Updated snowfall forecast for 11/27/12...looks like more snow

Yet another touch and complex snowfall forecast for our region as latest computer model guidance has trended stronger with the developing wave of low pressure tomorrow which will be sliding just to the south of our region.  With computer forecast models now deepening and strengthening the system quicker and closer to the coast, this will allow for more in the way of moisture and stronger lift to at least work into a portion of the region.  Given this it does appear some of the snowfall totals from the previous forecast will have to be bumped up a bit.

The highest uncertainty with this forecast will be out across eastern MA.  Computer forecast models have have the combination of strongest lift and highest moisture over this area, however, signals of an inverted trough setting up across SE MA could actually allow for warmer marine air to contaminate the lowest 2000' of the atmosphere giving this area more in the way of rain or a mix of rain/snow, cutting down snowfall totals.  On the western side of this boundary is where the highest snowfall totals are going to occur as on the western side these locations will still be under the strongest lift/highest moisture and will also be cold enough to support all or mainly all snow.  The million dollar question (and is always the million dollar question) is where this boundary, known as the "coastal front" sets up.

Snowfall should begin breaking out in the early to mid morning hours and start off light in intensity.  In fact, for much of the storm's duration the intensity will only range from light to moderate, with the exception being some areas from SE CT into RI and interior SE MA where stronger lift aloft will allow for more periods of higher intensity snows (possibly in the range of 1'' to 1.5'' per hour).  Snow will be ongoing throughout much of the afternoon and overnight periods when the system will finally begin to wind down as it moves off to the north and east.  Some leftover flurries are still possible on Wednesday, especially across eastern southern New England.

Areas along the RI/SE MA coast will also experience a mix of rain/snow, especially during the afternoon hours when temperatures in the lowest 1000-1500' of the atmosphere are a touch on the warm side and especially when the precip rates are very light.  During bursts of heavier precipitation, any precip would be mainly snow.

Given the above this is what I would expect:

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