Forecasters say hot, dry weather in St. Lawrence County and the entire eastern United States may be close to doing a 180.

The National Weather Service is predicting stormy weather throughout St. Lawrence County, with rain starting on Sunday and thunderstorms Monday every day through at least Thursday.

Accuweather says this is due to an unusual weather pattern moving into the entire eastern United States that they predict could last through early August.

“A pattern of persistent downpours, beginning with a rainstorm this weekend, is likely to disrupt travel and hinder outdoor plans and projects and put summer heat on hold in much of the northeastern United States into early August. The pattern may escalate into a serious flood threat for some communities next week,” Accuweather said in a Friday afternoon email. “As AccuWeather long-range meteorologists have been suggesting since early July, the overall weather pattern will become conducive for rounds of wet weather and an increased risk of flooding in the Northeast.

“Such an extensive pattern of wet weather is highly unusual for the middle of summer, without a tropical storm,” according to AccuWeather Founder, President and Chairman Dr. Joel N. Myers.

In St. Lawrence County, NWS is calling for a mostly clear Friday night in the low 60s, a sunny Saturday in the mid 80s and a 30 percent chance of showers starting Saturday night with temperatures in the mid 60s.

NWS forecasts 60 to 70 percent chances of rain on Sunday with temperatures in the mid 70s, and 50 to 60 percent chances at night with temperatures in the mid 60s.

On Monday, NWS says showers and thunderstorms are likely in St. Lawrence County, with chances up to 80 percent and temperatures in the low 80s. High chances of showers and thunderstorms continue Monday night with temperatures dropping about 10 degrees.

NWS says showers and thunderstorms are just as likely Tuesday and Tuesday night, with temperatures at highs in the high 70s and lows in the low 70s.

The detailed forecast for the Potsdam area:

Friday night: Clear, with a low around 63. Calm wind becoming south 5 to 7 mph in the evening.

Saturday: Sunny, with a high near 86. Southeast wind around 7 mph.

Saturday night: A 30 percent chance of showers, mainly after 4am. Partly cloudy, with a low around 64. Southeast wind 5 to 7 mph. New precipitation amounts of less than a tenth of an inch possible.

Sunday: Showers likely, mainly after 8am. Cloudy, with a high near 76. Northeast wind 7 to 13 mph becoming southeast in the afternoon. Chance of precipitation is 60%. New precipitation amounts between a tenth and quarter of an inch possible.

Sunday night: A 50 percent chance of showers. Mostly cloudy, with a low around 67. South wind around 6 mph becoming calm in the evening. New precipitation amounts of less than a tenth of an inch possible.

Monday: Showers, with thunderstorms also possible after 2pm. High near 82. South wind 6 to 8 mph. Chance of precipitation is 80%. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.

Monday night: Showers and thunderstorms before 8pm, then showers likely. Low around 71. South wind around 8 mph. Chance of precipitation is 80%.

Tuesday: Showers likely, with thunderstorms also possible after 2pm. Mostly cloudy, with a high near 79. Southwest wind around 9 mph. Chance of precipitation is 70%.

Tuesday night: Showers and thunderstorms likely. Mostly cloudy, with a low around 70. Southwest wind around 7 mph. Chance of precipitation is 70%.

Wednesday: Showers likely, with thunderstorms also possible after 2pm. Mostly cloudy, with a high near 81. Southwest wind around 8 mph. Chance of precipitation is 70%.

Wednesday night: Showers likely and possibly a thunderstorm. Mostly cloudy, with a low around 66. South wind around 6 mph. Chance of precipitation is 60%.

Thursday: Showers and thunderstorms likely. Partly sunny, with a high near 82. Southwest wind around 7 mph. Chance of precipitation is 60%.

Thursday night: Showers and thunderstorms likely. Mostly cloudy, with a low around 63. Southwest wind around 6 mph. Chance of precipitation is 60%.

Friday: A 30 percent chance of showers. Mostly sunny, with a high near 82. West wind 7 to 9 mph.