With October winding down, winter is gearing up, with the first noteable winter storm of the season expected to grace the area on Saturday and Saturday night.
An upper-level trough will spawn a surface low pressure system off the Carolina coast, which will intensify as it charges northward along the eastern seaboard Saturday. The low will track very close to the coastline and spread precipitation into southern New Hampshire beginning Saturday evening, which will continue through the night, exiting rather quickly by late Sunday morning. In fact, skies will clear and the sun will most likely emerge by Sunday afternoon.
At this time, it appears precipitation will commence as purely rain late on Saturday, with high temperatures breaking into the lower 40s. Rain will continue after sunset, and will gradually change over to snow as temperatures recede through the 30s and the low draws closer. The snow will be slow to accumulate on the wet and warm roads, but will be quicker to on cooler on grassy surfaces. In addition, winds will pick up out of the north-northeast, with gusts possibly approaching 30 mph Saturday night.
Snow will mix with rain once again during Sunday morning, before coming to an end as purely rain during the late morning hours. The heavy wet snow accumulating on trees and powerlines could possibly result in localized downed trees and subsequent power outages. The most significant impacts on travel will be visibility, which could be reduced to one-quarter of a mile or less at times on Saturday night. Otherwise, the early nature of the storm and relatively warm temperatures for a winter storm will not lead to significant accumulations on roadways, or even on grassy surfaces.
The National Weather Service (somewhat suprisingly) has issued a Winter Storm Watch, which is in effect Saturday afternoon through Sunday morning, due to the potential impacts the heavy/wet snow may have on the region. Nevertheless, as this is the first winter storm of the season, be sure to be prepared for possible impacts on travel plans.