J.Spin

We picked up 0.06” from the initial frontal passage, and then another 0.12” from the secondary cold frontal passage. We didn’t get any frozen with that second push, but the precipitation just changed over to snow and we’re getting accumulation, so snow levels have now dropped to the valley floors in this area now.

We’ve had 0.05” of L.E. thus far here at our site in the valley. While a tenth or two of L.E. means essentially nothing in the context of snowmaking terrain, for those of us looking to get out on natural snow, this is much more significant. Putting that L.E. down as a dense accumulation (vs. only liquid) just further enhances the base snow that’s out there right now, bolsters it for more resistance from temperatures above freezing, and preps it to be that much better of a base when the powder comes. So while L.E. values like those don’t matter much for snowmaking trails, or even steep natural terrain, they can be very helpful for the low-angle grassy stuff that supports those early powder turns. We’ll have to see what that potential Friday system does, but the current temperatures in the ~2,000’ elevation range are the warmest they’re forecast to be for the next week, so whatever comes from this system really could hang around to help out the natural base.

I think farther to the east, the temperatures must be going up before they come back down later in the storm cycle. If you look at the point forecasts in your area, it shows temperatures rising tonight through tomorrow morning into the upper 30s F before they start to come back down around noontime tomorrow.

I just checked the Sugarbush snowboard webcams, and it’s snowing at their 3,900’ cam, as well as at their 3,125 cam, so the snow level is somewhere below that as you surmised. I’m surprised that snow levels aren’t expected to rise in the near term with the southerly flow, but apparently not? It looks like temperatures stay steady and then come down as the storm cycle continues. I’m seeing L.E. in the 0.1” to 0.2” range mentioned for this storm, so nothing too prodigious, but a nice little addition for the upper mountain areas if the snow line only falls from here.

Yeah, that system is looking colder than this one, and has more upslope potential as well, at least as it’s currently depicted in the models. I don’t know about a strongly defined low that’s right near us, but it looks like the potential money maker could be low pressure assuming a position somewhere from Northern Maine on up into the Maritimes. Variations of that are shown on multiple models, and that’s what would bring that more potent period of upslope snow. That timeframe is only 4 to 5 days out, so definitely something to watch at this point. And watching at this range is even more appropriate than it is in many other storm setups, because a low doesn’t even need to be placed perfectly up there. Sure, some low positions are going to produce better upslope than others, but you get into that general cyclonic flow with some moisture, and the mountains can do their thing. I’ve found that’s certainly one of the big differences in the snow climate up here vs. places like SNE. Getting defined surface lows placed perfectly/appropriately/nearby is great, but it’s a huge crap shoot, and sometimes it seems like areas to the south can spend half the winter waiting for a pattern to set up that will place lows exactly where they need to be to produce decent snow. That’s unnecessarily burning part of the season that could be producing snow (at least in terms of average temperatures), which is probably one of the factors that produces the lower snowfall averages and higher variance in areas to the south.

I’m thinking the snow line starts out in the 3,500’ – 4,000’ range? PF may have looked at the details and have more accurate thoughts. The BTV NWS doesn’t always say too much when the snow levels are high, since travel impacts are low to nonexistent. I’m seeing 3-6” as a point forecast in the Presidentials at ~5,500’, so certainly some help in loading the ravines to bolster the snowpack there. Indeed that snow line is really up there near the resort summits, so not helping out too much there as you said, and I totally agree, let’s hope it gets down into at least the mid elevations of the resorts. As is typically the case, the lower that snow line goes, the better. The BTV NWS has generally light amounts overall, although they do have the snow levels getting down as low as 1,500’ over here, so that’s dropping all the way to the base elevations. Area Forecast Discussion National Weather Service Burlington VT 255 PM EST Sun Nov 21 2021 NEAR TERM /THROUGH MONDAY NIGHT/... As of 139 PM EST Sunday...Total snowfall expected 1-2" across the Green Mtn summits tonight and Monday, and locally 2-3" at summit level in the Adirondacks. At more modest elevations of 1500-2500`, have indicated just a coating to 0.5" snowfall across nrn NY and far nern VT.

Yeah, there’s not really much shown on the back side of that – it may just be one of these that the snow levels drop from the peaks as it progresses, sort of like we’ve seen. It’s not really a rain system though – the 540 line is forecast to be in NNE at the start of the system and it quickly moves southward, and 850 temps are below zero the whole time. Temperatures at elevation in the Presidentials are never even forecast to get out of the 20s F.

It’s not something that really shows up on the global models, but there’s a bit of a potential bonus event that is appearing on some of the mesoscale models for tonight into tomorrow morning. It seems pretty minor, but enough to be mentioned in the BTV NWS AFD below. The first system I mentioned in the quoted text above delivered yesterday’s snows, and the other two seem to still be on track in the modeling. There’s also another event starting to show up at the tail end of the month now, but it’s a bit far out there to say much and might just be leftovers from the preceding system vs. an actual disturbance of its own. You can pretty much see the periods with these systems on the ensembles as well. The pattern does seem to be as advertised, and these aren’t huge events that require special phasing to happen – they’re just moving through in the flow, so there’s a degree of reliability there. These systems certainly aren’t all snow at all elevations, but they do seem like typical November fare. It’s not quite one of the plentiful bread and butter patterns that gives us something almost every other day, but it’s definitely active with systems to monitor that have snow potential. Area Forecast Discussion National Weather Service Burlington VT 1234 AM EST Sat Nov 20 2021 NEAR TERM /THROUGH SUNDAY/... As of 1222 AM EST Saturday... Heading into Saturday night, that upper ridge starts to shift east, and deep southwesterly return flow will develop once again. It seems that there could be some light activity as the ridge moves east during the pre-dawn hours of Sunday with guidance showing a bit more in the way of activity this last cycle. Forcing isn`t substantial, which should prevent much in the way of measurable amounts. Overnight lows in the mid 20s to mid 30s.

Event totals: 0.2” Snow/0.62” L.E. We picked up a bit more accumulation today, but the sky has been clearing and there’s not much on radar, so that may be the last of this system.

At observations time this morning I found some accumulation on the board – it was partially melted and not immediately obvious where it had come from, but the radar did show some bands that had moved through earlier. It was a few degrees above freezing at the point, so it may have been something like graupel or sleet that can survive temperatures above freezing for a while. It started snowing just as I was leaving the house, with much more standard, fluffy flakes – presumably thanks to the lakes and/or northwest flow. We’ve even had flakes falling here in Burlington today, with a couple of stronger squalls, and I see on our webcam that we’ve had some accumulation at the house as well.

Was it seriously just six days ago that you were so optimistic? It feels like it was weeks ago at this point. I hadn’t realized that people were visualizing a “cold” pattern for the rest of the month – to me it just looked like it was going to be active, with our typical November snow chances. I’d think for a consistently cold pattern, we’d need to see a persistent trough in the area, and I don’t recall the models ever showing that. We’ve definitely had the snows – multiple systems at this point, and the models suggest there are more to come. I’d say there are at least three more storms with possible snow in the models? – the back side of this current system, something near the beginning of next week, and then something near the end of next week. PF has pointed out how it’s not looking like a great period for snowmaking down to base elevations, so that’s obviously tough on the resorts if they’re planning to open top-to-bottom. I’m more interested in getting out for natural snow turns though, so every storm with snow is an opportunity for that. I’ve been a bit too busy the past couple of weeks to venture out for turns, and it felt like it was still just a bit thin down low, but I’m definitely watching each storm that comes through for the next possibility.

I’d argue from experience that parts of NNE/NNY are almost always in play from any system through the heart of winter – between the elevations of the mountains, the areas covered by LES, the latitude all the way up to Northern Maine, and prominent CAD sites, you really have to have extreme warmth to take that entire region out of the game. I guess it depends on what you definition of “in play” is, but mine is the possibility of at least some snow/frozen from the system, and it’s the rare system in midwinter where there isn’t the chance of at least something for this neck of the woods. Many of our events are not going to garner a lot of interest in the main thread though.

Yeah, I was going to message in about the stunning views around here today – enjoying the west side sights of the spine from my office right now. The sights aren’t nearly as brilliant now that the clouds have moved in, but it’s great to see that snow line way down there. I grabbed a quick shot of Mansfield with the cell phone:

Event totals: 1.8” Snow/0.87” L.E. I’ve got my observations below from when I got home yesterday evening, and I’d say that’s the end of that system, so the above totals should be the final numbers at our site. At elevation, where this system was mostly snow, this was a great shot to the snowpack. Unfortunately I’m not seeing any recent snowpack data at the Mt. Mansfield Stake to get a sense for where it stands at the moment to think about whether or not this could represent the start of the season snowpack. If there’s a foot or so of dense snow up there, this certainly could be the start of the snowpack. With this system having wound down now, it looks like the next systems with snow potential are the one coming through tomorrow into Friday, and then maybe something early next week. Details from the 8:00 P.M. Waterbury observations: New Snow: 0.2 inches New Liquid: 0.11 inches Snow/Water Ratio: 3.6 Snow Density: 27.5% H2O Temperature: 29.5 F Sky: Cloudy Snow at the stake: 1.0 inches

We were getting some decent snowfall out of that as the stronger echoes came through. Accumulation was still relatively slow due to the marginal temperatures and relatively small flake size, but you can see from the CoCoRaHS L.E. map how it’s added to the total liquid from this event in our area:

I guess this event isn’t quite done yet because it even started snowing here in Burlington – I see on the radar that it’s got the look of a big batch of streamers on WNW. It seems to be hitting the mountains now, so you might get an uptick in snowfall if the spine does its usual thing.

Event totals: 1.6” Snow/0.86” L.E. We’ve had a good shot of liquid with this system so far at our site. It wasn’t until later in the day yesterday that it really started to accumulate here, but if we’re at 0.86” of L.E. so far, the local peaks must be around an inch of L.E. by this point, with a lot of that as snow up high. There’s only a weak radar signature out there right now, but we’ve been getting some steady light snow this morning to add a bit more accumulation. Flakes have been small (1-2 mm though), so I don’t expect accumulations to amount to too much unless that changed. I’ve got my past couple of rounds of observations below, and some travel observations from yesterday. I was heading home a bit late from Burlington in the evening and the temperature was 37 F. At that point there was no precipitation in the Champlain Valley, and roads didn’t even start to get wet until I got into the mountains. I was surprised to not see any snow until I approached the town of Bolton, and then everything changed in what seemed like an instant. The road was covered with an inch or two of unplowed slush, and it definitely pushed you around while driving. At home the temperature was 33 F, and the slush on the road had almost disappeared relative to what I’d seen in Bolton and Bolton Flats. Here are the past couple round of observations from our site: Details from the 8:00 P.M. Waterbury observations: New Snow: 0.4 inches New Liquid: 0.11 inches Snow/Water Ratio: 3.6 Snow Density: 27.5% H2O Temperature: 33.6 F Sky: Light Snow (1-2 mm flakes) Snow at the stake: 0.5 inches Details from the 6:00 A.M. Waterbury observations: New Snow: 1.2 inches New Liquid: 0.22 inches Snow/Water Ratio: 5.5 Snow Density: 18.3% H2O Temperature: 32.5 F Sky: Light Snow (1-2 mm flakes) Snow at the stake: 1.0 inches

I saw on the Sugarbush Summit Snowboard Cam that they had 8-9” on their board as of this evening, but I don’t think they’d cleared it since the previous storm? It looks like one of the snowmakers cleared it about 20 minutes ago (you can go back in the video and see him doing it and that it was a bit of a stretch at times; the board is pretty elevated without much snowpack in place yet).

Look at the flow right now, it’s basically perpendicular right into the spine.

I’ve got an update from the Winooski Valley this morning – snow line was around 1,500’, so that’s where it seemed to settle in by the morning hours in that area. I saw a car that I assume came down from Bolton that seemed to have about an inch of snow on it, and their base area webcam at 2,100’ shows that they definitely got a refresher of the previous snow.

Updates on the running accumulation at your snow plot are great – what’s the elevation there again (I know it’s somewhere in the 3,000’ range)? It certainly looks like there will be chances for additions to the November total going forward.

We had 0.42” of liquid with this first system, but I’m seeing higher amounts the farther wester toward the western slopes you go. How much L.E. for the mountain thus far? I’m assuming one had to go up to roughly ridgeline elevation to have it all/nearly all fall as snow?

That looks like the next opportunity – with a lot more potential on the back side vs. this last one. If indeed this current pattern holds for a couple of weeks as I saw mentioned on TWC the other day, you can see how a number of similar events could roll through by the end of the month. Even if you just continue to get 4-6” here, 4-6” there, with a couple systems having a bit more punch, it could bring accumulations in the Northern Greens in the realm of bwt’s comment about that GFS snow map.

We had precipitation linger a little while after that main shield cut off, but it was indeed quite dry on the back side – there just wasn’t much of a hookup with additional moisture as that dry air moved in. Down here at our elevation I could see that we got into the snow, but there was never any accumulation that I could detect. For accumulations in the higher elevations around here I’m seeing ~4” on the Sugarbush 3,900’ webcam, ~2 on the Sugarbush 3,125’ webcam, and at the Bolton Valley 2,100’ webcam it looks like accumulations in the 1-2” range.