BOSTON (CBS) – And away we go. It has been 221 days since we last uttered that magical 4 letter word…that word that stirs up so much emotion. For some, it is reason for celebration, while for others, it just brings feelings of pain and depression. SNOW is back in the forecast.
Before you lose your cookies and head for the bread aisle…this is NOT a major winter storm heading our way…think of it more as a “winter appetizer” a little something to wet your appetite for the much larger meal to come.
What? Too early you say? Not really. 52% of Novembers (in Boston’s recorded history) have had measurable snow. Granted we haven’t had much snowfall in recent Novembers…the last measurable snowfall being 2.6” back on November 27-28, 2014 in Boston. But point is, it does happen.
Snow in November is tricky…to get a decent accumulation near the Coastline, you need just the right setup in the atmosphere. Ocean temperatures just to our east are running right around 50 degrees, so any significant wind off the water and you are cooked. The farther inland you go however, things aren’t so difficult. The mountains of central and northern New England have already had several episodes of snow accumulation. In southern New England this time of year, a little bit of elevation can be key. The Berkshires, Monadnock Region and Worcester Hills often see snow much earlier than those in the Coastal Plain. So, armed with that knowledge, let’s tackle our first snow blog of the season!
First and foremost, this is being written more than 48 hours before the projected start of the event. 48 hours is typically our magic window, once we get within that timeframe confidence typically rises exponentially. Point is, there will certainly be some tweaking to this forecast over the next 12-24 hours, although we don’t anticipate any large forecast swings.
So what can we say definitively right now?
Well, first off, the storm IS coming. There is not a hit or miss scenario.
The storm will almost certainly START as snow. Temperatures over the next few days will be plenty cold enough (at the ground and above) to support precipitation falling as snow.
The majority of the snow will fall BETWEEN commutes…likely just after the Thursday PM commute and by Friday mornings commute the snow will be long gone (at that point it is rain and ice falling).
This will NOT be a major snowfall accumulation. The upper range in Southern New England should be about 4”-5” (and that is well away from the Coast).
There are no coastal flood issues, tides are very low astronomically. There will be some gusty winds at the Coast, but the winds will be a secondary concern to the snowfall accumulation.
First flakes arrive along the South Coast around 7pm Thursday night. Boston starts snowing between 8-9pm and all of Southern New England is in the snow shield by 9-10pm Thursday.
The majority of the snow accumulation will occur between 7pm and about Midnight…only a 3-5 hour window. After Midnight, the warm air invasion begins. At high levels of the atmosphere, a layer of warm air floods in all the way in Southern New Hampshire. At the same time, stronger east-northeast winds (off the Ocean) bring milder air in along the Coastal Plain. So, a very snowy looking radar just before midnight will quickly transition to pinks (sleet) and greens (rain).
By Friday morning’s commute, surface temperatures should have warmed enough for all rain to be falling anywhere inside of I-495. Outside of I-495 (points north and west including parts of Middlesex county and Worcester county) travel will be hazardous with sleet and freezing rain falling.
The rain/ice tapers off in the afternoon on Friday. By the PM commute the storm is just about done. Any untreated surfaces may freeze up in the I495/Rt128 areas as temperatures drop back to around freezing.
HOW MUCH SNOW:
2”-4” The highest amounts of snow will fall where you might expect they would in mid-November…well inland and in somewhat elevated locations including the Monadnock Region and Worcester Hills. Expect snow totals to range from around 2” in the I-495 area (Marlboro to Haverhill) to close to 4” in those elevated areas farther to the north and west. Any 5” totals would likely be solely in the Berkshires and up in Central and Northern New Hampshire.
1”-2” Inside I-495 and away from the immediate Coastline, expect a small accumulation, which will largely be washed away after temperatures rise and subsequently change the snow to rain.
Coating – 1” Right along the immediate Coastline (including Boston) and down towards the Cape and Islands, there will be a light accumulation in the first few hours of the event and then it will all be quickly washed away.
The main concern with this storm is the snow and ice and its effects on the roads. The winds may gust to 40mph or slightly higher along the Coast and over the Cape and Islands during the storm, nothing too strong…only minor wind damage possible.
And, with tides being astronomically low, there are no coastal flooding concerns.
This is just the beginning! A mere appetizer for the winter to come. Curious about how cold or snowy the winter of 2018-2019 might be? Tune into WBZ at 11p on Thursday night for our official winter forecast!
Follow Terry on Twitter @TerryWBZ