Potentially heavy snow is in the forecast for next week, with lighter accumulations today and Sunday.

A cold and showery air mass is spreading across Western Washington this weekend that will bring the snow level to below 1,000 feet today and to near sea level on Sunday, according to the National Weather Service.

The temperature in Renton Municipal Airport at about 1 p.m. Saturday was 39 degrees.

The best chance for snow accumulations in the next 24 hours is in Snohomish County and into the Cascades, as much as three inches. Elsewhere, rain will likely fall.

However, on Sunday the air mass will become cold enough that snow accumulations could become widespread, with about an inch in Renton, according to the weather service.

Drier conditions will start Sunday night and into Monday and Tuesday. However, potentially heavy snow could occur on Wednesday and Wednesday night, with highs in Renton about 37 degrees and lows in the upper 20s. The chance for a mix of rain and snow will continue after that.

The weather service indicated Saturday it’s too early to forecast for sure where the heaviest snow will fall mid-week. But it’s suggesting that the weather break Monday and Tuesday is a good time to prepare for the potential for severe weather.