Hot and humid weather is expected across the St. Lawrence Valley this weekend with heat advisories in place, according to the National Weather Service (NWS).

High temps today will push 90 with heat index values as high as 94, forecasters predict.

A few showers and thunderstorms may form

this afternoon and again on Sunday but should be very limited in coverage, NWS says. Overnight will only drop down to around 73.

A high of 86 and heat index values of 93 are expected on Sunday.

A strong cold front is expected to enter the region on Monday bringing periods of heavy rain to Northern New York, the service says.

The extended forecast through next Friday is as follows:

Sunday

A 40 percent chance of showers and thunderstorms, mainly after 1pm. Mostly sunny, with a high near 86. Heat index values as high as 93. Southwest wind 9 to 13 mph. New rainfall amounts of less than a tenth of an inch, except higher amounts possible in thunderstorms.

Sunday Night

A chance of showers before midnight, then a chance of showers and thunderstorms between midnight and 1am, then a chance of showers after 1am. Mostly cloudy, with a low around 63. Southwest wind 5 to 8 mph becoming light and variable after midnight. Chance of precipitation is 50%. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.

Monday

Showers likely, mainly after 11am. Mostly cloudy, with a high near 73. Northeast wind 5 to 7 mph. Chance of precipitation is 60%. New precipitation amounts between a quarter and half of an inch possible.

Monday Night

Showers likely. Mostly cloudy, with a low around 59. Northeast wind 3 to 6 mph. Chance of precipitation is 60%. New precipitation amounts between a quarter and half of an inch possible.

Tuesday

Showers likely, mainly before 9am. Partly sunny, with a high near 73. Northeast wind 3 to 8 mph. Chance of precipitation is 60%.

Tuesday Night

A 30 percent chance of showers before 9pm. Partly cloudy, with a low around 59. Northeast wind 5 to 7 mph becoming calm in the evening.

Wednesday

Mostly sunny, with a high near 78. Calm wind becoming west around 6 mph in the afternoon.

Wednesday Night

Partly cloudy, with a low around 60. Southwest wind around 7 mph.

Thursday

Mostly sunny, with a high near 76. West wind 3 to 8 mph.

Thursday Night

Partly cloudy, with a low around 55. North wind around 6 mph becoming calm in the evening.

Friday

Sunny, with a high near 73. North wind 6 to 8 mph.