Tornado watches, strong thunderstorm warnings have been issued in parts of North America

Powerful storms are sweeping through parts of the north country Thursday, leaving thousands of people without electricity. 

Especially hard-hit is St. Lawrence County, where there are numerous reports of downed trees, power lines, and trees on fire. 

The National Weather Service issued a tornado watch for Jefferson, Lewis, and St. Lawrence counties.  

The watch is in effect for the tri-county region as well as other areas of the state until 11 p.m. The watch means conditions are favorable for the formation of a tornado, not that a tornado is imminent.

The NWS also issued severe thunderstorm warnings for Jefferson, Lewis, and St. Lawrence counties, which expired at 5:45 p.m. The NWS said ping pong ball-sized hail and 60-mile-per-hour wind gusts were possible.

Once those warnings expired, the NWS issued similar warnings for Jefferson and Lewis counties through 7 p.m. Eastern St. Lawrence County has a severe thunderstorm warning in effect until 6:45 p.m.

At the height of the outages, nearly 8,100 National Grid customers in St. Lawrence County were without electricity. That was at 6:20 p.m.