A chilly but sunny weekend sets the stage for a...

A chilly but sunny weekend sets the stage for a snowstorm that could affect the Monday morning commute, forecasters say.

The first half of this week's weather forecast features two chances of snowfall, meteorologists said — and the first could make a mess of Monday morning’s commute.

Sunday's forecast starts as sunny with a high of 37 degrees. As clouds increase in the afternoon, "we're setting the stage" for a weak area of low pressure that's approaching Long Island, said Tim Morrin, a National Weather Service meteorologist in Upton. That low will probably bring snow, which is expected to begin around midnight Sunday, Morrin said.

The snow is expected to last until daybreak Monday, accumulating 1 to 2 inches but possibly up to 3 inches in some areas, Morrin said. Monday's morning commute could be impacted; the snow is expected to change to rain and freezing rain between daybreak and 10 a.m. with slightly rising temperatures.

After 10 a.m., the precipitation should taper off, though Morrin said some showers could linger through part of Monday afternoon. 

There is a slight chance of residual snow showers Monday night, but no accumulation is expected, Morrin said.

Tuesday will probably be cold and sunny with a high of 35 degrees. "At least it's dry," Morrin said. "It's sunny but chilly."

On Wednesday, there is a 30 percent chance of snow after 3 a.m., and the chance rises to 40 percent by daybreak, he said. Meteorologists don't yet know accumulation estimates, Morrin said. Snow could turn to a wintry mix or rain later in the day.

Wednesday's high is forecast for 35 degrees, he said, within the average range on Long Island for this time of year.

With Khristopher J. Brooks