Moderating Temperatures and a Clip from a Storm on Tap for New England
- Tim Dennis
- Feb 19
- 4 min read
As temperatures begin a very gradual moderating trend, the parade of storms New England has seen over the past couple weeks will be reaching its end. A nor'easter will pass New England well offshore Thursday into Thursday night. This will be the sixth large-scale, organized storm nearby New England in the past two weeks. These storms have varied in size, intensity and impacts, but the "Blizzard of 2025" was avoided (for now anyway, we're certainly not closing the book on winter storms now, as we enter into late February).
The last storm in this parade is poised to be the strongest, with most guidance dropping the storm into the 975-985 millibar range, which would certainly have had the opportunity to be a blizzard for New England. At this point, this is all "should-a, could-a, would-a" as the storm will be passing New England well outside the benchmark, bringing not much more than a glancing blow to southeast Massachusetts.
There remain some questions as to exactly how far north and west the outermost shield of snow travels into New England. This mainly has to do with a northern stream trough to the west of New England. Energy associated with this northern stream disturbance could help tug the outermost bands of the main storm system a bit farther north than they otherwise would have been pulled.
The northern stream system could create just enough forcing on its own to produce some light and scattered snow showers across northern New England Thursday and Thursday night. Without a moisture and energy injection from the southern stream, this would amount to little accumulations confined to northern Vermont.
Below: CMC showing potential weather Thursday night:
For the southern stream storm system, an inverted trough could develop with the storm, which will be the main thing to watch. With an inverted trough expected to develop in the afternoon, the coastal plain could see a period of enhanced snowfall along with a longer lasting period of snowfall. An inverted trough occurs when pressure increases from south to north, which is typically the opposite of mid-level troughs. Normally, the lowest pressure and heights are located on the south side of the trough, not the north side. Inverted troughs can look more like ridges.
These troughs can create enhanced precipitation rates and extend precipitation on the northwest side of the system. This could help set up a period of ocean-enhanced snow showers for the Cape and the Islands, leading to some accumulations when there otherwise wouldn't be much of anything. This isn't a major development and won't create a more impactful storm as snow amounts will remain light all around, but it will be something to watch in the final snow totals.
When all is said and done, a general 1-3 inches of snow will likely have fallen across the South Shore, Cape and Islands. With the aforementioned ocean-enhancement, the lower and outer Cape, along with the Islands, could see more, possibly on the order of 3-5 inches should ocean-enhancement be persistent enough. A winter weather advisory has been issued for Nantucket.
This is mainly based on current probabilities as a range in the extent of snow remains high. NAM continues to be the most aggressive with snow showers while the trusty HRRR shows very little even for the Cape and Islands. Currently, WPC probabilities show a 40-50% chance of at least 4 inches of snow on Cape Cod and as high as 70% for Nantucket.
Below: Current probability of at least 4 inches of snow:
We realize this may seem like it's becoming a lot of hoopla for a low-impact event with snowfall trending toward minimal amounts (or nothing at all) for a majority of the region, but we like to really dive into all the facets of weather events around here.
After this storm, a break in more organized storms will be coming. After two stormy weekends, a much calmer one is on tap this time around. A moisture-starved disturbance may quickly cut through over the weekend, potentially bringing light snow showers, mainly across the north. For many, this disturbance may result in only a period of increased clouds. The next system to watch comes early next week as a clipper is poised to move through the region with snow and rain showers. For the first time in a few weeks, New England’s 7-day precipitation outlook is rather minimal.
Below: Current 7-day precipitation outlook:
As far as temperatures go, a shift in the pattern will bring a moderating trend through the rest of this week and into next week. After brief downstream blocking for New England, the NAO Index is poised to rise back to a positive phase. The PNA will also remain positive and the EPO will trend positive. Without going into great detail (we go into more detail about what these index values all mean in our monthly outlooks), all of this points toward a Pacific influence to spread across the United States.
When influence from the Pacific increases, it often means more mild air spreads across the country, especially within a fast, zonal flow. This will help temperatures bounce back from being persistently below average. With that said, a big thaw doesn't look to be coming as a general ridge-in-the-west-trough-in-the-east remains broadly in place across the mid-levels. All of this points toward truly mild weather remaining to the west and New England seeing more average temperatures. Still, it may feel like a significant warm-up after this week.
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