Coastal storm could bring snow to Boston on Friday. Here’s how much. – The Boston Globe

It may actually begin to look a lot like Christmas, at least for a moment to kick off the weekend before the busy holiday week.

We’ve mentioned an offshore system developing Friday a few times this week, but a separate system to our west will dive just south of New England as the coastal storm develops. Why does this matter? Well, that incoming storm may tug or influence the coastal low, forcing the system to drift closer to the Southern New England coast. This could bring some rain and accumulating snow for Boston and other parts of coastal New England Friday into Saturday morning.

There’s still uncertainty as to how much the two storms will interact and that will determine the final storm track. But should the coastal low push west enough to clip the coast, we should only see relatively weak impacts and perhaps just some festive light snow showers as you’re out in the city Friday evening or shopping Saturday morning.

It’s looking like some light rain and snow showers will begin working into Southern New England and the Boston area mid-afternoon on Friday and bring light to steady precipitation throughout the evening. Like a similar storm last week, wet weather will enter the picture from the south and be supported by additional moisture blowing onshore from the east. At some point Friday night, the wind direction will shift to the northeast as the core of the storm passes offshore, making this storm technically a nor’easter.

Just like a similar system last week, the storm will strengthen as it passes and therefore race out of the region. By Saturday morning, between 6 a.m. and 8 a.m., this storm will be near Nova Scotia and clouds will be thinning for a dry weekend.

Temperatures will be in the mid-30s from Worcester to Boston Friday afternoon with Southeastern Mass. and the Cape closer to 40 degrees. With some added warmth blowing on shore, that’ll make it even trickier to set the rain-snow line and those areas could start off with rain.

I’d say that I-495 and east to Boston, south to the Cape, will start with cold rain before quickly switching to light snow showers as the temperatures drop heading into Friday evening. Western New England won’t see much action with this storm outside of a few flurries at times.

A switch to snow from the Boston area to south coastal areas should happen fairly quickly and really only the outer Cape will stick to rain.

All in all, it’s looking like light accumulations from a coating to 2 inches, with the higher totals happening around the I-95 and I-495 belts. There could be a heavier pocket of snow that pushes an isolated 3 inches in a couple of spots.

Outside of Southern New England, Downeast Maine will be clipped by the outer edge of this storm, where Bangor to Millinocket might snag about 4 to 6 inches.

This storm will strengthen as the evening progresses and wind gusts will reach anywhere from 20 to 30 miles per hour for folks along the coast. The blustery conditions will likely stay in place Saturday after the storm passes.

The main question is: If it does snow more than an inch in Boston, will it be enough to stick around to count as a white Christmas come Wednesday morning? We’ll keep you posted.

Ken Mahan can be reached at ken.mahan@globe.com. Follow him on Instagram @kenmahantheweatherman.