Mixed Bag

 The cold has settled in, and with a storm arriving this weekend we’re in for a mixed bag of weather.  Temps tonight will be down into the teens for the coldest spots again.  The cold is settling in for the storm that arrives tomorrow night, but how long will the cold be able to hold on?  That’s really the question that is making this a tricky forecast.

This isn’t a “snowstorm” for us, even though we will see some snow in most spots.  This is more of a “wintry-mix” storm with everything expected:  snow, sleet, freezing rain, rain and even wind (especially along the Cape and islands).

On the leading edge of this storm, we expect snow for almost all areas.  This burst of snow moves in fast and furiously, dropping 3-5″ NW of 495, and a coating to an inch in Boston.  With the cold already in place, we won’t have to wait for the snow to start accumulating… it will just start piling up right as it starts to come down.  Then, warmer air upstairs works in and it does so quickly.  When you have that mild layer of air aloft, the snowflake will melt, and this is where we get the real trouble with this storm; it’s a perfect set up for ice.  The cold at the surface will be slow to erode, and the sleet and freezing rain will hang around until the mild air mixes throughout the atmosphere.  

It looks like snow will start to fall, and accumulate, in the late afternoon/early evening hours tomorrow.  I expect a burst of snow that changes over to a wintry mix before midnight.  The sleet and freezing rain will stick around through the early hours of Sunday morning, but I do see that mild air chewing away at the cold in all locations by about 7-8am.  The potential for this mild air is incredible, with highs up to 60 degrees not out of the question for SE Mass, and Cape Cod.

Really it’s the early hours of Sunday morning that will be the most slick… then just wet and drizzly for the rest of the day.  Nevertheless, we should all use caution on Sunday morning… if we do get a good glaze of ice to accrete, it will take a while to melt off.

A Winter Weather Advisory is in effect for most of the state through Sunday morning, and a Wind Advisory will be in effect on Sunday for the Cape and islands.  Winds will be out of the SW 15-25 mph, with gusts to 50 possible (though it often happens that winds out of the south have a hard time actualizing).

This burst of mild air is a quick BURST.  We’re back to cold temps, and even bitterly frigid temps for next week.

See you tomorrow! – Bri