BOSTON (CBS) – Stock up on snowblowers and dust off the shovels, winter is about to come.
So far we have had very little impact from the cold and snow. Sure, we’ve had a few cold days and even a slight build-up of snow here and there, but the true New England-style winter is yet to come.
Let’s be clear, there aren’t any big snowstorms in the forecast yet, but a definitive shift to a more “typical” December weather pattern is underway.
Before we get there we do one last 60 degree descent and maybe a record Thursday. From coast to coast, the weather is very volatile at the moment. A powerful storm is making its way through the middle of the country and will bring severe weather to areas where there is currently a solid snowpack (southern Minnesota), several inches of snow on the west side (Dakotas and northern Minnesota) and a abundant wind. and record heat across much of the central and possibly eastern United States
Temperatures here in New England will bottom in the mid-1960s on Thursday (the record in Boston is currently 64 degrees) and barely drop Thursday night. We’ll start in the 50s on Friday morning and stay there until later in the afternoon when the colder air finally begins to come in.
That brings us to this weekend. It’s not one of those situations that will hit or miss, a storm is coming. The difficulty lies in marginal temperatures and who gets rain versus who gets snow. Marginal temperatures are not only at ground level, but also at altitude.
Many models indicate a warm layer (above freezing point) several hundred feet above the ground. And while that might sound pretty harmless, essentially the entire column of atmospheric air is cold enough for snow except for that tiny layer with temperatures just above 32 degrees, that’s really all you need to know. need to spoil a good snow forecast.
Precipitation comes out of the clouds as snow, falls thousands of feet as snow, but then flows into a layer of air warm enough to melt the snow into rain … probably refreezing as sleet or rain freezing (once you lose the snow you can’t go back).
The forecast will boil down to that layer of air, somewhere between 4,000 and 8,000 feet above our heads. If it’s over 32 degrees, you can pretty much say goodbye to any significant snowfall. If it stays just below freezing, we have a widespread light to moderate snowfall buildup, and you will be shoveling or plowing Sunday morning.
Worst case scenario snowfall appears to be around 1 to 3 inches just outside Boston (north and west), roughly an inch just off the coast, and 3 to 6 inches north and west of 495 (north of Mass Pike and certainly north of Hwy 2). Once again, this is if, and only if, the hot “nose” of the air does not intervene.
If the warm layer did materialize we would probably get very little snow, perhaps some scattered coverings a few inches from the start (north and west) quickly passing to rain and sleet throughout the southern part of the country. New England.
Chronology of the storm:
First flakes and drops: late Saturday morning / noon
Culminate: late Saturday afternoon until around midnight (worst trip)
Last flakes and drops: around dawn Sunday
Obviously there are a few things that need to be sorted out, usually within 48 hours of a storm, those little details tend to be best worked out. We’ll keep you posted on any changes before and during the event on WBZ-TV, CBSBoston.com and CBSN Boston.
Currently, next week is shaping up to be cold and calm with the general track of the storm moving well towards southern New England. So this MAY be our last chance for a White Christmas.