The National Weather service says precipitation and decreasing temperatures could lead to snow this week in central and southern St. Lawrence County.

Meteorologists are calling for a mostly cloudy Wednesday night with temperatures in the high 30s leading to a 40 percent chance of showers Thursday with temperatures in the high 50s.

There is a 70 percent chance of showers Thursday night with temperatures in the low 40s, giving way to a 50 percent chance of rain Friday with 40 percent odds at night. Friday temperatures are predicted to go from the low 50s to mid 30s.

The NWS says rain and snow is likely Saturday, with 50 to 60 percent odds in Canton, Gouverneur, Potsdam and Star Lake. Massena and Ogdensburg are looking at a 40 percent chance of showers. Temperatures countywide are predicted to hit a high of 44 degrees.

The detailed forecast for Potsdam:

Wednesday night - Mostly cloudy, with a low around 38. West wind 5 to 9 mph becoming calm in the evening.

Thursday - A 40 percent chance of showers, mainly after 10am. Mostly cloudy, with a high near 59. Southwest wind 7 to 15 mph. New precipitation amounts of less than a tenth of an inch possible.

Thursday night - Showers likely. Cloudy, with a low around 42. Southwest wind 5 to 9 mph. Chance of precipitation is 70%. New precipitation amounts between a tenth and quarter of an inch possible.

Friday - Showers likely, mainly before 9am. Mostly cloudy, with a high near 52. West wind 8 to 10 mph. Chance of precipitation is 60%. New precipitation amounts of less than a tenth of an inch possible.

Friday night - A 50 percent chance of showers. Mostly cloudy, with a low around 36. Light west wind. New precipitation amounts of less than a tenth of an inch possible.

Saturday - Rain and snow showers likely before 9am, then a chance of rain showers. Mostly cloudy, with a high near 44. Northwest wind 7 to 10 mph. Chance of precipitation is 60%. New precipitation amounts between a tenth and quarter of an inch possible.

Saturday night - Partly cloudy, with a low around 28. Northwest wind 6 to 9 mph.

Sunday - Mostly sunny, with a high near 42. Northwest wind 7 to 9 mph.

Sunday night - Partly cloudy, with a low around 28. Northwest wind around 6 mph.

Monday - Mostly sunny, with a high near 44. West wind 3 to 7 mph.

Monday night - Partly cloudy, with a low around 36. South wind around 8 mph.

Tuesday - Partly sunny, with a high near 56. Southwest wind 11 to 15 mph.

Tuesday night - Mostly cloudy, with a low around 46. South wind around 11 mph.

Wednesday - Mostly cloudy, with a high near 60. Southwest wind 11 to 13 mph.