A cold front pushed through the Pioneer Valley this afternoon and is now moving offshore this evening. Much cooler air is beginning to transfer into the region and we are in for a cold overnight. Expect low temperatures to range from 34 to 39 degrees. The evening clouds will give way to clearing skies later tonight with light north winds.
The National Weather Service has issued a Frost Advisory for Berkshire, Franklin, Hampden and Hampshire Counties for later tonight through about mid morning Tuesday. If you have any tender potted plants outside you may want to bring them inside for tonight and again tomorrow night.
A large high pressure system, centered over the Great Lakes this afternoon, begins to edge its way into New England later tonight and Tuesday. Expect an Autumn like day on Tuesday with high temperatures only 60 to 64, despite generally sunny skies. Another chilly night will be in store Tuesday night with clear and calm conditions. Lows may touch 32 in some spots to about 38 in Springfield. Generally a light north to northeast wind Tuesday, dropping off to calm at night.
As the high pressure system moves southeastward it will be centered just to our south by Wednesday morning, shifting further south during the day. This will set up a southwest air flow and that means milder temperatures. The theme for the remainder of the week will be dry and pleasant weather with a moderating trend Wednesday through Friday. Bright sunny days will help drive the mercury to highs of 68 to 73 Wednesday, 73 to 78 Thursday and Friday. Overnight lows near 45 Wednesday climbing to about 55 Friday night.
These roller coaster temperatures are not unusual for this time of year as we transition from Summer to Autumn. This week will feature a perfect example of this with the cold temperatures the next couple of nights, along with a cool day Tuesday, some 10 degrees or so below normal, before temperatures climb well into the 70s again toward the end of the week.