02/12/2017
What's in store!
WINTER STORM WARNING NOW POSTED FOR ALL OF SOUTHERN VT/NH, WMASS, CMASS, EASTERN NY AND NORTHERN CT FOR MODERATE TO HEAVY SNOW TOMORROW AFTERNOON INTO MONDAY MORNING...THIS STORM WILL FORM INTO THE BLIZZARD OF 2017 FOR ESSEX COUNTY, MA UP THROUGH SOUTHEASTERN NH, THE ENTIRE MAINE COAST, COASTAL NEW BRUNSWICK, NOVA SCOTIA, AND ST. JOHN'S, NEWFOUNDLAND. ONE FOR THE AGES BACK EAST...
Good evening everybody, tonight is the calm before the storm, as yet another major snowstorm will be impacting our region. The steadiest and/or heaviest snow will fall tomorrow by early afternoon through Sunday night and into Monday morning. Light snow will initially have a hard time overcoming some dry air early tomorrow morning, but we should see light snow move in by late morning, and noon at the latest the way it looks now.
Before I get into more details, I did want to mention that if anyone is traveling west from Boston late tonight or early tomorrow morning, freezing drizzle is forecast there, and some slippery roads could result. We can thank high pressure for this, as it will slide a bit west tonight keeping cold air draining down into EMass (and our region, too). Ultimately the high will position itself north of Maine which will provide cold-enough air to produce a major snowstorm for some and a blizzard for others across a huge swath of New England.
BLACK ICE AND SLIPPERY ROADS TONIGHT
A number of main roads appear to be in good shape, but with cold temperatures dipping down into the high teens to low 20s tonight, snow-covered side streets form Thursday's storm will be slippery. In addition, some black ice could form from any snow melt that occurred earlier today, as some areas did get above freezing.
STORM SETUP
Surface low pressure is currently out over Missouri and will track east into the Ohio Valley overnight and into Sunday morning. As this storm reaches towards New Jersey, it will begin to strengthen much more as it prepares its trek and track south of Long Island to near Cape Cod the pre-dawn hours of Monday morning. Before that happens, an upper trough will dig southeast out of the Dakotas and through the Great Lakes which will help the storm to develop and strengthen.
An enormous plume of water v***r currently bifurcates the country, extending all the way from the Pacific Ocean near the Baja Peninsula, through the middle of the country, and off the Mid Atlantic coastline. There is no shortage of moisture with this system!
The storm will carry this moisture into the region tomorrow afternoon, and light snow should turn to moderate to heavy snowfall as the afternoon wears on, which will begin to accumulate on the roads, making driving problematic and ill-advised, especially towards sunset. Moderate to heavy snow with snowfall rates at 1+" per hour are possible at times through tomorrow night and into early Monday morning. Thundersnow is possible as the storm cranks, but that will be likely to our east this time around.
MIXING POTENTIAL IN NORTHERN CT/HAMPDEN COUNTY AND DRY AIR ALOFT AND AT THE SURFACE
While there is a decent chance that our precip type remains all snow throughout all of western and central Mass, the potential exists for some warmer air to move north for a brief period of time and mix in some sleet or rain. This could tamp down amounts but that remains to be seen.
Another feature that could lower amounts in the area generally south of the MassPike would be the potential for drier air aloft to work in for a time. This could make its way into the DGZ (i.e. dendritic growth zone), which is a very cold layer of air aloft where the fluffiest, most stackable snowflakes form - dendrites. This potential dry air could cut down on snowflakes production for a time.
Also, drier could work in at the surface up into northern CT for a time tomorrow evening as well. However, these areas should fill back in overnight into the pre-dawn hours of Monday as the storm bombs out off of Cape Cod. In fact, this storm could drop pressures down to below the strength of the Blizzard of 2013, making it stronger than that storm was at its height!
In closing out this section, it's definitely a tricky call for snowfall amounts from the MassPike south due to both the mixing issue and the drier air issues. We will just have to see if these things come to pass tomorrow.
AMOUNTS
Given everything I've said above, I believe that northern CT into Hampden County should see 5-10" of snow based on the above caveats, with 8-15" elsewhere throughout the region (meaning Berkshire, Hampshire, Franklin and Worcester Counties in MA, eastern NY adjacent to the Berkshires (i.e. the Taconics), and southern VT and southwestern NH). If the drier air stays south of Hartford and colder air pushes south, you could extend that 8-15" range further down into northern CT.
I think the greatest chance for over a foot would be in the Berkshires and, in terms of the valley, north of Rt. 9 and especially north of Rt. 2 up into southern VT. The jackpot zone for this storm looks to be northern Worcester County up into Cheshire County, NH, especially the eastern portion from around Mt. Monadnock eastward towards Peterborough, NH. Up to 18" could fall in these areas, as they will be closer to the bombing low, and could get into some wraparound snow bands due to the potential for the storm to stall for a time.
The snow may be on the wetter side initially, but should turn more powdery as the storm pulls away to the east Sunday night into Monday morning. Snow showers should continue in scattered fashion during Monday afternoon as well, and quit during Monday evening.
WINDS/OUTAGES
As the storm wraps up tight east of Boston, northerly winds will gust over 40mph at times in our region, so with heavy snow accumulations and some wetter snow possible, isolated power outages are possible. The winds will be greatest late Sunday night into and through Monday morning.
Brief blizzard conditions will be possible very late Sunday night and in the pre-dawn hours of Monday morning as well, assuming heavy snow and wind gusts over 40mph combine, which is possible. However, this storm will not verify as an official blizzard here.
A BLIZZARD FOR THE AGES
This will become THE Blizzard of 2017 for Boston, and especially up into Essex County in northeast MA, southeastern NH, and all of the bottom third of Maine especially near the coast, and even in coastal New Brunswick, Nova Scotia and St. John's Newfoundland. As one of my greatest weather heroes, Matt Noyes of NECN and NBCBoston, said on Twitter earlier, this will be a blizzard for the ages for some of these areas where over 2 feet of snow could fall with wind gusts to 75 mph possible. A wicked, wicked storm for Monday going into Monday night in those areas.
Ok, that about does it, I'm ready for a nap, dinner, and Anthony Bourdain on Netflix, not necessarily in that order. I hope you have a good night, and I will try to answer as many questions as I can before retiring for the evening.
I will also, of course, post an update tomorrow morning as the storm prepares to get underway in our neck of the woods.
P.S. I am not going to answer any questions about Wed/Thurs potential, as it looks more likely that northern stream low pressure moves over us and provides a period of light snow on Wednesday. The low-chance potential still exists for a coastal snowstorm, but I've got to get us all through this one first.
Enjoy your evening...
