The watch also covers the Finger Lakes, central and northern NY, northern Pennsylvania and part of Vermont.
A tornado watch means conditions are favorable for severe thunderstorms, including the possibility of tornadoes.
A line of severe thunderstorms will march eastward across Pennsylvania later today, threatening to trigger damage and delays into Tuesday night. Severe thunderstorm warnings and tornado warnings will be issued for individual severe storms as they happen.
We are tracking a strong cold front diving into the region on Tuesday.
In the event of a tornado, Environment Canada recommends going indoors to a room on the lowest floor, staying away from outside walls and windows, and leaving free-standing shelters to move to a stronger building if possible.
The National Weather Service canceled a Tornado Watch for all of Western New York.
Also being watched closely is an area of rain and thunderstorms located near the Yucatan peninsula, the remains of former Tropical Storm Harvey. Winds between 50 and 60 miles per hour were also possible.
This is the leading edge of cooler and drier air that gradually moves into New England over the next few days.