If you live in Halton, Peel, Vaughan, Richmond Hill, Newmarket or northern York Region, watch the skies. They could contain a nasty surprise.
Environment Canada has issued a tornado watch for a large area surrounding the G.T.A., although Toronto isnt on the list.
The advisory doesnt mean there will be twisters coming down, only that two fronts are colliding in the atmosphere above us, creating the possibility that such activity could occur.
Other cities covered by the watch include Kitchener-Waterloo, Barrie, Orillia, Guelph, Cambridge and Orangeville.
Some O.P.P. officers up north have already reported sightings of a twister, but the weather office hasnt been able to confirm any funnel clouds.
The city itself is facing a severe thunderstorm warning, with the chances of heavy downpours and potentially damaging winds gusting up to 90 kilometres an hour. Large hail is also a possibility.
The unsettled weather will remain until at least Saturday and will be accompanied by an old friend high humidex values.
The first day of the weekend promises a return to the sticky conditions, with temperatures near 30C feeling closer to 40. And if you thought Friday was loud, just wait.
There is a weak cold front coming through and the air mass we're in is very, very humid, moist, and unstable, explains CityNews Environment Specialist Harold Hosein. So the collision between the two air masses is producing this first set.
"[Saturday] is likely to be a little more active, more widespread and more intense because there is much cooler dryer air to the west side of this system and a bigger collision will occur tomorrow afternoon.
Much of the G.T.A. woke up to the sound of thunder early Friday and most of the bad weather is expected to hit when you want it least during the height of the rush hours.
At least 35-45 millimetres of rain could fall between now and Saturday.
And while we certainly need the rain, we may not have wanted it on one of the last remaining weekends of the summer.
The C.N.E. opened Friday, and in some rare bad luck, its first day came amid some drenching downpours.
But Harold notes while most of the activity will be unpleasant and could create the usual traffic nightmares, for most of us it will be simply an inconvenience.
I would be a little bit concerned for those who might be in camping grounds or anybody trying to go out onto a sporting field, he adds. That's not a good idea.
Things will clear out by Sunday, when it will be noticeably cooler, with a mix of sun and cloud.
dooooom.