Low pressure lifting out of the Midwest today will cross eastward over the Great Lakes tonight and pass through New England Sunday morning. This weather system will spread a shield of precipitation into the region late this afternoon and tonight, resulting in a period of accumulating snow.
Low pressure passing north and west of New England is never a big snow producer for our area (and won’t be this time around either). The counter-clockwise flow of air around low pressure ensures that a storm passing to our northwest drives a southerly wind into area. Those southerly winds transport warmer air into the region and typically result in a rather rapid transition from frozen precipitation to liquid.
While a flip to rain is almost a guarantee this go around as well, the air mass heading into this particular storm is very cold and dry (temperatures in the 10s this morning) and will take quite some time to scour out (a light wind through the day will help keep the surface cold in place). Consequently, as precipitation overspread this area this evening, it will certainly be in the form of snow and will persist for several hours before a mix with or changeover to rain occurs…likely accumulating to 1 to 3 inches around the Cape.
Thanks to the recent surge of cold air, the snow will accumulate/stick to all surfaces easily, meaning area roadways are likely to be slick and snow-covered for a time tonight…so anticipate some tough travel during the first half of Saturday night.