Low pressure is taking shape over the Southeast tonight and is poised to make a run at southern New England on Sunday. The storm will move quickly up the Eastern Seaboard during Sunday and is expected to be positioned near Long Island Sunday evening. A lot of moisture and mild air will ride up the coast as the storm takes a track further east than was indicated Thursday and Friday, eventually moving across southeastern Massachusetts Sunday night and then taking aim at the Maritimes for Monday.
It was a very nice Saturday as temperatures climbed into the low and mid 40s throughout the valley. We were able to scour out the morning clouds and get a decent amount of afternoon sunshine. Well, the combination of sunshine and mild temperatures will not be seen in these parts anytime soon. Once the storm departs late Sunday night another pool of very cold air will begin to overspread the area Monday and it continues to get even colder New Years Eve and New Years Day.
As far as the upcoming rain event is concerned the precipitation should begin by early in the afternoon on Sunday. There could be some snow and or sleet mixed in through the hilly terrain, but essentially most of us see just plain rain. It becomes steady and then heavier toward evening. But, this is a fast moving system and the faucet shuts off around midnight as the storm streaks northeastward. Toward the final hours we could see a mix to snow, even a changeover to snow in the hills, before the precipitation ends. Rainfall could range from 1 to 1.5 inches, with the possibility of an inch or two of snow in the hills toward the end, perhaps several inches through the northern Berkshires. We could see some flooding of low lying areas and poor drainage locations during the height of the heaviest rainfall.
Monday, an arctic cold front moves through early in the day and the flood gates will be open for much colder air to drain into the Pioneer Valley on gusty west winds. Wind chills will be down in the teens.
A clipper system moves through the area on Tuesday bringing a chance for some flurries and snow showers. It will also deliver a reinforcing shot of even colder air for New Years Eve and New Years Day. Gusty winds will drop wind chills below zero New Years Eve.
Some are already talking about a storm late in the week. I will pass on that for now and bring more updated information on that potential by early in the work week.
72 Hour Forecast:
Tonight: A few clouds around, then increasing clouds after midnight. Cold, low temperatures in the mid 20s. Light southwest winds.
Sunday: Rain develops in the afternoon, may become heavy at times toward evening. Snow and sleet may mix in through the hilly terrain for a time. Highs mid 30s hills to near 40 greater Springfield. Light southeast winds.
Sunday night: Rain, possibly heavy at times early, possibly mixing with and changing to snow before ending around midnight. Lows in the upper 20s by morning. East winds 10 to 20 mph, backing to west after midnight.
Monday: Partly cloudy, cold and windy. Highs in the mid 30s. West winds gusting to 30 mph.
Monday night: Very cold under a partly cloudy sky. Breezy early at night. Lows tumble to the mid single digits to low teens. Northwest winds diminish to 10 to 15 mph overnight.
Tuesday and New Years Eve: Generally partly cloudy, periods of mostly cloudy skies in the afternoon and evening. Chance of flurries or snow showers into the evening. Very cold and windy. Highs only near 20 degrees. Lows mid single digits to 10 degrees.