We've had some decent late-season snow events in recent years, but its been since 2018 that we've had a March weather pattern capable of producing this type of persistent action. March of 2023 just continues to have that look with one storm now imminent and in this update we will highlight another around the March 12th time frame with an even higher ceiling. We are coming dangerously close to having a decent snow year now in northern Vermont even as the cherry blossoms begin to emerge a month early in the Washington, DC area.
Severe weather across the southeast is the major bullet point of our approaching strong winter storm which is situated over the Ohio Valley Friday afternoon, but will be southeast of Cape Cod by Saturday evening. In a pattern featuring a downstream block, such as the one we have now over Greenland, this is a pretty brisk pace and is the only thing holding us back from a 2-foot plus event. With all that said, the track of this storm is simply outstanding not only for the MRV, but for much of the state. Areas near the Mass border will see some sleet for a few hours, but I think the entire spine of the Green Mountains is in line for at least 10 inches. For us, the snow begins as the hour approaches midnight Friday evening and the higher resolution data suggests that some of the heaviest snow falls between 5 and 8am with rates exceeding 2 inches an hour. Be aware of that if you are plan to make the drive to Mad River Glen, Sugarbush or anywhere else in Vermont at that time. Heavy snowfall rates always slow travel by limiting visibility and making it difficult for road crews to keep up with plowing, even on the interstates. It also means that total accumulations by first chair will be around a foot (10-14") when by that point, the snowfall intensity should diminish though remain continuous throughout the rest of the day and into the evening. Across much of Massachusetts, interior Connecticut, and upstate New York this is a tricky forecast with temperatures hovering around the freezing mark and changing precipitation types which appear to include a lot of sleet and even some rain. I don't expect the sleet to be a major issue for Vermont however and much of that will be confined to an area marked by a line from Albany eastward to Greenfield, MA. Mad River Glen should see its snow continue into Saturday evening as an inverted trough helps enhance/extend the light snowfall, mainly over the high country. 4-8 inches of additional snow can be expected after 9 am giving us a 14-22 inch storm total. I narrowed the range slightly from previous expectations but this is now very in line with the National Weather Service forecast of 7-15 inches across valley locations. Forecasts for Sunday show a lot of clouds and even some snow flurries but I do expect some sunshine to return, at least in some intervals, which will help boost temperatures up close to the freezing mark.
The quick moving, but heavy snowfall producing weekend event might be followed by more snow late on Monday or early Tuesday from another rapidly eastward moving system. Why are these storms moving so quickly in this blocked pattern? Fluid dynamics ! The weather pattern remains bracketed by the aforementioned downstream blocking, but also the remnants of the strong southeast U.S. ridging in the jet stream which remains amazingly persistent in this La Nina year. Storms are currently being forced through a tight window, just south of us and are moving through window at a rapid pace much as a river would flow when forced into a narrow space. The storm Monday night is unlikely to bring heavy snowfall and may bring little to any snowfall, but we remain in play for some prior to the Tuesday ski day. After that, some additional moisture seems capable of rotating southward out of Quebec spreading some light but additional snowfall to the Green Mountains late Tuesday into Wednesday. All of this is accompanied by temperatures that are mostly expected to remain sub-freezing across high elevations.
This beautiful looking weather pattern is highlighted mainly by a negative EPO or a severely weakened west to east moving jet stream in the Pacific. In the near term we are aided by downstream blocking over Greenland or a negative NAO, but the blocking is expected to shift to the Bering Sea toward the middle of the month and this will act as a more effective mechanism for transporting anomalously cold weather into much of the North American continent. Of more importance is what the ensembles are signaling at an increasing intensity around the weekend of March 11th and 12th. For the last several days there have been signs of a big jet stream amplification in eastern North America and for the last 2 days there are clearer indications of a major storm. This event appears more like a Miller A, an appropriate storm type on the near 30 year anniversary of the king of all Miller A's, March 13, 1993. These events have an incredible ceiling of potential but they aren't free of risk if the storm tracks inland.
To reiterate, the pattern looks outstanding through the middle of March and should make for a lot of fun ski days. Get out and enjoy, but be safe prudent with travel decisions.
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