Forecast: Cool tonight, warm and rainy Monday

A cool, cloudy Sunday night will give way to a warm, rainy Monday, when temperatures are expected to creep close to 70 degrees in Nassau and western Suffolk counties, according to the National Weather Service in Upton.

Tonight's temperature will bottom out in the lower 50s and tomorrow will begin partly sunny, said John Murray, a meteorologist with the weather service. Thunderstorms will be possible in the late afternoon, he said.

Maximum temperatures on Long Island will hover in the high 60s, Murray said. By Monday night there will be an 80 percent chance of showers, he said.

"It'll be cooler by the twin forks," he said.

The warmth comes after chilly temperatures Friday and a Saturday that had close to normal readings, meteorologist David Stark said.

Seventy degrees is about five degrees above normal, Stark said. - With Jennifer Sinco Kelleher