We are finally coming to the end of this intense heat wave that has gripped southern Ontario since temperatures started rising on Sunday.  A cold front is expected to arrive tonight from the north, bringing with it thunderstorms as the cooler air collides with the hot air mass.  Because of this expected stormy weather, Air Canada has issued a travel alert for passengers scheduled to fly out of Toronto’s Pearson International Airport today.  Air Canada and Air Canada Express flights operated by Jazz could be disrupted because of the thunderstorms.  The airline has revised its ticketing policy for customers booked on affected flights to facilitate changes to bookings. Customers wishing to make alternative travel arrangements can do so without penalty.  Passengers are also advised to check their flight status or call Air Canada’s automated flight information system prior to leaving for the airport.  All the information is online at aircanada.com.