Saturday, January 28, 2023

Pattern to finally allow for a short-lived blast of bitterly cold temperatures this Friday into Saturday

A decent area of snow is expected to cover much of southern Quebec and some of this will impact extreme northern Vermont such as Jay Peak on Sunday. Farther south and over the MRV, this event will be mostly a dud with the best frontogenetics remaining to our north. It will turn out warmer than some earlier projections as a lot of northern Vermont will remain on the wrong side of the current clashing temperature regime. It's still cold enough to snow across the high country on Sunday and a sloppy inch or two remains a likely outcome, but the valley floor could actually see some light rainfall out of all this as the day progresses and temperatures are likely to range from the low 30's high up on the mountain to 40 on the valley floor.

Arctic air is expected to seep into northern New England on Monday putting us back on the right side of the temperature clash for the rest of the upcoming week. Additionally, precipitation will become snow and fall sporadically Sunday night into Monday and a period of steadier snow later Monday appears capable of depositing a few inches of snow, mostly for the Tuesday ski day. There are additional waves of energy in this fast flowing jet stream late next week but models have moved to shift the action southward leaving much of Vermont with a drier outlook even though smaller impulses in the now present polar jet stream appear capable of bringing snow showers back to the high country at least once. It will be worth watching how models handle the weather system late Wednesday into Thursday and whether that could blossom into something significant. As of Saturday evening however, data has been moving in the opposite direction and snow late on Monday January 30th may turn out to be the most we see during the upcoming week. 

The outlook does appear colder in the big picture and a big reason for this stems from the evolving outlook Friday into Saturday, February 3rd and 4th. Looks like New England is finally going to get a frontal assault of arctic air, unmodified by the Great Lakes as was the case with the cold outbreak around Christmas. The jet stream impulse responsible for delivering the cold could also deliver a little snowfall. There is no doubt we will be creating some incredible thermals off Lake Champlain once this bitterly cold airmass hits the unfrozen body of water, but in spite of favorable flow, these airmasses tend to be extremely stable in nature and thus greatly reducing the convective snowfall opportunities. The cold will be incoming on Friday and be accompanied by dangerous windchills for a time, especially at the summit areas. I would not be surprised to see actual temps drop to -20 Saturday morning in a few spots though there remains a little uncertainty as to how much of the core of this cold can focus on Vermont or whether the most intense area can get deflected. We should see wind chill temperatures abate on Saturday, but much of the day might be spent below zero on the mountain. Temperatures are expected to quickly modify for Sunday into Monday and by that time, we are looking at our next chance for a potential weather system the the jet stream is expected to remain quite strong and appears to be limiting the opportunity for storms to strengthen along the east coast. 

Beyond Monday, arctic air is expected to retreat some and the pattern is expected to realign focusing storminess and the cold out over the Rocky Mountains. Unlike this past Christmas however, arctic air is expected to remain present over much of eastern Canada and not vanish from the North American continent as it did before the New Year. The pattern does appear to favor another outbreak of mild weather, especially below 40 N latitude and there appears to be a risk of an inland runner around the time of February 8th or 9th, but northern New England will have the ability to avoid a disastrous thaw given the presence of a colder regime in Canada. Ironically, the +NAO which is not helpful for east coast storminess and snowfall can help make a potentially dangerous jet stream flatter and hopefully Vermont colder. Needless to say temperatures have been mild across New England and all of the east coast this January and I feel confident saying that February will turn out substantially colder than February in northern New England. I would not say that confidently further south, below the 40 N aforementioned latitude.

1 comment:

Southern NE skier said...

Relative to normal, February/March is likely to be cooler than January in both northern and southern New England/NYC, but that isn't saying much.

Central Park is completing its warmest January since 1932. Its coldest temperature was 28. The odds favor some type of reversion to the mean. If so, that should be favorable for the rest of the season in ski country.

We're not going to experience a replay of March 2012. Are we?