As a colder airmass drops in and stays for a while, a look back at January 2013 shows a mild month. The average temperature at MacArthur Airport was over two degrees above normal. The data is not striking, but it continues the streak, with a blip here and there, of above normal months that stretches at least a couple of years. Once again, precipitation totals were about half of the average amount, despite no immediate concerns of a drought. Snowfall was well below normal with only a couple of shots of light accumulation to start the calendar year.
Into this weekend, a trough sets up in the Northeast, bringing cold, Canadian air with it. Daytime highs will either struggle to 30 degrees or settle in the 30s right into next week. Being at the base of the trough (it looks like a "U" on a weather map, we're on the bottom of it), the weather pattern gets a bit active. This weekend, case in point. A clipper drops in from the west, stays mainly to our south, but may clip Long Island with snow Saturday night and Sunday.
The snow starts about midnight Sunday morning and continues on and off through Sunday afternoon. Quick bands of light snow will round the north side of the storm center. A burst of heavier snow is possible at any time, reducing visibilities and dropping a quick accumulation that will make roads quite slick. Total snowfall for the storm is about 1"-2" for Long Island. There doesn't seem to be a specific area that gets more snow, but there's also the ever-so slight possibility of mixing mostly on the South Fork.
Once this storm departs, the cold air remains with 30s in the day, teens and 20s at night. Another clipper may drop a light accumulation around the Tuesday night time frame.