J.Spin

I got a text alert this morning that we’ve been put under a Winter Storm Watch, so I guess it’s time to start checking out the BTV NWS maps. On the alerts map, it’s Winter Storm Watches up and down the state of VT, and they also extend westward into parts of NYS. On the Event Total Snowfall map, we’re in the 8-12” shading for the period through 7:00 A.M. Wednesday. The point forecast here calls for 4-10” through Tuesday, but Tuesday night isn’t into the accumulations range yet, so we’ll have to see what’s expected there as we move forward.

I saw in this morning’s BTV NWS AFD that they’ve seen some northward shift in the anticipated precipitation for that upcoming system (Winter Storm Orlena). As always, an important aspect for up here is noting projections for components of the system to move into the Gulf of Maine or the Canadian Maritimes, where they can keep the precipitation going, vs. quickly heading eastward. Area Forecast Discussion National Weather Service Burlington VT 937 AM EST Sat Jan 30 2021 .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... As of 349 AM EST Saturday...The focus for next week continues to be a coastal low that will impact at least portions of the Northeast. There appears to have been a fairly significant northward shift with the precipitation from previous model runs. Main 500mb low now drifts directly over the North Country by Tuesday night, and enhanced lift helps to invigorate low pressure moving into the Gulf of Maine, rather than allowing the more southern low off of the Delmarva to have a more easterly track. Model consensus, including the GFS, ECMWF, and CMC now have the warm frontal band of snow lift northward well into central and northern Vermont, accompanied with increasing moisture and good omega in the DGZ. Hence, have increased snow chances to likely for the Monday night-Tuesday timeframe, especially from the Champlain Valley eastward. The upper low exits to the east by Wednesday morning, while the surface low(s) move into the Canadian Maritimes. The steadier snow will therefore taper off overnight Tuesday, transitioning to mountain snow showers by Wednesday morning on the favored western slopes as we remain under north-northwest flow. Still a bit early to be talking snow amounts; this system is fairly unorganized with any one of several surface lows having the potential to remain the dominant feature. At this time, several inches of snow does look possible across much of eastern Vermont, but any slight change in upper dynamics and associated surface features could mean more or less snow. Stay tuned for later updates.

Event totals: 3.8” Snow/0.14” L.E. The arctic flakes keep rolling along with the moisture on the back end of this system that’s been well off shore. The models suggest this is likely the last day for these effects though. Details from the 6:00 A.M. Waterbury observations: New Snow: 0.1 inches New Liquid: Trace Temperature: 6.8 F Sky: Light Snow (1-2 mm flakes) Snow at the stake: 13.0 inches

Event totals: 3.7” Snow/0.14” L.E. The snow density was notably increased with this latest round of snow, consistent with the smaller flakes that we often see with this type of cold air. Details from the 6:00 A.M. Waterbury observations: New Snow: 0.6 inches New Liquid: 0.05 inches Snow/Water Ratio: 12.0 Snow Density: 8.3% H2O Temperature: 0.5 F Sky: Light Snow (1-2 mm flakes) Snow at the stake: 14.0 inches

We had snow here at the house most of the morning, and it was generally light, but at times it would pick up with a burst of intensity with larger flakes. Toward the afternoon, the snowfall became a bit more persistent, and we were having longer periods with the large flakes, so it started getting to the point where I was wondering how much the mountains were getting. As it was snowing more heavily here, I checked out the Bolton Valley Base Area Webcam and saw what looked like really heavy snowfall, so I decided to hit the mountain for a couple of runs. The radar showed that another push of moisture was right on the doorstep as well: The radar didn’t look that outrageous, but I got up to Timberline and the snowfall was very heavy, probably 1-2”/hr with visibility of a few hundred feet. It was hard to tell home much had fallen recently, but I was finding 4-6” in many areas on the trails since the previous grooming. In any event, it was definitely a mini powder day up there, with that 4-6” easy to find essentially anywhere that hadn’t been skied recently. Very steep or windblown areas on piste definitely need another synoptic storm or two before they’re in prime shape, but the snow has continued to build up this week in the off piste areas. In areas that haven’t been skied in the past week or two, you’re essentially looking at 30” of unconsolidated snow down to elevations as low as 2,500’ now. There is some dense snow in there form the front end of Winter Storm Malcolm, but since we haven’t had any major thaws, there’s no layer in the snowpack that is fully solidified. My depth checks just went right down through the 30” to what I suspect is the ground, or perhaps a base of a few inches of old snow depending on the location. You really need at least moderate pitch to ski these areas because you’re sinking too deep for shallow slopes. I was on midfats today, so fat skis would help, but pitch is still going to be necessary. I’ve added a couple shots of the snowfall from when I arrived at Timberline today:

Yeah, when your slow periods are like this, you know you’re in a decent winter climate. I was up at Bolton for a bit this afternoon in 1-2”/hr snows. As I mentioned earlier, the slowest periods in the winter are typically when we get pinned under that frigid arctic air for an extended period. Other than that, it’s hard to go a week in midwinter without at least a small event or two.

Yeah, and if you want the epitome of that Northern Greens climate, you really can’t beat being at Jay Peak with some elevation. You’re definitely getting a good dose of it!

Event totals: 3.1” Snow/0.09” L.E. 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: 15.1 F Sky: Light Snow (1-3 mm flakes) Snow at the stake: 13.5 inches

It’s cool to see that there are folks out there who like that type of snowfall regime, although I’d say it’s still quite a minority of the people I’ve seen on this weather forum. Most of the forum focuses on tracking big winter storms. That’s a huge part of the winter climatology for a lot of places outside the mountains or LES areas though. From the perspective of many skiers, a winter pattern with consistency is where it’s at. Yeah, larger storms are important for base building or getting in those bigger powder days, and they’re awesome when they come around, but it’s the daily snows that will really keep the snow quality up. To get by with generally good to great ski conditions in a feast or famine snowfall climate, there really needs to be great snow preservation, such as is found in the high elevation/dry air climates of some of the higher mountain ranges.

Yeah, we’re into the back side moisture that some of the models like the GFS have been showing for this system (Winter Storm Nathaniel) to potentially persist through Friday/Saturday. It was hard to know how it would play out because only some of the models were showing it, but it looks like it’s there on most global and mesoscale models now. Thus far it’s been fairly light here, with a tenth or two of new snowfall per six-hour block, but we did just get some steadier flakes that dropped another half inch fairly quickly. It’s certainly been keeping us with that classing NNE mountain regime of flakes in the air. As PF would say…

Event totals: 2.0” Snow/0.08” L.E. The snowfall has recently picked up this evening, and it may be associated with the echoes that have popped up on the radar, but the look is very localized over the Champlain Valley at the moment. Details from the 10:00 P.M. Waterbury observations: New Snow: 0.1 inches New Liquid: Trace Temperature: 24.6 F Sky: Light Snow (2-10 mm flakes) Snow at the stake: 14.0 inches

Event totals: 1.8” Snow/0.08” L.E. We’ve still got a bit of light snow falling on and off today, but there’s not much on the radar that suggests any substantial accumulations for this event in the immediate future. Details from the 12:00 P.M. Waterbury observations: New Snow: 0.1 inches New Liquid: Trace Temperature: 32.4 F Sky: Light Snow (1-2 mm flakes) Snow at the stake: 14.0 inches

Event totals: 1.7” Snow/0.08” L.E. Details from the 6:00 A.M. Waterbury observations: New Snow: 0.5 inches New Liquid: 0.03 inches Snow/Water Ratio: 16.7 Snow Density: 6.0% H2O Temperature: 24.4 F Sky: Light Snow (2-5 mm flakes) Snow at the stake: 14.0 inches

Event totals: 1.2” Snow/0.05” L.E. Details from the 10:00 P.M. Waterbury observations: New Snow: 1.2 inches New Liquid: 0.05 inches Snow/Water Ratio: 24.0 Snow Density: 4.2% H2O Temperature: 25.5 F Sky: Light Snow (2-3 mm flakes) Snow at the stake: 14.0 inches

I’m not sure what time it started, but as of ~6:30 P.M. it was snowing pretty vigorously with some 1 to 2 cm flakes and ~3/4” of accumulation on the boards. It seems like fairly dry snow at this point, but I’ll have some info if I run an analysis later this evening.

Just eyeballing from the plot, it looks like SDD are in the ~50% range for Mansfield? Last week represented a good boost for the snowpack here at our site though – SDD were ~52% of average before that stretch, and now it’s up to 70% of average as of today. We’ve been doing much better on the season with respect to snowfall, but last week was still a solid contribution – it was a fairly symmetrical flip, bringing season snowfall from 8.2” behind average to 8.0” ahead of average.

I just cored the pack for CoCoRaHS today (I think they encourage folks to do it on Mondays anyway) and got 2.51” of liquid. It was actually a good time for a check on the water in the snowpack because there wasn’t any new snow yesterday, which was the first time since Christmas that I haven’t recorded at least a trace here.

The modeling definitely seems to be showing a northward trend with respect to that system, so it looks like we have the potential to get in on some precipitation even this far north. And indeed like you said, the other models do show that signal for moisture hanging around, just not as pronounced as what the GFS had. We’ll have to see where the trends go with this over the next couple of days. I was actually surprised at how quiet this next week looked in the modeling; we typically won’t have a week that quiet around here in the northern mountains unless full blown arctic high pressure moves in and leaves us in that dry, frigid air. Even during that very slow week before this past one, we still had 2 to 3 inches from those very weak bread and butter systems. There’s almost always a little something that pops up, and the mountains do their thing to at least get some flakes out of it.

Yeah, awesome upslope-land views over the past few days. This was definitely on my mind when I was out for a tour yesterday. The consistent snows and temperatures we’ve had over the past several days certainly had me pretty certain that the snow quality was there for lift-served skiing, but the appearance of your arctic hounds led me to go touring instead. When I saw highs in the single digits F for Bolton Valley yesterday, there was no way I wanted to sit still on the lifts in the wind vs. generating my own heat down in the protection of the forest. I got up to the Village around midday, and temperatures were indeed in the mid-single digits F as the forecast had suggested. Between all the backcountry touring and Nordic folks that I saw, there were plenty of people out on the lower trails, but farther out into the higher trails by the Bryant Cabin, I saw probably a handful of groups. Overall, you could tell by the vibe that people felt it was great weather for these types of activities. The additional 4 inches of fresh champagne that the resort had picked up really just served to top off the already crazy levels of fluff that covered everything. I saw some great views as soon as I arrived in the Village, so before gearing up for my tour, I took a quick walk around the Village and grabbed some scenic shots of the snow. Once I started my tour and got into the forest, the amount of snow everywhere was just crazy – it was caked so heavily on the trees that you were surrounded by it on all sides. Starting up the Bryant Trail was like walking into some sort of white cathedral. I made depth measurements of the snowpack during my tour, and I found generally 26-27” around the 2,000’ level, and many spots that are getting dangerously close to 40” up near 3,000’. That’s pretty consistent with what the Mt. Mansfield Stake is showing. At the start of my tour off Heavenly Highway I was on some steep, 30+-degree slopes, and I was setting off sloughs that definitely spoke to the relative snowpack instability from the continuous day after day after day of snows without consolidation. I was perfectly safe where I was the very dense (too dense for great turns where I was exploring actually) forest, but I immediately though about how I wouldn’t want to be exposed in the ravines. So I guess it wasn’t entirely surprising to come to the forum to find a conversation about slides in Tuckerman. A few shots from yesterday’s tour:

I’ve been checking it out for our site for a few years now, ever since Ginx pointed it out and the fact that CoCoRaHS stations are in there. I’ve found it generally to be quite good for my site. It definitely takes the empirical observations into account at times (see the data assimilation points in the plot) to at least augment the modeling, but they don’t seem to just immediately lock the modeling to the actual observed data points when they do the assimilations from what I’ve seen (and as you can see in the plot below). I don’t really follow the data for other sites to see how well its modeling reality, but I bet the meteorologists can provide more input on that. I’d suspect results are going to be better with the modeling if you’ve got consistent data input, such as at a CoCoRaHS or co-op site, but it’s not too hard to imagine that if you’ve got a site with zero empirical observations and 100% modeling (I’m not sure if they do that), the output could get quite far off from reality.

I hadn’t really checked the weather models much this week aside from a quick look in the short term to see if anything had changed for the bread and butter storms, but I just took a look ahead and I’m seeing some potential snow in our area on Tue/Wed? If it was just one model I’d guess it was nothing of note, but I just saw it on multiple models. The GFS seems to be trapping some moisture that hangs around for quite a while after the system passes. I guess we’ll see what the BTV NWS thinks about it in their afternoon AFD.

Oh, and the NOHRSC output does have a standard panel that tries to get at the snowpack layers (lower plot in the image below), and I think it’s roughly getting at the layers that PF is talking about. You can see the modeled settling in the very top layer of fluff, and at the very end of the modeling timeline what even looks like some compression in that lowest layer of faceted snow he mentioned:

Yeah, the snowpack topped out at ~18” here the other day, and it’s dropped a couple inches to 16” now. My last snowpack liquid analysis was on the 19th, when then snowpack had just shy of 2 inches of liquid in it. Based on what we’ve picked up in the past several days, we’re probably in the range of ~2.5” of liquid at this point? As I mentioned the other day, it looks like the NOHRSC modeling for our site (plot below) had the snowpack SWE a tad high because some of the Winter Storm Malcolm liquid when the temperatures were marginal probably percolated down through the snowpack here, and their modeling didn’t seem to account for that. They have now done a couple of assimilations of the actual data I’ve sent in (green lines on the plot), and I think they’ve reigned in the disparity a bit. The NOHRSC plot currently has our average snowpack density here at around 20%. As PF mentioned, there’s plenty of fluff on top in the form of dry snow from these recent days, so I know we’ll see some settling of that. But, there’s that very stout middle layer from the dense part of Winter Storm Malcolm that won’t settle much, and then a sugary/faceted layer below that representing the previous snowpack. I think it’s generally going to be the top portion of the pack settling as we go forward, so we’ll settle some, but it’s not as if the snowpack depth will get cut in half.

Ahh, it becomes much clearer now why Phin has been so very insistent about having that snowpack in place at the house. I’d be stressed as well if my main spiritual/emotional outlet during the winter was in jeopardy. We’re definitely glad he’s got the new spot in NNH.

LOL, don’t worry bwt, “epic” is totally subjective and fine to use whenever you want. As a skier, let’s just say that’s clearly a good sign if the word is even coming up in the conversation. Indeed, as PF alluded to, as a scientist, what I like about this forum is that one can dive into the data and actually get a sense for where things really stand vs. just simply relying on hype, poor memory, weenie hyperbole, agenda, opinion, anecdotes, recency bias, etc. etc. And I love that the meteorologists on here will often pull out real data to shut down misconceptions. I get it that for many folks, the forum is more focused on the entertainment aspect, and that’s great, but I really like the science/data-driven side a lot. A great analogy for what the forum is like from my perspective (and I mean the main threads for the most part, the NNE thread is pretty even-keeled), is like listening to Dr. Fauci talk about the COVID-19 pandemic on one hand, vs. listening to Donald Trump talk about the pandemic on the other. One of those presentations is more for show, publicity, entertainment, popularity, etc., whereas the other deals more with the nuts and bolts. One (you can probably imagine which one) is rather cringe-worthy from the perspective of someone who has been training and working in science for decades, and the other just clicks and makes sense. I’m clearly biased in my preference of course (Dr. Fauci was technically my boss during my years at NIAID), so it’s posts of that sort where I put a lot of my efforts. It is funny to think of us pulling out the data to tell folks how excited they should be, LOL. Hopefully I’m not overselling the past week with this one: