Final Call for Fast-Moving Tuesday Mess
Light to Moderate Amounts Expected
Synoptic Overview:
It now appears as though piece of energy pinwheeling around the PV lobe over southern Canada will amplify slightly more than originally anticipated in Saturday's First Call.
This amplification to the west of the area will trigger a southwest flow aloft, which will advect warmer air in to clash with the antecedent cold in place to proddice a period of precipitation.
The fact that the system now looks to amplify slightly more than originally anticipated will have two primary impacts on the forecast:
1) Total amounts of precipitation will be slightly higher given greater warm air advection, which is the primary cause of precipitation in this instance.
2) Precipitation type issues will be more of a factor than implied with the issuance of the First Call.
Here is how the storm is now expected to play out.
Anticipated Storm Evolution:
Light snowfall should break out along the south coast later this evening and towards the Mass Pike:
And to the New Hampshire/Vermont borders by midnight, as snow becomes steadier and somewhat heavier to the south.
Snowfall should mix with and chance to rain over the islands by the Tuesday AM commute after up to an inch of snow, however, the vast majority of the region will experience a rather slow commute, so allow plenty of extra time tomorrow morning.
After 1-3" of wet snow, precipitation should have transitioned to rainfall across the rest of the cape by the end of the commute and will be mixing with sleet and rain along with south coast of New England.
The snow should rapidly begin mixing with sleet up through and north of the Boston area by midday, during the heaviest burst of precipitation.
And into southern New Hampshire before tapering off Tuesday afternoon.
While freezing rain should not be a major issue in this system, a small area across northern and central Connecticut may experience some noteworthy glazing. through midday Tuesday.
Final Call:
First Call: Saturday January 13th @9PM: