Saturday, December 08, 2007

Wintery Mix: December 9-10

Here is my first and probably final call for the storm system moving in tomorrow afternoon and evening. The precip will move in from west to east and will probably start as snow for everyone, but quickly transition to rain/mix on the Cape and South Coast. Further north of there, in the pink shaded region, there will be more of a mixture of snow/sleet, but freezing rain will be the big player here with over a 1/4" ice accretion possible. I would not at all be surprised to see Winter Storm Watches hoisted for this region later on for the ice. More likely Winter Weather Advisories by tomorrow morning, though, for a majority of SNE. In the pink region, there is the chance of about 1" of snow before the flip to freezing rain. Here, by the Monday morning AM commute, temperatures may come up above 32, but that may be pushing it as many mets believe that the GFS and NAM are overplaying the warm air and that the cold will be much more stubborn to let go. In the blue region, we will see more snow from this before we think about a changeover. A solid 1-3" of snowfall is possible, maybe more if this area can stay mainly a snow event. Where it does stay mainly snow, mainly north of the Pike and away from Rt. 128 and the coast, 2-4" is likely with some spots in northern Worcester County maybe getting closer to 5-6", tops.

There is a wide model discrepancy between the NAM and GFS this afternoon, however. GFS paints lots of snow, north of the Pike and a good amount south, but the NAM doesn't give anyone in SNE more than an inch or two, so you can see this is a high stakes, low confidence forecast. A forecast that will likely change. I played it in the middle. Either way, the Monday AM commute is going to be messy with more delays and cancellations likely again.

More on this forecast tomorrow with any advisories, watches, or warnings underway.

No comments: