Challenges... Say It Ain't Snow
Posted by Chris Lambert
Not that weather in New England is ever easy, but this storm coming up the coast will certainly present it's challenges. The biggest challenge may be figuring out how the snow/mix/rain set-up plays out.
Precip starts between 2-4PM for many, and that means a dry morning commute and lunch. The heaviest precip and wind occurs in the evening and overnight.
What I've noticed over the last few model runs is a track farther east. If that's the case, our wind stays more out of the NNE rather than going east, and that means colder weather gets locked in. It also means that dew point levels stay low. That's important because with dew points running near 20 and actual air temperatures tomorrow afternoon running near 40-45, a process called evaporative cooling can occur which allows rain to turn to snow. What happens is, the precip starts as rain, but as some of those rain drops evaporate into water vapor, the dew points go up, and the temp goes down. A spread of a dew point of 20 and temp of 45, likely meets in the lower to mid 30s when precip becomes heavy enough, and that changes rain to snow.
I don't expect much, if any accumulation in the Boston area, maybe a slushy coating around Rte. 128 on grassy surfaces as rain and snow battle it out for a few hours in the early evening. The snow will lose that battle to rain, although that process takes longer outside 495. It's not out of the question that some of the highest elevations in the Worcester Hills, Manadnocks pick up 2-4" of wet snow, most accumulation on trees, grassy surfaces and car tops. Perhaps even an inch or so of snow near and outside 495, into the city of Worcester, on grassy surfaces, but not as much on the pavement (ground temps are warm). It all depends on the track of the storm. If it's a bit more west, these totals are lower, but higher back through the Berkshires.
Rain totals along the coast are 1-2" with the highest totals across the Cape and Islands. Also winds peak tomorrow evening at 40-50mph with a gust or two near 60 across the Cape. Tides are astronomically low, but minor coastal flooding/beach erosion is possible.