gliders got trashed in the switching wind (tie down the gliders!), we did not feel much like flying anymore. Had we just been patient and waited for a good cycle and not tried to chase the wind we would have got great flights. I remember looking at a sailplane fly from the west horizon to the east horizon without turning. It did this for one whole week. Work and fear got in the way of flying.
The sea breeze sets up on SW days in the summer almost everyday about 15 miles north of our field. I think it is a convergence of St. Clair and Erie. I don't know exactly????
You have to understand, when I say field I really mean my Dad's farm lane way. When the corn is in in the summer we are shutdown. Wheat fields are good. They come off early. I am getting more and more contacts and permission to fly on others property. I just got back from FL and had 12 hours of airtime in one week, and my first 25 mile XC. This is more than I usually get all summer.
I have 60 hours airtime and over 300 takeoff and landings. Understanding the area and being at the correct place are key. Most of the time my Dad's farm is on the stable side of the sea breeze. I too, hope to do some big XC's using this convergence one of these years. Till then I am studying the area to see what is possible. I would be fine flying with others, but my wife is having our 2nd child in July. I too, have a 2 year old. It kills the flying. Meanwhile, I am having fun learning the area.
On another occasion I was down at the lake playing golf. I noticed the sea gulls on a no wind blue day flying 800-1000 feet in the air soaring the beach without flapping. There isn't a bluff and I have no idea what variables make this situation happen. I can not even venture a guess. To me there is a lot of flying/weather mystery's to figure out in the area. Those darn two lakes. I don't know yet whether to love them or hate them.
Keep in touch,
Phil

The coordinates of where
The coordinates of where they tow from are:
N42 03'55.70
W82 32'52.89