J.Spin

Oh, I meant that add that in my post. My list is made north to south with respect to latitude, so when you see deviations in the snowfall trend from north to south, they are typically because of areas that are well off the spine (such as Burke, which is far to the east) or have lower summit elevations, like Middlebury. At least that’s what I’ve seen with respect to the deviations; the general trend in annual snowfall from north to south if you stick to the spine at fairly similar elevations is amazingly consistent. The deviations from that trend because of longitude definitely show the importance of being on the spine with respect to getting optimal snowfall. Ascutney, which is no longer operating as a typical lift-served resort so it’s not on my list of major resorts, was another great example of that – it’s annual snowfall was notably less for its latitude because it was well east of the spine. It may have been in the NNE thread when we talked about it, but I also have a list of Vermont’s smaller ski areas on my Ski Areas Page, and that one is also done north to south with respect to latitude. You can see on that list that there’s really not obvious trend with respect to annual snowfall. Those areas are really scattered around from east to west, and elevations probably vary a lot as well, so that would also destroy any obvious latitudinal snowfall trends. Hard’ack (82″) Pete’s Tow (99″) Lyndon Outing Club (103″) Chapman Hill (79″) Cochran’s (88”) Cosmic Hill (104″) Northeast Slopes (91″) Pine Mountain (65″) Harrington Hill (87″) Twin Farms (82″) Suicide Six (80″) Ski Quechee (90″) Bear Creek (150″) Ascutney Outdoors (175″) Timber Ridge (145″) Bellows Falls (56″) Hermitage (150″) Living Memorial (56″)

I think the issue here, at least in part, lies with something I brought up in my post above. The more I think about, the more I wonder how much (i.e. what percentage of annual snowfall) big coastal storms actually play into the snowfall numbers for the Vermont ski areas. This is where it would be good to bring in some of the meteorologists who know seasonal averages for those types of storms. I’m wondering if the past decade’s run of (more frequent?) big coastal storms has warped our perspective on how often they really occur. It takes a lot of things to line up just right to get one of those big coastal systems, and even more to get one that significantly affects a certain area, so is the real average on those more than once or twice a season? Even if a spot gets two solid hits from coastal storms a season, and each one is a healthy two feet of snow, that’s still a pretty minor component of the annual snowfall, even for a place with an annual snowfall average like Mount Snow. Those big storms get the attention, so perhaps why they’re thought to have such an impact? It’s not as if heading southward along the spine of the Greens we find that the big snowfall numbers up north experience some sort of dip in the central areas, and then rise again as one gets into the southern area where potential coastal systems have greater effects; the numbers just continue to drop as one heads south. If the “coastal” storm track doesn’t really contribute much to the overall annual snowfall averages, there might not really be any sort of in between area.

You’re on this forum, so you obviously know a lot about the actual snowfall trends up and down the spine, but you bring up a great point about the snowfall from coastal storms. There are actually a lot of folks out there (we’re talking very casual skiers/snowstorm watchers) who have the impression that the resorts in the Southern Greens actually get the most annual snowfall of anywhere in the state. This is because, as you note, they can often do quite well with respect to accumulations from notable coastal storms. I assume that if these are storms affecting the big coastal cities, they garner the most attention, and people may pay attention and get wind of the associated ski resort accumulations. But the actual annual snowfall numbers up and down the ski areas of the Green Mountains (see below) tell the real story and point out how ironic that is. I can only assume that the effects of the prominent coastal storms are so infrequent that they are vastly outweighed by 1) the greater frequency/impacts of storms to the north, 2) the far greater upslope enhancement in the mountains to the north, and 3) the latitude effects with respect to occasions when the rain/snow line for storms is in these latitudes. It’s probably a fun discussion to try to figure out what percentages each of these factors play in the snowfall increases heading north, and of course there may be other factors as well. I’ve pasted below the list of north to south annual snowfall numbers I have on the Ski Areas Page at my website. I’ve kind of kept these where they were when I put the page together for the most part, so they’re not all perfectly representative of the most recent years, but the trend is incredibly obvious. I just checked Mount Snow’s most recent reported annual snowfall average to compare to what I had, and their website has an average annual snowfall of 156” vs the 158” I’ve got on my site, so that’s pretty darned consistent over whatever period it’s been since I updated the page. You can imagine how strange it must appear to people who think SVT gets the most snow to learn that Jay Peak has an annual snowfall average of well more than double what Mount Snow gets. It just speaks to the fact that there must be a lot of systems that are either not affecting that area, or delivering rain/mixed precipitation there. Even for someone who follows the winter weather in Vermont very closely (and makes an effort to post ski area snowfall totals up and down the spine of the Greens for every notable system), it’s still startling how much the snowfall drops off down there. But the numbers are the numbers, and there just must be a lot of lean snowfall times that far south. It's not like a ski area to downplay or “underreport” their snowfall (unless you have someone like PF being extra cautious to ensure no over-reporting), so you have to assume they’re counting all the snow there is to count. I will say that as I run through the snow reports for the Vermont ski areas after each storm, I notice that in general the Southern Vermont Ski Areas don’t seem to take their snowfall measurement as seriously as the resorts up north do. I don’t mean to say they’re inaccurate or anything, it’s just that they don’t care about it too much. When I go to their websites for putting together storm snowfall numbers, their snowfall reports are often much harder to find, or buried deeper in the website. I think it’s because relatively speaking, supplying reliable manmade snow is a much bigger part of their marketing strategy vs. capitalizing on natural snow. They definitely feature their snow reports more prominently after a notable storm (such as with a headline or headline link on their websites), but for every day reporting, the placement of their snow report within the website definitely comes across as “Whatever, here’s the snow report if you really want to check it out.” Jay Peak (355″) Burke (217″) Smuggler’s Notch (320″) Stowe (333″) Bolton Valley (312″) Mad River Glen (228″) Sugarbush (250″) Middlebury (200″) Pico (250″) Killington (250″) Okemo (200″) Bromley (145″) Magic Mountain (145″) Stratton (180″) Mount Snow (158″)

The Central Greens are most definitely a defined geographical/geological area, per Peakbagger.com: http://www.peakbagger.com/range.aspx?rid=16131 In terms of their defining geology/geography, I know they are marked on the north end by the Winooski Valley; I’m keenly aware of this because we live right near the dividing line between the Central/Northern Greens sub-ranges. We’re just a bit north of the Winooski River, so our house is at the very southern end of the Northern Greens, and the Central Greens are across the valley. I’ve heard the Winooski Valley is a very notable geological feature because it is the most prominent east/west cut through the wall of the Green Mountains. I heard something at one point about how that was very significant, perhaps from PF, but it could have been somewhere else that I picked that up. On the southern end, I’m not as familiar with the geological feature dividing the Central Greens from the Southern Greens, but it looks like the valley encompassing Vermont Route 103 is a major component of the demarcation. Killington Peak is definitely the highest peak in the sub-range, so it’s certainly important in that regard, although as you can see, it’s near the southern end:

For some visitors, that wintry appeal is probably important. For the hard core skiers, they’re likely not too concerned if the situation in town isn’t supremely aesthetic, as long as the snow on the slopes is in good shape. But when you have families come up to vacation with non-skiers who want to just enjoy other winter activities, such as doing things around town, browsing the shops, etc., I bet it keeps them coming back if they know they can come up and expect to get those bucolic, wintry VT scenes.

The “bread and butter” expression is in used around here in line with its “basic means of support; source of livelihood; sustenance” definition, and it developed to describe some of the typical/frequent Clipper-style weather systems we get up here in the Northern Greens, and it of course would apply to other parts of NNE with similar climate. The meaning of the expression has actually been a pretty good fit because indeed the storms don’t look flashy on the surface, but they’re frequent, typically quite reliable, and help sustain the quality of the conditions on the slopes. They often don’t look like much to folks who aren’t in the know, but they can routinely put down a half a foot of snow in the higher elevations, simply due to the mountain orographics doing their thing. In the analogy, big synoptic storms like nor’easters would be some sort of special meal I guess. The term can be used to describe the type of systems, as well as the pattern, but this doesn’t feel quite like a full blown bread and butter “pattern” at the moment, at least in the longer-term sense. That type of pattern is most obvious when we can see multiple Clippers/shortwaves queued up on the models upstream, and then they come through every couple of days – sort of when it’s just the northern branch of the jet stream affecting our area. When the southern branch of the jet gets involved, it seems like there’s a lot less reliability (there can be issues of phasing, warm temperatures, larger deviations in track, etc.). But getting continuous/nearly continuous snow for days on end like this is definitely what you can get when bread and butter storms come through like they do. They hit the mountains, drop front side snow, and then back side snow can hang around for quite a while. When the systems are coming in fast enough sequence, they just sort of blend together and it can be hard at times to know when one system ended and another began. As someone who organizes my snow data by specific systems, this can get to be a bit of an organizational challenge at times. Anyway, if it’s continuously snowing over by you guys like it is over here, enjoy! Alex has commented on the aesthetics of this type of snowfall a number of times, so one gets the impression that he likes that sort of climate. The way it’s been lightly (although at times more heavily in spots) snowing almost continuously for the past few days is where the “snow globe” expression comes from as well.

There’s really only one thing to say about the look of that event…

You just replace the sleigh with a 2021 Subaru, and off you go. Currier and Ives actually do a pretty nice job with some of that snow globe snowfall.

Event totals: 3.4” Snow/0.07” L.E. I was going to suggest that this might be the last round of snowfall observations for this event, since we’re getting more and more breaks of sun and the snow seems to be winding down, but as I write this we’re getting another resurgence. Checking on the local radar, there’s a batch of moisture hitting the spine from the NNW, so the beat goes on. Details from the 12:00 P.M. Waterbury observations: New Snow: 0.9 inches New Liquid: 0.01 inches Snow/Water Ratio: 90.0 Snow Density: 1.1% H2O Temperature: 28.0 F Sky: Flurries Snow at the stake: 1.0 inches

Event totals: 2.5” Snow/0.06” L.E. Based on the robust snowfall rate here around observations time, it was obvious that it hadn’t been snowing that hard all night, and the radar below suggests the snow is associated with a recent push of moisture building in from the north and that small band quickly building in from the east. Details from the 6:00 A.M. Waterbury observations: New Snow: 0.7 inches New Liquid: 0.01 inches Snow/Water Ratio: 70.0 Snow Density: 1.4% H2O Temperature: 23.4 F Sky: Snow/Light Snow (2 to 15 mm flakes) Snow at the stake: 1.0 inches

Event totals: 1.8” Snow/0.05” L.E. Details from the 12:00 A.M. Waterbury observations: New Snow: 0.6 inches New Liquid: 0.02 inches Snow/Water Ratio: 30.0 Snow Density: 3.3% H2O Temperature: 22.6 F Sky: Light Snow (1 to 3 mm flakes) Snow at the stake: 0.5 inches

Event totals: 1.2” Snow/0.03” L.E. Getting into that band for a bit earlier today certainly increased the rate of snow accumulation relative to what we’d seen being outside it. We’ve actually got another band hitting the area right now with some pretty vigorous snowfall. Details from the 6:00 P.M. Waterbury observations: New Snow: 0.5 inches New Liquid: 0.01 inches Snow/Water Ratio: 50.0 Snow Density: 2.0% H2O Temperature: 24.4 F Sky: Snow (5 to 15 mm flakes) Snow at the stake: 0.5 inches

I get these from the Weather Underground BTV radar site – it actually lets you choose from a variety of beam angles, as well as the composite of course: https://www.wunderground.com/radar/us/vt/burlington/cxx I learned from PF that the composite is nice in that it gives you a chance to catch upslope and various other effects that you might not due to mountain shadowing. As you can see, PF uses lots of the different beam angles depending on what he wants to look at. I usually just default to the composite because you know you’re getting the most intense signals from various angles and catching just about everything there is to catch if it’s out there.

Cool, that should be interesting. I also see that there’s been what appears to be a LES band coming off Lake Champlain with this more northerly wind, although the band seems to be fading now.

PF, note that you can see the beginnings of that Waterbury streamer even on your radar grab from this morning. I hadn’t thought much of it at the time, but it’s obvious now. My wife said that it was already snowing in Waterbury when she headed off to work before 7:00 A.M. this morning, and she was just at the Shaw’s in town a little while ago and noted that they got a pretty good shot of snow there. She actually sent me a text early this morning to remark at how hard it was snowing as she went through Stowe, but I was working upstairs and didn’t check my phone until some point in the afternoon. I told her I’d gotten plenty of timely updates from you on the weather forum though!

I’ve got a local update on these mountain streamers. As I was back at the house checking out the radar, I was looking at the streamer down here, and it actually looked like it was shifting to the west (presumably due to a shift in the wind to a more northerly direction). It looked like it was actually shifting enough to bring it near our site, and sure enough, I was looking out the window, and an immediate wall of big flakes came down. It’s funny, having experienced going in and out of the streamer that we’ve got down here during my travels this afternoon, it’s clear that these streamers have a very sharp cutoff like LES bands vs. the typically broader effects we see with upslope. Sometimes we’ll get some very sharp upslope bands, but these have definitely shown quite the cutoff. I’ve got a radar grab below that shows the Waterbury streamer shifting to the west, and it quickly put down a half inch of snow when it got here. The radar image also shows another pulse of moisture coming into the area from the north.

So I got a bit of a surprise this afternoon with respect to this phenomenon. I had to drive my younger son to Harwood to meet with his driving instructor for some practice, which brings me right through town here in Waterbury. We left the house with the small flakes we’ve been getting since yesterday, and just as we reach the fringe of town, it starts pouring big ½” – 1” flakes in probably the 0.5”-1”/hr. range. It was remarkable how quickly it turned on, and then as soon as I hit the southern end of town and started to climb toward Duxbury, it essentially shut off, or was at most just very light snow with the type of flakes we’ve had here at the house. I figured I’d gone through a brief squall or something, but sure enough, as I drove back home, it’s pouring big flakes in the same place – right in town. As soon as I left town heading toward our house, it was back to the light snow/small flakes, and that’s the way it stayed. It was as if the center of town had its own little localized storm going on. I had to check out the radar when I got home, and from what I can see, it’s another streamer, just like the one you’ve been reporting on in Stowe. Looking at the positioning, I wonder if this one is coming off Bolton Mountain the way the one up near you is coming off Mansfield:

Event totals: 0.7” Snow/0.02” L.E. In classic upslope style, the light snow has been ticking along through today as the models suggested. Flakes have been quite small here at our site though, so accumulations continue to be fairly low. Details from the 12:00 P.M. Waterbury observations: New Snow: 0.1 inches New Liquid: Trace Temperature: 25.7 F Sky: Light Snow (1-3 mm flakes) Snow at the stake: Trace

Event totals: 0.6” Snow/0.02” L.E. Details from the 6:00 A.M. Waterbury observations: New Snow: 0.1 inches New Liquid: Trace Temperature: 24.8 F Sky: Flurries Snow at the stake: Trace

That’s pretty neat PF, even for around here in the mountains that’s pretty extreme localization! Here at our site we’ve been getting similar light snow and flurries to what we experienced yesterday, with another tenth of an inch of accumulation overnight.

Event totals: 0.5” Snow/0.02” L.E. The snowfall gradually wound down this afternoon, so that might be it for this event, but I guess there are still potential lobes of mid-level moisture out there that might affect the area over the next 12 to 24 hours and indicated in the BTV NWS AFD: Area Forecast Discussion National Weather Service Burlington VT 621 PM EST Sun Dec 6 2020 .NEAR TERM /THROUGH MONDAY NIGHT/... As of 612 PM EST Sunday...Cyclonic nw upslope flow prevails associated with mid/upper lvl trof acrs the ne conus from departing coastal system. Weak pieces of energy and lobes of slightly better mid lvl moisture continue to rotate thru our cwa for the next 12 to 24 hours. This general pattern will continue to produce on and off light snow showers acrs the favorable upslope regions of the northern dacks and central/northern Greens overnight into Monday. Details from the 6:00 P.M. Waterbury observations: New Snow: 0.1 inches New Liquid: Trace Temperature: 27.9 F Sky: Cloudy Snow at the stake: Trace

I had done a quick look through the models to see what was coming in the next week, and it looks like there are 3 to 4 chances to talk about. There’s this current system that the models suggest would be providing snow for roughly the next 24 hours, and then there’s some mid to late week potential as jc noted. Some model runs have shown that as two pulses, but most seem to show it as one long period of snow. That would run over a couple days though, so it could be a reasonably snowy period, but we’ll have to see how that trends as we move forward. The final chances would be out toward next weekend with a potential synoptic system. As currently modeled, the snow to consider there would be front side and back side snow because we’d be in the warm sector for part of that system. That pace of systems right now seems pretty normal, but only the shortwave period around midweek is really typical bread and butter stuff. Today’s snow is from that northerly flow, although I do see on the radar that it’s beginning to acquire a bit more westerly component, and then the modeling for the next weekend timeframe has the bulk of the snow potential to the west of this area until the storm passes.

Event totals: 0.4” Snow/0.02” L.E. We’ve generally had light snowfall all morning, but the flakes have been quite small and thus accumulation has been relatively slow. Details from the 12:00 P.M. Waterbury observations: New Snow: 0.1 inches New Liquid: Trace Temperature: 28.4 F Sky: Light snow (1 to 2 mm flakes) Snow at the stake: Trace

Checking out the local radar, there’s an obvious moisture stream coming into the area from the north. That’s definitely not our typical bread and butter northwesterly flow around here, but it’s keeping the flakes going even down here in the valley, so it’s certainly supplying a level of moisture. This is presumably the type of snowfall activity that the models have been showing to hang around through as Winter Storm Eartha departs. The models that are catching it well suggest this sort of stuff hangs around for roughly another 24 hours.

That’s really interesting; I didn’t check any of the forecasts over there, but on the precipitation type/moisture outputs from the models, it just looked like a general big swath of blue up and down the state of New Hampshire. Your site did what it’s supposed to do though, just like we’ve been saying based on the data!