The National Weather Service is warning that an early season winter storm will likely bring heavy, wet snow to much of coastal Maine Saturday night, Oct. 29 into Sunday morning, Oct. 30.

A winter storm watch has been posted for the southern part of the state, from Kittery to Eastport along the coast and as far inland as Farmington, Skowhegan and Bangor.

The storm watch — which means there is a “potential for significant snow, sleet or ice accumulations that may impact travel” — remains in effect from Saturday evening through Sunday morning.

The storm, according to the weather service, “has the potential to become a major Noreaster and may possibly produce heavy snows across parts of the area Saturday night.”

Although earlier forecasts had predicted the storm system traveling further to the south, the weather service is reporting as of Friday that “now all models are in agreement that a more northerly track is expected… .”

Precipitation is expected to begin falling as rain or a mix of rain and snow late Saturday afternoon. That precipitation is expected to change over to “moderate to heavy wet snow” Saturday evening and continue into Sunday morning. Total accumulation could be as much as 4 to 6 inches, and possibly as high as 8 inches in Washington and Hancock counties.

Forecast information on the weather service’s website describe the storm as a “rarely-seen pre-Halloween snowstorm,” as well as being a “major snowstorm for October standards… potentially record-breaking… .”

“Not only will this be the first storm of the season,” the weather service bulletin noted, “it is much earlier than normal… especially for the coastal plain.”

For trees that still have leaves on them, the wet snow will cause “appreciable excess weight” which will “likely result in tree damage and subsequent power outages,” according to the winter storm watch bulletin.

Although as many as 6 inches of snow may fall, the weather service warns that “just 2 to 4 inches of heavy wet snow” will be enough to bring down branches that still have leaves on them.

In addition, travel conditions are expected to be poor Saturday night, if the storm maintains its predicted track. A “burst of heavy snow” that night is expected to accumulate on roadways, resulting in slippery travel conditions.