J.Spin

I commented on season snowfall and snowpack depth in the previous discussion, but I didn’t mention snowpack start date because I’d been meaning to respond to this discussion. With close to an inch of liquid down from the this past storm, this could easily be the actual start to the winter snowpack for some valley locations. Roughly average temperatures and a typical assortment of storms (even with some rain or mixed precipitation) wouldn’t really knock out a snowpack of this scale, especially since the snow is fairly dense and dry right now, and has the potential to absorb some liquid. Obviously a large enough warm-sector storm could do it, but it would have to be one of those with little to no front side or back side snows. The current snowpack here started back on the 23rd, which would be about a week ahead of average, but the data say that’s well within one S.D. (15 days), so it’s very typical. We’re also very close to the mean start date now anyway (Dec 2). I’d argue the upper mountain snowpack is here to stay at this point based on what I found yesterday at Bolton Valley. There’s already a couple inches of liquid in there, so it would take a highly anomalous system to melt every last bit of that down.

I don’t record temperature stats, but I’d take 20s F and prodigious snowfall all season long over any sort of single digits with respect to “best” wintry weather. I guess cold temperatures are good for snowmaking, forming ice, etc. But also remember that if cold temperatures persist too much in the region, they’re going to cool off the Great Lakes quicker and reduce the potential of that moisture source. In terms of the snow aspect of wintry weather, there really shouldn’t be any fears about this being some sort of anomalous stretch that would be hard to match – the data here say things are proceeding at a very, very… very average pace. Mean season snowfall at our site through today is 13.8 inches, and we’re currently at 13.6 inches on the season. Mean snowpack depth here is 3.3 inches, and we’re at 5.0 inches, so in those respects our pace and recent weather seem quite typical. The usual deterministic caveats apply, but a quick zip through the GFS shows the potential for eight systems in the next couple of weeks, all of which have chances for snow (this is NNE, and we’re heading into December), so it really doesn’t look like we’re simply going to move into a period of benign fall weather.

Earlier I sent along the accumulations profile I encountered today in the Bolton Valley area, and I’ve got a few images below to go with a snow update. As noted, the snow we received around here was generally dense, and it put down a substantial addition to the base on the slopes. We picked up over an inch of liquid at our site in the valley from this storm, and I’d say the slopes of Bolton easily picked that up as well. It feels like there’s at least an inch of L.E. at the base elevations, and probably something like two inches of L.E. up high. Some of the higher elevation snowpack could have come from previous events, but in any case, that’s a substantial amount of L.E. in place. There were a couple inches of drier upslope snow to finish off this storm cycle, but the bulk of it was that denser snow, and that’s definitely what set the tenor of the skiing. There were no concerns about hitting anything under the snow on trails without any overt obstacles like large rocks, and any terrain that was smooth up to the level of single black diamond pitch was fine to ski unless it was wind scoured. In fact, the snow was too dense for skiing any low angle terrain, so you really had to be on moderate to steep terrain or you would be bogged down and just have to straight-line to maintain speed. Skiing on terrain with the right pitch was quite good though, and you could carve right into the powder and just let the skis surf.

Below I’ve got the accumulations profile I found this morning at Bolton. What I found is definitely more than what they’ve got in their snow report, but they did indicate they had trouble with blowing at their stake. It’s possible my measurements were getting down into existing snowpack, but it seems like that should have been consolidated from recent temperatures. The backside upslope snow was also coming down while I was out there today, so that likely added a bit to the totals. 340’: 4” 1,000’: 5” 1,500’: 7” 2,000”: 10-12” 2,500’: 13-14” 3,000’: 14-16”

Event totals: 7.1” Snow/1.09” L.E. This morning’s snow certainly seemed like upslope precipitation, and the radar had that look. The density speaks to its nature, so Coastal got the treble he needed. We’re partly cloudy with some flurries out there now, so if this storm is over, we certainly ended up in the 5-10” range that was in our BTV NWS forecast. There are some echoes building off to the west on the radar, so we’ll see if they have any precipitation that makes it over this way. Details from the 12:00 P.M. Waterbury observations: New Snow: 0.9 inches New Liquid: 0.03 inches Snow/Water Ratio: 30.0 Snow Density: 3.3% H2O Temperature: 27.9 F Sky: Flurries/Partly Cloudy Snow at the stake: 6.0 inches

Event totals: 6.2” Snow/1.06” L.E. Details from the 6:00 A.M. Waterbury observations: New Snow: 1.2 inches New Liquid: 0.13 inches Snow/Water Ratio: 9.2 Snow Density: 10.8% H2O Temperature: 24.4 F Sky: Light Snow (1-3 mm flakes) Snow at the stake: 5.0 inches

Event totals: 5.0” Snow/0.93” L.E. Details from the 12:00 A.M. Waterbury observations: New Snow: 3.9 inches New Liquid: 0.46 inches Snow/Water Ratio: 8.5 Snow Density: 11.8% H2O Temperature: 29.3 F Sky: Snow (1-5 mm flakes) Snow at the stake: 4.0 inches

There’s definitely some paste love at this stage, and kudos to this system for what it’s put into the base already – data from our site indicates a half inch of L.E. thus far down here in the valley. If this snowfall gradually dries out in typical storm cycle fashion, we know what that means.

Event totals: 1.1” Snow/0.47” L.E. Details from the 6:00 P.M. Waterbury observations: New Snow: 0.6 inches New Liquid: 0.16 inches Snow/Water Ratio: 3.8 Snow Density: 26.7% H2O Temperature: 32.7 F Sky: Snow (1-10 mm flakes) Snow at the stake: 0.5 inches

Yeah, I didn’t get to see it fall, but I just happened to check the snowboards before going to bed and saw the accumulation. I did see a line of echoes on the radar heading off to the east. The snow was dense (16.0% H2O) and didn’t really change the depth of the snow at the stake because I think it just crushed that drier snow down, but this addition is a bit better in terms of the robustness of the base. We’ve had a little mist/sprinkles this morning, but just a trace of additional liquid. Event totals: 0.5” Snow/0.08” L.E. Details from the 12:00 A.M. Waterbury observations: New Snow: 0.5 inches New Liquid: 0.08 inches Snow/Water Ratio: 6.3 Snow Density: 16.0% H2O Temperature: 32.5 F Sky: Cloudy Snow at the stake: 0.5 inches

The BTV NWS has made their update with Winter Storm Warnings along the spine of the Northern Greens as well as Winter Weather Advisories over various sections of the state. They have adjusted the projected accumulations map to include some 18-24” shading in the Bolton Mountain to Mt. Mansfield, and Jay Peak sections of the spine. The Mt. Mansfield point forecast is topping out right around 24”, so that’s consistent with the map. Area Forecast Discussion National Weather Service Burlington VT 341 PM EST Thu Nov 25 2021 .SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/... As of 340 PM EST Thursday... ...Winter Storm Warnings and Advisories in Effect for Portions of the North Country Friday afternoon Through Mid-day Saturday... Burying the lead, snow totals will vary widely based on location and elevation. In the deeper valleys where no headlines are in effect a generous 1-3" is expected while elevations above 1000 feet outside of the upslope regions will see 2-6". In the upslope regions 4-8" is likely up to 1000 feet with 6-10" further up the slope to 2000 feet with 14-20" likely at the highest elevations of Jay Peak, Mt. Mansfield and Mt. Ellen. Further south along the spine of the Greens 8-12" is likely near the summits such as Mt. Abraham and Killington. Lesser amounts are expected in the Adirondacks, but still a good 8- 12" in the high peaks.

Well, it seems like monster runs appearing closer to the system is a good way to go. We’ll see what the BTV NWS has to say in their next AFD.

The BTV NWS has Winter Storm Watches up now for the system affecting the area over the next couple of days. Both the discussion and the projected snowfall map suggest accumulations topping out in the 12-18” range at elevation in the Northern Greens. Area Forecast Discussion National Weather Service Burlington VT 627 AM EST Thu Nov 25 2021 .SHORT TERM /FRIDAY NIGHT THROUGH SATURDAY/... QPF forecasts have remained steady with this cycle, and with that, there`s been little change to the forecast liquid and snow amounts over the forecast area. Amounts between 4" and 10" are expected within the winter storm watch area, with northern summits of the Greens seeing locally higher amounts in the range of 12-18". We will also see snow accumulations across the valley floor, especially if the surface low over southern New England develops quickly. For now, have indicated 0.5" to 3" across most of the lower valleys, though there are a few spots with 4" amounts, particularly north.

Event totals: 4.0” Snow/0.10” L.E. These above totals should be it for this event – the streamers seemed to wind down last night around 1:00 A.M. and the sky is just partly cloudy now. Details from the 6:00 A.M. Waterbury observations: New Snow: 0.6 inches New Liquid: 0.01 inches Snow/Water Ratio: 60.0 Snow Density: 1.7% H2O Temperature: 21.7 F Sky: Partly Cloudy Snow at the stake: 2.5 inches

Event totals: 3.4” Snow/0.09” L.E. Details from the 12:00 A.M. Waterbury observations: New Snow: 2.5 inches New Liquid: 0.05 inches Snow/Water Ratio: 50.0 Snow Density: 2.0% H2O Temperature: 23.9 F Sky: Light Snow (2-20 mm flakes) Snow at the stake: 2.5 inches

It’s been pretty steady here, not inch per hour stuff, but probably ½“/hr. stuff. This evening has definitely been the most productive period of the day though, both in terms of snow and L.E. The next analysis for our site would be at midnight, so we’ll see where things stand, but I think we’re at about 3” for the storm thus far. We’re used to mountain magic, but this is a bit more potent than the forecasts would suggest - these bonus snows for the mountains and valleys are great when there’s not actually a “storm” around. The streamers are certainly laying down some accumulations where they’re hitting:

LOL, yea, that’s apparently been the latest weenie attempt at a pejorative for the mountain climates. The whole effort is obvious, but whatever helps entertain them through the drudgery I guess.

It actually was sort of a mystery at first, and it probably wouldn’t have been too big a deal if it hadn’t been quite as widespread and persistent. Once the BTV NWS AFD links started working, they did talk about it in a couple of spots: NEAR TERM /THROUGH WEDNESDAY/... As of 944 AM EST Tuesday...With the cold air mass now in place, flurries are being squeezed out of a shallow cloud layer in portions of the Adirondack region and northern Vermont. SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY NIGHT/... As of 322 PM EST Tuesday...heading into Friday evening/night as the upper low shifts east and phases with offshore shortwave energy (which coincidentally is what`s causing snow showers today), it`s blocked by a 1040mb high parked in the northern Atlantic. But watching that stuff just plow into the spine all day, it does leave one scratching the head a bit with the inclination to still just chalk it up to…

We’ll probably have a bit more in the near future – the radar looks like it’s ramping up a bit the way it did earlier this afternoon.

Event totals: 0.9” Snow/0.02” L.E. We had continued snow in the afternoon here at our site to about the same tune as the morning. I headed to Burlington in the afternoon on some errands, and snow accumulations really dropped off pretty quickly west of the pass here – Bolton Flats had just an isolated dusting in areas where the snow had collected. There really wasn’t much accumulation to note in the Champlain Valley, but the views were great. You could see areas off to the south and east with some breaks in the clouds, the greater Burlington area was cloudy with occasional flakes and light snow showers, and then off to the east the mountains were socked in with snow. In town it definitely felt like one of those November holiday types of days with the snow and people ramping up for Thanksgiving. Details from the 6:00 P.M. Waterbury observations: New Snow: 0.4 inches New Liquid: 0.01 inches Snow/Water Ratio: 40.0 Snow Density: 2.5% H2O Temperature: 25.0 F Sky: Light Snow (2-5 mm flakes) Snow at the stake: 0.5 inches

The BTV NWS did make an update to their discussion to better reflect today’s conditions: Area Forecast Discussion National Weather Service Burlington VT 100 PM EST Tue Nov 23 2021 NEAR TERM /THROUGH WEDNESDAY/... As of 100 PM EST Tuesday...Flurries have become more of a snow shower with a powdery dusting seen in parts of northern and central Vermont during the late morning into early afternoon. Have added mention of snow showers into much of this area, but little impact is expected with negligible liquid equivalent and modest wind and visibility restrictions.

Event totals: 0.5” Snow/0.01” L.E. This event wasn’t really in the forecast, but it’s definitely putting down a fresh layer of white and making the most of the available moisture thus far. We had a half inch down at noontime, but there’s been almost another half inch since then. The sub-freezing temperatures even down into the lower valleys at midday is clearly helping with the efficiency of accumulation. Details from the 12:00 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: 27.9 F Sky: Light Snow (2-15 mm flakes) Snow at the stake: 0.5 inches

I was able to get the latest BTV NWS AFD that discusses all the snow that’s around today. It appears that the snow is associated with an upper-level trough moving slowly across the area with weak forcing and low-level moisture. They could certainly update the discussion though, because the snowfall around here is more robust than that text would suggest. It was on and off snow showers earlier this morning with even some occasional breaks of blue sky, but now it’s wall-to-wall snow, with reduced visibility at times. I was just back in the center of town and it’s the same thing there. The precipitation is still light, fluffy snow, so I don’t expect they’ll have to worry about road conditions, but with the radar showing that there’s more moisture upstream, these conditions will probably continue for a bit. Area Forecast Discussion National Weather Service Burlington VT 945 AM EST Tue Nov 23 2021 NEAR TERM /THROUGH WEDNESDAY/... As of 944 AM EST Tuesday...With the cold air mass now in place, flurries are being squeezed out of a shallow cloud layer in portions of the Adirondack region and northern Vermont. With sub-freezing surface conditions, seeing some very light accumulation of snow, including on high elevation roads in Westfield, Canaan, and Buels Gore this morning. Previous Discussion... Upper level trough will be slow to move across the area today and is not expected to exit the region until tonight. Weak forcing and some low level moisture is helping to enhance some cloud development over the area and there is also quite a bit of cloud cover upstream. As a result have added a bit more cloud cover to the forecast and even threw in a few flurries over the higher terrain in northern Vermont.

There was nothing falling at observations time this morning, but in the past 10 minutes or so, a fresh round of flakes has begun to fall. I hadn’t noticed until this morning that our high temperature isn’t even expected to get out of the 20s F today, so there’s been no issue with accumulation. Unfortunately with the way the forecast discussions are not up to date on the BTV NWS site, I can’t get their thoughts on the origin of this current precipitation, but it’s certainly visible moving in on the radar. There’s a bit more upstream in NNY as well. I’m just going to call it a minor disturbance coming in from the northwest for now until the forecast discussion issue is fixed.

Event totals: 0.2” Snow/0.19” L.E. The weather seemed to clear out by yesterday evening, so the totals above are what I recorded here for this most recent system. It definitely whitened up some of those lower slopes that had lost their cover over the past few days.