Lake Champlain delivered an inch or two of surprise snow to the high country surrounding the MRV Tuesday. All it takes this time of year is the right wind direction (northwest) and just a minimal amount of low level instability and the magic happens. We expect some additional snowfall on both Wednesday and Thursday. It won't be much but its something and it comes thanks to a weak jet stream impulse riding along a temperature boundary. A corridor of moisture should establish itself from the Adirondacks to the Green Mountains by late morning Wednesday and although the best moisture and snowfall appears confined to the Adirondacks, light snow is likely to bring another small accumulation to the MRV by evening (1-2 inches). This snow is likely to continue and become flurries and snow showers Thursday though temperatures are likely to climb to above freezing levels in low lying areas even as another 1-2 inches is received across the high country. Not a bad 3-day stretch but a rather mild day Friday is likely to eliminate decent percentage of our midweek fluff, whatever falls.
Beyond Friday the forecast has become more challenging but in the aggregate has improved just a small amount. A tight jet stream in the Pacific will have an adverse impact on the weather pattern, providing an invariable headwind that is likely going to continue through the winter solstice.The pattern is not "unblocked" at high latitudes however; in fact, a rather significant block is expected to form over the northeast Russia and migrate over the Chukchi Sea just northwest of Alaska. This combined with a broad area of ridging in Scandinavia and Greenland is expected to flood northern North America with arctic air. Yes, much of it will be centered in northwest Canada but some will migrate eastward as well and cross the mostly frozen Hudson Bay (it has become mostly frozen early this year). It's all so La Nina but it also means arctic cold will become a more capable ally during any weather situation beginning this weekend. It still looks rather mild late Friday into early Saturday but the approaching storm no longer appears to be a spent force in the Midwest and will approach with a bit more cold air to work with. We still might see a bit of ice and rain but base building snow in northern New England is now within our grasp. Were it to happen, it would happen late Saturday into early Sunday. Models are all over the play and I expect they converge on a solution in the next day or two.
Precipitation late Saturday or early Sunday could be the start of a few days featuring unsettled weather. Models are hinting at multiple waves of activity with a second wave of precipitation possible around Monday. One area of cold air will be retreating northeastward into Canada at this time while a new area of cold will be arriving behind this second wave. The details are just impossible to sort out right now and are so likely to change that any attempt to pin this forecast down is pointless right now. That said, the period between Saturday to early Monday does appear a bit colder in northern New England and capable of potentially supporting some snowfall yet still incapable of allowing for a big event or eliminating all the rain/ice from the outlook.
Next week's weather isn't likely to end with Monday either. A La Nina pattern in a La Nina winter appears set to send wave after wave in our direction with another one producing another possible storm during the middle or end of next week. This storm has the best chance of being an all snow-producer across interior New England but such an outcome is hardly a guarantee. Models are having enough problems with the next 5 days making the weather beyond a week especially blurry.
The longer range ensembles continue to paint a similar picture as we approach the Christmas holiday. The jet stream in the Pacific appears angry while cold air is positioned close by in Canada thanks to a negative AO/NAO combo. It will be active and we need to place ourselves on the right side of the action or it will be more rain and ice. Two things that will help moving forward are this. 1) Moving deeper into the heart of the cold season moves the expected storm track southward simply because of climatology. 2) 44 N latitude is a good spot. We won't miss too many storms the rest of this month because we are too far north. Instead, we are likely to see several events where latitude is helpful.
1 comment:
Bring on the snow!
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