Metro Boston, north shore and western suburbs: A cold front approaches from the west today with low pressure developing along the front to our south. This low will be responsible for the rain and snow in the area through the day as it tracks along the New England south coast quickly exiting the area early tonight. Another weak disturbance will move out of the Ohio Valley early Sunday and rapidly move toward New England during the day.
Our weekend is going to feature considerable cloudiness and periods of light precipitation. Saturday will be the cloudier day with the greater risk of light rain or snow. It should be mostly rain along the coastal plain, with a mix west of Route 128/95 transitioning to mainly snow west of Route 495. The National Weather Service has posted a Winter Weather Advisory for northern Middlesex County and through most of central and north central Massachusetts until 7 pm this evening where 2 to 4 inches of snow could fall, highest amounts across the higher elevation. Also, the advisory extends across the border into southern New Hampshire and points north, so if you are traveling in either of these areas today expect to go from a rain or snow and rain mix to all snow. There could be a slushy inch or so of accumulation along the Route 128/95 belt, but along the coast it is doubtful any accumulation occurs although a change back to snow in late afternoon and evening could put down a coating before the precipitation ends.
As the low pulls away we dry out overnight as the winds pick up and colder air begins to transfer across the area on the backside of the low. Expect a colder and blustery night.
The next impulse for Sunday keeps us mostly cloudy with a chance for snow flurries or snow showers. This system will rapidly move out Sunday night with another push of colder air following in behind it.
Martin Luther King Day should see a mix of clouds and sun, cooler and breezy. Another in a series of cold fronts moves through during the day. Colder air will continue to overspread the area through the day and overnight is when we begin to fall back into the freezer as temperatures really cool down.
Winter makes a big time comeback for the remainder of the work week. It turns very cold Tuesday and Wednesday as the arctic air takes a firm hold on the area and keeps us uncomfortably cold into Thursday as well. Fair skies rule Tuesday and Wednesday, with a chance of light snow Thursday as low pressure approaches. As for temperatures highs in the teens to near 20 Tuesday and Wednesday, overnight lows in the single digits both Tuesday night and Wednesday night.
72 Hour Outlook:
Saturday: Periods of light rain along the coastal plain, possibly mixing with snow at times. Mix inland to all snow along and west of Route 495. Precipitation could change to all snow everywhere later this afternoon and evening before ending. High temperatures in the low to mid 30s well inland to near 40 on the immediate coast. Light north to northeast winds. Snow accumulations 2 or 3 inches northern Middlesex County, possibly a few 4 inch totals, ranging to maybe a coating along the coast by evening.
Saturday night: Precipitation ends early followed by a mostly cloudy overnight. Lows taper back to the mid 20s interior to 30 on the coast. West winds 5 to 15 mph.
Sunday: Blustery and cooler, chance of a snow flurry or few snow showers, especially inland. Considerable cloudiness. Highs in the mid 30s. Gusty west winds.
Sunday night: Generally partly cloudy, cooler and windy. Lows near 20 well inland to upper 20s on the coast. Gusty west winds continue.
Martin Luther King Day/Night: Partly cloudy and becoming much colder overnight. Highs in the low to mid 30s. Overnight lows in the low teens.