Zone 7/8 Update: Winter weather likely Tuesday PM into Wednesday

A low pressure system moving into the Eastern Great Lakes will bring precipitation into the Northeast US from late Tuesday night into Wednesday morning. As this occurs, warming in the atmospheres mid levels will surge through the Mid Atlantic and New England, changing most areas over to rain. However, cold air in the lower levels (closer to our heads) will hang on fora prolonged period of time in parts of Eastern New York and interior Connecticut and Massachusetts.

This creates concern for the potential of snow, sleet, and freezing rain, as the low pressure redevelops to the south off the shores of Southern New England. Forecast models have trended cooler over the past 12 to 24 hours with the temperature profiles throughout these areas, especially over the mountains of Connecticut and Massachusetts, where the potential exists for notable icing.

Precipitation is likely to begin moving into the area from southwest to northeast on Tuesday afternoon, beginning as light drizzle as the atmosphere moistens and the system approaches. The best lift for precipitation won’t arrive until the mid to late afternoon hours, and will continue sporadically through the overnight period and through Wednesday morning. Forecast models show a notable decrease in temperatures in the higher elevations of CT/MA/NY during this time frame.

Forecast models suggest temperatures in the upper 20's and lower 30's in interior NY, MA and CT during moderate precipitation on Tuesday night.

Forecast models suggest temperatures in the upper 20’s and lower 30’s in interior NY, MA and CT during moderate precipitation on Tuesday night.

With light to moderate precipitation continuing through the overnight period, and temperatures near or below freezing in the higher elevations of CT/MA/NY, the potential exists for accumulations of sleet and freezing rain as well. The threat for accumulating snow remains uncertain, but sleet and freezing rain are the favored precipitation types given the warm layers in the atmosphere. Still — the event will be impactful with roads and surfaces becoming slippery and travel hazardous during the overnight period.

Light wintry precipitation may linger through Wednesday morning as a low pressure area develops off the coast of Southern New England, with residual moisture throughout the area. But generally, things will taper off as the morning arrives on Wednesday. Temperatures won’t warm much above freezing, but even the slight warmup on Wednesday should help to melt at least some of the accumulated wintry precipitation from the night before.

The overall threat areas for the event have been highlighted in our analysis map below. The main focus continues to be on the higher elevations of Connecticut and Massachusetts, where an impactful winter weather event is possible. But impacts from the event may also continue southward into parts of Central Connecticut and Massachusetts as well, especially during the early part of the event on Tuesday evening.

Impact map for January 17th - 18th, 2017. Icing is expected across the far interior of NY and CT.

Impact map for January 17th – 18th, 2017. Icing is expected across the far interior of NY and CT.