December 19th, 2024

 

Daily forecast discussion…

Christmas is getting closer, so the travel forecast is important!

The surface chart shows our 1^st cold front is off the coast with another trying to approach the Coast.  Behind the first cold front we’re seeing a change to sun, with breezy winds and cooling temperatures.  The 2^nd cold front over Northern New England down through Pennsylvania is in the process of stalling out. There are a few hit and miss snow showers over northern parts of the region, with a bit of lake effect falling downwind of Lake Ontario.

Another Clipper currently over the Upper Midwest will be dropping South and East. Tomorrow this will be weakening over Southwest Pennsylvania, West Virginia and Virginia. From here we will see energy transfer off the Coast, where a secondary area of low pressure will develop, For later Tomorrow into Saturday.  Gusty winds will bring in frigid Arctic Air, as these winds move over Lake Erie and Lake Ontario, they will allow for lake effect snow to fall downwind of Both Big Lakes. This is going to be the coldest air so far this season for the weekend into the first part of next week.

As the storm develops off the Coast it will be moving North and East heading toward Nova Scotia. This track will keep the bulk of the storm out over the ocean. But as cold air filters in, rain will change over to some snow over interior parts of the Northeast. There are signs that the storm dynamics could allow for measurable snow into southeast Massachusetts, down into New Jersey. An accumulation of a few inches upwards of a foot of snow will be possible over parts of Pennsylvania, New York State, and Northern into Central New England. Where the boundary layer between the cold air pushing in the warm air to the east will be very important. Those along the boundary, in Down East Maine, Eastern Massachusetts, Rhode Island and Southeast and Southern Connecticut, Long Island including New York City, back into New Jersey and Southeast Pennsylvania could see the first snow of the season, with accumulations of a trace to a couple of inches. There could be locally higher amounts as well, along that boundary. Who sees what will depend on the exact track the ocean storm takes.

As the ocean storm approaches Atlantic Canada, strong high pressure will push down from Canada, this will bring even colder air for Sunday and Monday. Skies will clear and winds will subside, leading to a very cold Sunday night into Monday morning. The high pressure will also shut down the lake effect snow bands.

Tuesday a warm front will be lifting in, this could allow for snow showers, for Christmas Eve for a large part of the region. Light snow accumulations are possible. Christmas Day, looks to see lingering snow showers. But these shouldn’t cause travel issues. Thursday, another coastal storm looks to develop, this will be another complex setup, with rain, mix, and snow for the region.