J.Spin

Event totals: 0.5” Snow/Trace L.E. The cold front had clearly passed and the snow shut off last night after an additional 0.2”, but we just got another round of snow this morning after observations time. When I get a chance I’ll try to figure out if it goes with this event or gets rolled into its own. Details from the 6:00 A.M. Waterbury observations: New Snow: 0.2 inches New Liquid: Trace Temperature: 23.0 F Sky: Mostly Cloudy Snow at the stake: Trace

Event totals: 0.3” Snow/Trace L.E. Details from the 6:00 P.M. Waterbury observations: New Snow: 0.3 inches New Liquid: Trace Temperature: 32.2 F Sky: Light Snow (2 to 5 mm flakes) Snow at the stake: Trace

I haven’t seen any notably snowfall down at our elevation yet today, but it must have started up fairly recently because there’s light snow out there right now. It looks like the BTV NWS AFD has it covered well, and it definitely emphasizes the importance of orographics with respect getting some lift: Area Forecast Discussion National Weather Service Burlington VT 332 PM EST Mon Dec 14 2020 .SYNOPSIS... Snow showers will be possible through the overnight hours across the higher terrain of the Adirondacks and northern Green Mountains with minor snow accumulations possible at higher elevations. .NEAR TERM /THROUGH TUESDAY NIGHT/... As of 330 PM EST Monday...We are beginning to see snow showers begin to blossom across the eastern coastline of Lake Ontario this afternoon ahead of an approaching polar cold front. Looking at the latest observations and satellite data, the cold front is currently situated across western Lake Ontario and will continue to push quickly eastward through the remainder of the afternoon hours into the overnight hours. Looking at some of the forecast soundings across northern New York, it still looks like the lack of lift through the snow growth layer is going to be a severe limiting factor for snow shower activity across our forecast area. The 12Z GFS/CMC/NAM model guidance shows virtually NIL frontogenesis (surface convergence) along the frontal boundary which is why the overall forcing remains sub-par. This should lead to much of the shower activity this evening and overnight to likely be orographically driven with any accumulations likely tied to the higher elevations of the Adirondacks and northern Green Mountains. Accumulations up to an inch or so will be possible across the higher terrain with little to nothing at lower elevations.

It looks like that stretch was about six days with snowfall, and it certainly had that classic feel of the typical regime we’ll get into here with constant flakes and pulses of higher intensity snowfall buried within the flow. It does feel a bit strange to not have flakes after that, but it looks like the potential is back starting today into tomorrow. The NNE mountains, and especially the Northern Greens with their relative positioning and connection to the Great Lakes, are definitely notable for the number of days you’re going to have snow in the air. There are certainly climates that get more snow, like parts of the Rockies, the Sierra, and similar high mountain places, but a lot of those climates are drier and their snow typically comes more in batches. They can go for long periods without any precipitation. To get into that 100+ days of snow a season type of climate, I think you have to look at places like coastal BC, Hokkaido, parts of Honshu, etc. There are probably various microclimate spots out there in the world that we just don’t know about, and likely some U.S./Great Lakes places do it was well, but the best combination is going to be a combination of mountains for consistent lift and a body of water for a supply of moisture. Checking my CoCoRaHS records, it looks like we’re at ~22 days with snow thus far on the season at our site.

I haven’t been in the main thread for a while, so I’ll have to check out the discussion. I do 6-hour clears when I can, and 12 or 24-hour clears fairly often as well depending on work, travel, etc. This fall I’ve been working from home a lot, so I’ve actually been able to do more 6-hour clears than usual. That disparity in clearing intervals seems to have been around a while, and it always seems to go back and forth; I asked my local CoCoRaHS representative a few years back, and he said it was fine the way I was doing mine with 6 to 24-hour clears. It’s really hard to get snapshots of snow density throughout a storm if you’re always waiting until 24 hours to clear. I guess if one wanted to do that, they could go with multiple boards, and you can leave one collecting and settling for the full 24 hours, and have others that you clear at intervals to get intermediate measurements on snow density. That’s just more work and gets confusing though vs. just clearing your board/boards and resetting everything for the next interval. As far as I know, the NWS does 6-hour clears, so if a CoCoRaHS observer doesn’t do that, then the observations aren’t as comparable between those sites. I think CoCoRaHS is perhaps pushing the 24-hour thing to simplify it for their observers; not everyone has the time or discipline to deal with 6-hour observations, running liquid analyses every six hours, etc., so if they want everything to be somewhat standard among their observers, it comes across sort of shooting for the least common denominator or something along those lines. A few other points about the 6 vs. 12 vs. 24-hour clearing intervals: 1. To some degree it’s a “who really cares” sort of thing. If someone clears more frequently and ends up with a few inches of extra accumulation, or even an extra 10% accumulation vs. clearing at the minimum frequency, what happens? Nothing. Nobody really cares. The police aren’t coming around to fine CoCoRaHS for not getting their volunteers in line, and it’s not as if any of us are attempting to calibrate snowfall for some high-level NIST standardization that’s going to affect everyone’s livelihood. It’s just a bunch of volunteers engaging in doing their best to measure a highly variable/inconsistent phenomenon. 2. Any variance in snowfall due to collection interval issue has basically got to be small potatoes compared to the inaccuracies people deal with in windy locations. 3. As long as you’re accurately collecting liquid, the snowfall thing is in many respects, moot. Liquid trumps all, and doesn’t vary with any sort of collection interval. For CoCoRaHS observers who aren’t collecting liquid with their winter snowfall measurements, they should be. That’s what CoCoRaHS really cares about much more than any snowfall numbers.

Thanks for bringing it to our attention. I was wondering why I hadn’t seen it when I flipped through the ECMWF Precipitation Type/Rate plot on pivotalweather.com, but I realize why. It just looks like the northern extent of whatever was passing by to the south of us, and I didn’t think it would even represent anything in terms of accumulation (I don’t find the shading scheme they use there for precipitation very helpful, so it’s hard to know if it means anything unless it’s darker, or you dive into it to check on actual amounts of precipitation). As noted in the conversation here, this seems like just an ECMWF thing vs. something all the models have, so we’ll have to see if anything comes of it. From the bulk of the guidance I’m seeing, the back side of the next system sort of looks like classic westerly flow with moisture from the lakes helping out the northern 1/2 to 1/3 of VT and NH with some snow. It doesn’t look like a robust signal, so maybe just a few inches in the mountains. The BTV NWS mentions it in their AFD: Area Forecast Discussion...DELAYED National Weather Service Burlington VT 717 PM EST Fri Dec 11 2020 .LONG TERM /MONDAY THROUGH FRIDAY/... As of 347 PM EST Friday...Fairly quiet weather will prevail through the first part of next week. A upper shortwave will rotate by just to our north Monday, pushing a front through with a second shot of colder air. This front combined with a bit of lake enhanced moisture will allow rain/snow showers to develop Monday afternoon into the evening, mainly across the northern mountains.

I didn’t get a chance to put them together until today, but I’ve got a few images from yesterday’s tour up at Bolton:

I went for a tour at Bolton today, so I can pass along the elevation profile for snow depths I saw, and some observations. Here are the snow depths I observed: 340’: 2” 1,000’: 3-4” 1,500’: 4-5” 2,000’: 7” 2,500’: 8-9” 2,700’: 9-10” 2,700’ was as high as my travels took me today, so I can’t provide observations above that level, but snow depths probably would have increased a bit more with elevation. The resort is reporting 4-8” of new snow in the past 24 hours, and 10” in the last 48 hours, and that recent snow is probably making up a lot of what I saw. There’s decent substance to the snow (i.e. it’s not just fluff), but really not too much base below that snow from what I saw. I just don’t think there was any dense snow, or rain-affected snow that had a chance to consolidate below these most recent accumulations. The snow quality is good though; the snowpack I encountered was right-side up with some medium weight density snow below fluffier powder on top. I’m surprised to see a depth of only 8” at the Mt. Mansfield Stake at 3,700’, but I’m not sure when that depth was last updated. Based on the amount of liquid equivalent that seemed to be in the snow, and the sub-freezing temperatures up there, this would likely be the start of the winter snowpack unless we get a really warm/wet, long-duration event. Consolidating the snow that’s there right now and/or adding some water to it would certainly help form a base. I’m not sure if the snow we have in the valleys around here is quite enough to mark the start the season’s snowpack, but it’s possible.

Event totals: 3.3” Snow/0.24” L.E. Details from the 12:00 P.M. Waterbury observations: New Snow: 0.2 inches New Liquid: 0.03 inches Snow/Water Ratio: 6.7 Snow Density: 15.0% H2O Temperature: 36.0 F Sky: Cloudy Snow at the stake: 3.0 inches

Event totals: 3.1” Snow/0.21” L.E. Details from the 6:00 A.M. Waterbury observations: New Snow: 1.0 inches New Liquid: 0.10 inches Snow/Water Ratio: 10.0 Snow Density: 10.0% H2O Temperature: 33.3 F Sky: Flurries Snow at the stake: 3.5 inches

We’ve been in a bit of a lull for the past few hours with just light snow/flurries, but it looks like there’s another pulse of moisture moving in from the northwest that could reinvigorate the snowfall:

It's been great having Phin, and all the new blood in the NNE thread – it’s been quite active. We need to get more people up here, because as you said in your other post, the mountains are the place if you like active/interesting weather. And if you like winter weather, the mountains of NNE are arguably the best place to be in the country east of the Rockies.

Event totals: 2.1” Snow/0.11” L.E. The snow density came down significantly with the addition of those larger flakes to the stack, and we’ve been back and forth with both larger and smaller flakes throughout the afternoon and into the evening. Details from the 6:00 P.M. Waterbury observations: New Snow: 1.3 inches New Liquid: 0.06 inches Snow/Water Ratio: 21.7 Snow Density: 4.6% H2O Temperature: 30.2 F Sky: Light Snow (1 to 4 mm flakes) Snow at the stake: 2.5 inches

Ha! Nice shots, and nicely put. I guess that calls for another Northern Greens symbolic image to add to the collection…

That sounds great. We’ve generally had rather small, synoptic-style flakes until about an hour or so ago, when we started getting larger, ½” – 1” flakes. That allowed the rate of accumulation to pick up a bit, so we’re at around 2” now. This next round of accumulation will likely come in below the roughly 12:1 snow density from this morning, since the stack it should have a mix of flake sizes in there.

LOL Phin, I’m pretty sure I’ve heard you say you go hiking with the kids! Sure, boot-packing up a steep slope with your skis over your shoulder through two feet of powder would definitely end up being more work that a typical hike, but most of the time that’s not how we’re doing it. When ascending with skins, a round trip up the mountain and down is actually less effort than an equivalent hike on a typical hiking trail. With a pre-made skin track or a groomed slope, proper skinning technique, and an appropriate ascent angle, climbing snow on skis is actually easier than hiking. You’re not carrying your skis; when you’re skinning, you just lift your foot slightly take the pressure off your ski to allow it to slide, then repeat to take the next step. On a typical packed surface, ascending on snow via skins is easier than hiking because the surface is flat and consistent, and you don’t need to expend extra energy negotiating trail obstacles, picking foot placement, etc., etc. And then the down… LOL. As long as you’re a competent skier, it’s literally an order of magnitude less effort/easier than hiking down. In terms of energy usage, skiing down a mountain is like putting your car in neutral and cruising with gravity. In contrast, hiking down a mountain is the equivalent of applying your car’s brakes, and then revving the engine way up to overcome the application of the brakes so that you can move at a regular speed. It’s hugely counterproductive, and a massive waste of all the potential energy that you just earned by ascending. And, the above comparison doesn’t even take into account the powder aspect. Most often, we go ski touring so that we can ski untouched powder on the descent. So instead of just skiing down, you’re descending the mountain as if you were floating on a cloud. A descent that was already incredibly easy, is now made ridiculously easy and hugely enjoyable. Oh, and as if that wasn’t already enough, there’s the additional aspect of often having the entire trail to yourself. Now there is one caveat to this – powder skiing is only easier than groomed skiing if you’re a competent powder skier. If you’re not proficient at skiing powder, then it can actually be more work than skiing groomed terrain. There’s an easy fix for that though… just learn to ski powder. If you’re already a good powder skier then you know what I mean, and if not, well you literally live in the mountains of NNE, so you can ski a lot of powder if you want and get really good at skiing it. My wife and I hiked Mansfield with the boys this fall, and it was a roughly 3,000’ vertical hike. For whatever reason, the downhill was especially brutal that day. I still hike, but ski touring has kind of ruined plain hiking for me somewhat because the touring is just so much more enjoyable and requires much less effort. So while it may seem exhausting, it’s actually not if done efficiently, and of course the result is days like this:

Event totals: 0.8” Snow/0.05” L.E. The current snow from this system is a notable change from what we’ve been seeing over the past few days – the flakes here are relatively small, with a definite synoptic feel. The density of the noontime core came in at 8.0% H2O, which is higher than anything I’ve recorded in a couple of weeks. This snow is definitely adding more substance to the snowpack though. Details from the 12:00 P.M. Waterbury observations: New Snow: 0.5 inches New Liquid: 0.04 inches Snow/Water Ratio: 12.5 Snow Density: 8.0% H2O Temperature: 31.5 F Sky: Light Snow (2 to 3 mm flakes) Snow at the stake: 1.5 inches

We’ve got steady light snow here, so if the usual trends you talk about hold up, you should have snow falling again before too long.

Event totals: 0.3” Snow/0.01” L.E. We got a brief break in the snowfall last night, so Mother Nature has made it relatively easy to find the demarcation between the end the last event and the start of this one. The point forecast here suggests something in the 3-6” range for snowfall with this system. Details from the 6:00 A.M. Waterbury observations: New Snow: 0.3 inches New Liquid: 0.01 inches Snow/Water Ratio: 90.0 Snow Density: 3.3% H2O Temperature: 30.0 F Sky: Light Snow (2 to 4 mm flakes) Snow at the stake: 1.0 inches

Yeah, there are definitely people out there with this perception, but from what I’ve seen we’re talking very casual skiers here – folks that would be at a level where if you asked them what the typical annual snowfall was for a ski resort, they’d have no idea. Similarly, they also have to be folks that don’t follow weather very closely, and the times they do pay attention to it a bit would be when a big coastal snowstorm is making headlines. So if it’s a storm that is positioned correctly such that it’s making headlines because it’s affecting the big coastal cities, the NNE resorts are typically getting fringed, and it’s going to be resorts in SVT and similar areas that are getting walloped. So I assume this is where this population of casual skiers/casual weather observers gets that impression – they watch the news/weather during these big storms, and see the big totals highlighted at SVT resorts. That’s all they know, and they assume this is the normal snowfall routine; they have no idea that big storms like that are maybe a once or twice a season thing. They’re not following snow reports at other times of the season, so they’re oblivious to what’s typically going on, and they’re also not the type to go looking into ski resort websites to look up annual snowfall numbers. PF interacts with visitors a lot at Stowe, so I wonder if he’s ever experienced this phenomenon. The thing is, his visitors are already up at Stowe, so they may already be far more aware of the differences from down south vs. folks who only ever visit the Southern Vermont Ski Areas.

I totally agree, and with the numbers that keep staring me in the face, that’s got to be the case. Combine 150”+ of reasonably dense synoptic snowfall with the excellent retention of a place like Sunday River, and things will generally work out fine. You’re even going to have some nice powder skiing on the days with fresh snow, you’re just not going to get, on average, the supply of powder that you’re going to get in places like the Northern Greens with an additional 150”+ of champagne on top of that. I think Sugarloaf falls right in line with that theory as well. In that 1995 Powder Magazine article, their annual snowfall average was reported as 164”, although I’ve now also seen numbers out there like 189”, and it looks like they’ve got a “very round” 200” on their website. They’ve probably got bit more elevation, perhaps a bit of help from their great latitude, and then they might get in on a bit of upslope, to boost them over Sunday River. With the incredible snow retention at Sugarloaf, things work out quite well with the annual snowfall they get.

I see that the BTV NWS is getting a bit more detailed on the upcoming system; the Mansfield point forecast suggests something in the 6-10” range. Area Forecast Discussion National Weather Service Burlington VT 634 PM EST Tue Dec 8 2020 .SYNOPSIS... Light snow returns though early Wednesday as an upper level disturbance passes over the region and continues Wednesday night before becoming confined to the mountains on Thursday. Snowfall will range from a dusting to an inch in the lowest elevations, with 2 to 4 inches across the western upslope regions, and over 6 inches on the higher peaks.

I hear that on the dust – I didn’t even get 0.01” of liquid out of the 0.4” on the board at the 6:00 P.M. clearing. I did get a total of 0.38 mL of liquid from two stacked cores, but that comes in at 0.0021” of liquid per core, which is still well under the 0.005” threshold where it would round up to the 0.01” level.

Event totals: 3.8” Snow/0.07” L.E. Well, maybe this is the last round of observations for this event. We’ve still got some flurries out there, but accumulation since the last clearing is sub-0.1” at this point. Whatever goes on with the tail end of this storm, the next system is virtually on our doorstep anyway. Any clearing that we might have had today is supposed to give way to cloudiness tonight, and I see snow chances in the point forecast starting up tomorrow morning. The current point forecast here suggests something in the 4-7” range for this next event. Details from the 6:00 P.M. Waterbury observations: New Snow: 0.4 inches New Liquid: Trace Temperature: 23.2 F Sky: Flurries Snow at the stake: 1.0 inches

I’m right there with you; I’m shocked every time I look at the reported snowfall averages up and down the spine, especially with so many people having the perception that the Southern Vermont Ski Areas get the most snowfall in the state. Does the annual snowfall really fall off nearly 100” over the southern half of the state? I guess it’s not inconceivable, since it appears to fall off roughly that much over the northern half of the state, but it would seem like there would need to be a “floor” for annual snowfall numbers at some point. I almost feel like I’ve previously seen (I’m not sure how many years ago) Killington/Pico with snowfall averages around 225”, which kind of fits nicely in the annual snowfall gradient from north to south. But, that’s clearly my memory trying to smooth things out, because I just checked back in the SkiVT-L archives from 1997, and even then, Killington is listed as having an annual snowfall of 250”, and that was referencing the big Powder Magazine ski area snowfall article from 1995: https://list.uvm.edu/cgi-bin/wa?A2=ind9703&L=SKIVT-L&P=359221 A few things to note on the 250” number though: 1) Remember that Killington does have roughly 700’ of vertical over Mount Snow in terms of summit elevation, so if both resorts are reporting summit area snowfall numbers, that’s a pretty substantial disparity. That’s more vertical than some of the SNE ski areas that people were recently talking about in one of the threads. 2) You know when you’re seeing super-round numbers for averages , such as “250 inches”, they are very likely heavily rounding whatever the average is. So they could easily have average snowfall of something like 235” and be rounding to the nearest 50”. 3) Continuity – see below The fact that the Killington annual snowfall average was listed as 250” 25 years ago is worthy of consideration here. I’m pretty sure they have been owned by various companies during that time, and there has to have been substantial turnover in management, snow reporters, and other positions. Is there really some systematic conspiracy in place to have everyone consistently over-report snowfall numbers so that they can get to approximately 250” every season? It’s really hard to imagine that over all that time, there’s not one person who’s going to stand up and refuse to fudge numbers? Or somehow, despite what must have been plenty of managerial and mountain ops turnover, some sort of sacred edict to inflate snowfall numbers to 250” has been handed from manager to manager, observer to observer, etc.? And here’s a related argument that seems even harder to punch holes in. Mount Snow reports that mid-150” snowfall average, and I’m pretty sure they’ve been reporting that number for a similar time to Killington’s 250” number. The same argument goes for how in the world are they going to get by low-balling their snowfall numbers for all those years? As an example to reinforce that, one that always blows my mind as well, is the annual snowfall average for Sunday River. They report an annual snowfall average similar to Mount Snow (I’m seeing current numbers out there ranging from 155” to 167”). Think about that, Sunday River has plenty of latitude – they’re at essentially the same latitude as Stowe. How in the world does a place like that get such little snowfall? Are they low-balling their snowfall numbers as well? What resort in their right mind though is going to constantly low ball their snowfall numbers? Even if “snowmaking” is your thing, and you’re not really concerned about natural snowfall, what’s the point in doing that? The conclusion I keep coming to, year after year as I think about this, is that those 150”-ish numbers are the real annual snowfall numbers for places like that. Think about it, Sunday River has plenty of latitude, and they’re positioned ridiculously well for getting hit by typical “coastal” storms. How do they only get 150-ish inches of snow a season? I think part of it is what I was saying in that big “coastal” storms (or even with the Atlantic as a primary moisture source as you nicely put it) just don’t contribute a ton of extra snowfall on a seasonal basis. I think it really comes down to that theory that PF has – there’s sort of this “floor” of synoptic snow around the Northeastern U.S., that doesn’t change a ton with respect to an area’s geographic position. There are of course the usual elevation effects on that, but that’s pretty much canceled out comparing mountain sites that are all in the 3,000’ to 4,000’ range. I think if mountains don’t get in on some sort of “extra” moisture/snow, such as upslope, lake-effect, or whatever, then those low numbers are what you’re going to see. The increases above that base annual snowfall are what really set them apart, and that increases dramatically as you head north up the spine of the Greens.