Governor Kathy Hochul announced a State of Emergency Thursday morning for St. Lawrence County and 10 other counties as a winter storm is forecast to impact portions of upstate New York with intense lake effect snow through Sunday.

Up to 10 to 21 inches of snow are possible in parts of St. Lawrence County by Saturday night, according to the National Weather Sesrvice.

The most significant snowfall is expected tonight and Friday with with up to two feet or more possible in the Watertown area, but St. Lawrence County is not expected to escape the storm.

Hazardous travel conditions and local power outages as a result of the storm are likely due to the combination of snow and wind in the forecast, Hochul said. Lightning and thunder may also occur in the heavier, more intense bands. Hochul urged New Yorkers to stay alert and avoid unnecessary travel through Friday, particularly in the Buffalo and Watertown areas.

In the Gouverneur area, snow showers are likely overnight, mainly between 3 am and 4 am, then snow after 4 am. The snow could be heavy at times. New snow accumulation of 1 to 2 inches possible, according to the National Weather Service.

Friday, snow could be heavy at times with accumulation of 9 to 13 inches possible, the weather service says. Friday night, snow could be heavy at times with accumulation of another 3 to 7 inches possible.

Saturday, there is a 50 percent chance of snow showers with accumulation of around an inch possible. A chance of snow showers continues before 1am Saturday night, then snow after 1am.

Here’s a look at the National Weather Service forecas for the Potsdam area:

Tonight

A slight chance of snow showers between 3am and 5am. Increasing clouds, with a low around 20. Southwest wind 5 to 7 mph becoming calm after midnight. Chance of precipitation is 20%.

Friday

A chance of snow showers between 7am and 11am, then snow likely after 11am. Cloudy, with a high near 36. Southwest wind 6 to 13 mph. Chance of precipitation is 70%. New snow accumulation of 3 to 7 inches possible.

 Friday Night

A 50 percent chance of snow showers. Mostly cloudy, with a low around 26. South wind 6 to 9 mph. New snow accumulation of 1 to 2 inches possible.

Saturday

A 40 percent chance of snow showers. Mostly cloudy, with a high near 34. South wind 8 to 14 mph. New snow accumulation of less than a half inch possible.

Saturday Night

A chance of snow showers before 1am, then snow likely after 1am. Mostly cloudy, with a low around 22. South wind 10 to 13 mph. Chance of precipitation is 60%.