Winter storm warning in effect for part of Mass.: Heres what to expect

The National Weather Service has upgraded a winter storm watch into a warning for the Northern Berkshires, while a firmer sense of how much snow Massachusetts could see Friday is taking shape.

The agency issued a winter storm warning for Northern Berkshire County, effective from 4 p.m. Thursday through 10 a.m. Saturday.

Although much of the state is still expected to see a snow/rain mix with no accumulation in Eastern Massachusetts and little in Central Mass., the higher elevations in Western Mass. are expected to get accumulating snow.

Heavy snow is expected in that area with forecasters currently estimating 12 to 18 inches of snow.

Travel could be very difficult to impossible, the National Weather Service reported for the area of the storm warning. The hazardous conditions could impact the morning or evening commute.

The agency also added a winter storm watch for Southern Berkshire County and a watch for Western Franklin, Western Hampden and Western Hampshire counties. A possibility of 4 to 10 inches of snow exists there, but the agency is expected to have a better idea on Thursday as the storm draws closer.

With temperatures shifting forecasters continue to watch this storm closely for any updates or adjustments to the forecast. The biggest areas in question will be just east of the Berkshires from Springfield northeast, where if that snow doesnt turn to rain quickly, accumulated amounts could shift.

A significant storm is expected to impact New England Thursday night into early Saturday, the agency said. Snow will be heavy, wet, and heavily dependent on elevation.Timing and impact

Rain and snow should hold off until Thursday evening, the weather service reported, and could also linger through Saturday morning.

By 7 a.m. Friday, forecasters have high certainty that the Northern Berkshires will have had 3 to 7 inches of snow already.

The agency expects precipitation to wind down from west to east during the day Friday.

There could be a brief final burst of snow across the higher elevations when the colder air surges south, it said. Type of snow

The National Weather Service reports most of the snow will be heavy and wet with only dryer snowfall at the highest elevations in the Berkshires. Possibility of more snow

MassLives interactive snow map is showing a potential for 12 to 14 inches in the Berkshires with 2 to 3 inches in Springfield and 3 to 4 inches in Worcester. Those are the areas to watch closely as this storm nears as they are on the edge and could see higher accumulations or, if warmer temperatures prevail, could transition to rain sooner, meaning less snow on the ground.

MassLive will have updated forecasts and predictions as the weather event draws closer Thursday.