It started snowing right on cue late yesterday afternoon so it seemed that the forecast was on its way to verification. NOT! The weak impulse passed through during the evening and created the dusting to an inch across most of the region except over southeastern MA and especially Cape Cod where 2-5″ accumulated. The projected snowfall close to the coast was highly dependent upon the development of a snow band associated with the “Norlun Trough”. The band blossomed overnight but its alignment and placement shifted east just offshore thus sparing the North Shore, South Shore and the outer portion of Cape Cod. Frankly, I am not a bit surprised because, as I pointed out yesterday, this type of specialized trough is very tricky to predict and in my nearly 40 years of forecasting, I can state with accuracy that it is about as forecastable as the Northern Lights! Conditions have to be perfect and I have seen only a handful of cases where the Norlun Trough was prolific releasing a narrow sliver of intense snowfall much like what happens in the skinny strings of lake-effect snow squalls downwind of the Great Lakes. This morning’s radar is revealing that some intense snowfall is occurring over portions of the Gulf of ME thanks in part to the great instability created by the warmer than usual ocean and some very cold air streaming in aloft. As last evening progressed, it became apparent that the snow band was setting up father offshore and Todd Gutner reduced the snow threat along the coast. So we press onward to address the next weather makers.
There will be a changeable sky of bright sunshine yielding to spells of passing patches of clouds which may yield scattered flurries or snow showers in places mainly this afternoon. The northwesterly wind will freshen to 12-28 mph as temperatures max out near 20 in Worcester County to near 25 in Boston and closer to 30 over southeastern MA and Cape Cod. Colder and colder air will be advancing into the region with time leading to lows tonight in the in the upper single numbers in Boston down to near or somewhat below zero farther and farther north and west of the city with 10-15 degrees on Cape Cod. A Wind Chill Advisory has been issued for Worcester County westward from 10pm to 10am as it will feel like 10 to 20 below zero out there at times! There will be a moonlit sky tonight followed by lots of sunshine yielding to patchy clouds tomorrow. I think that maximums tomorrow will be in the upper single numbers in the Worcester Hills to near 10 north and west of the city to about 13 closer to Boston to 15-20 south of the city to Cape Cod and the South Shore. The wind will be biting at 12-22 mph and will even be stronger at 15-35 mph on Thursday with similar or just slightly higher temperatures in bright sunshine. Overnight lows both Wednesday night and Thursday night will be in the single numbers above to single numbers below zero. Across ME, NH and VT, it will be as much as 10-25 below zero especially in the colder northern areas.
Looking ahead, we’ll be monitoring the progress of a parcel of energy exiting the northern Rockies Thursday on its way east and southeastward to collect some moisture from the Gulf of Mexico. It appears that this upper level disturbance will become more defined and stronger with time leading to the development of a storm in the Midwest. This system has the potential to intensify upon reaching the Mid-Atlantic Coast on Friday. From that location, it should track northeastward to deliver us a classic snowstorm. It has far more potential than last night’s trough because it should be a widespread event of several inches to a foot or so of snow. There could be some rain involved on parts of the Cape. It is really to premature to be confident of specifics but right now it appears that the storm will max out Saturday morning with the heaviest snow and strong winds. With 4 days to go before its arrival, there will likely be some zigging and zagging as usual so this solution/prediction cannot be etched in stone just yet. In any event, after its passage, northwesterly gales would blow on Sunday amidst bright sunshine. Milder air will be here next week with temperatures recovering to the 30s on Monday and perhaps rising to 40-45 on Tuesday.
Todd Gutner will provide a fresh blog early this evening.
Make it a great day!