J.Spin

Well, this next winter storm has been deemed impactful enough to get a name, and it’s called Winter Storm Avery. It’s essentially wall to wall winter weather advisories and winter storm watches across NNE at this point as the advisories map below shows. The BTV NWS projected accumulations map has generally got 4-6” in the valleys and 6-8” along the spine of the Greens.

Event totals: 0.3” Snow/0.01” L.E. We’ve had a bit of snow in the air this evening, but it seems like today’s snow associated with lake enhancement moisture is done for the most part, so Details from the 6:00 P.M. Waterbury observations: New Snow: 0.3 inches New Liquid: 0.01 inches Snow/Water Ratio: 30.0 Snow Density: 3.3% H2O Temperature: 18.3 F Sky: Flurries Snow at the stake: 3.0 inches

For storms, I rarely wait for frozen material in the outer cylinder to melt – the recommended approach is to pour a known amount (measured by the inner cylinder) of hot water into the tube to melt the frozen material. Then, when you pour everything back out into the small cylinder to measure it (it may be multiple small cylinders full), you subtract the hot water you added. This process is the most challenging, and most often needed to begin with, when doing whole snowpack cores, since those can take a lot of hot water to melt. If time permits I like to let those thaw on their own, but sometimes I want to get the data out in a timely manner so I melt things down.

As long as everything gets into the cylinder (see important note about that below) it’s absolutely fine, and indeed the instrument is specifically made to do that. The outer cylinder is really the collection bore, with the inner cylinder added to amplify the height of the liquid column for reading to the nearest 0.01” with accuracy. Just collect via the outer cylinder and dump the contents into the inner cylinder to read to the nearest 0.01” for reporting. When I collect with just the outer cylinder, if it’s a situation where there’s water adherence to the inside of the cylinder (typically the case), I either squeegee that off, or simply add an extra 0.01” to what I get from the inner cylinder. I’ve measured the difference enough times now to determine that the adhered water on the inside of the large tube generally adds up to about 0.01”, so it’s simply faster to add that onto my reading vs. getting in there with a squeegee and bringing it all down. Do note that collecting snow in the cylinder is really not a great technique, depending on the level of wind, type of snow, etc. Ideally you want to do as much catching of snow on collection boards as possible. Due to the nature of flakes not always falling exactly vertically, the cylinder will often undercatch snowfall, and thus the amount of water you get will not be representative of what actually fell. The undercatch is not an issue for collection boards, so you really only want to use the cylinder for anything that’s just too liquid to be caught by your boards. For best results, you want both pieces of equipment on hand to cover all contingencies for mixed precipitation events.

Indeed, the best thing to do is simply switch the Stratus to winter mode. There are always going to be some messy storms where it’s going to be impossible to collect the liquid for the event from snow cores alone. If a storm has a rainy front end, or back end that melts the snow that fell, you’ll never be able to quantify that liquid if you don’t capture it in a gauge.

The precipitation at our site this morning was just flurries at observations time, but it eventually picked up to become an accumulating steady light snow. Checking on the source of today’s snow, it was interesting to find even the BTV NWS experts discussing that challenge in an AFD update. The origin of the snow was ultimately determined to be upstream lake enhancement moisture under cold air advection with help from upslope. There’s no doubt that the skiers and other winter recreationalists here in NVT are very lucky to have our BTV NWS crew staying on top of all things winter for us. Here’s a great quote from the recent update below: “What a wonderful problem to have in mid Nov, which is trying to find the off switch to the snow machine…” Of course, no, we’re not actually trying to find the off switch to the snow machine (we prefer to have that switch taped to avoid problems), but the sentiment is well taken. Area Forecast Discussion National Weather Service Burlington VT 638 AM EST Wed Nov 14 2018 .NEAR TERM /THROUGH THURSDAY/...As of 509 AM EST Wednesday...Have updated the forecast to expand chc pops across most of the dacks and the central/northern mountains of VT. What a wonderful problem to have in mid Nov, which is trying to find the off switch to the snow machine, light snow showers have been falling all night at slk. Little rusty in my identification of what is causing this precip, but combination of water vapor and ir satl tells the story. Weak lift from channeled vorticity is interacting with upstream lake enhancement moisture, along with strong caa is aiding in squeezing out the remaining moisture in favorable upslope flow, to produce narrow bands of light snow shower activity across northern NY into VT. Web cams indicate some light snow accumulation overnight, so have also bumped snowfall amounts up to a dusting to 0.5. Not a big deal overall, but thought an update was needed to capture the latest trends. This activity should decrease in areal coverage/intensity by 15z this morning.

Event totals: 2.7” Snow/0.64” L.E. Today’s additional snow was right in line with the density from the snow this morning; not fully saturated, but certainly quite wet. I was also impressed that the rain gauge managed to catch all this snow as well – the liquid in the gauge was perfectly in line with the liquid captured from today’s two board collections to a hundredth of an inch. Details from the 6:00 A.M. Waterbury observations: New Snow: 1.9 inches New Liquid: 0.45 inches Snow/Water Ratio: 4.2 Snow Density: 23.7% H2O Temperature: 34.0 F Sky: Light Snow (1-4 mm flakes) Snow at the stake: 3.0 inches

Event totals: 0.8” Snow/0.19” L.E. Details from the 6:00 A.M. Waterbury observations: New Snow: 0.8 inches New Liquid: 0.19 inches Snow/Water Ratio: 4.2 Snow Density: 23.8% H2O Temperature: 34.0 F Sky: Snow (2-12 mm flakes) Snow at the stake: 1.0 inches

I didn’t have enough time yesterday to send along an update, but I was able to get out for another ski tour at Bolton Valley, and the family was able to make it as well. With the cold temperatures, there really weren’t any substantial changes in the snowpack between Saturday and Sunday. The fluff that had fallen on the mountain later on Saturday had settled out on the lower mountain, so the melt crust there was more obvious than it had been, but the skiing was similar. The great skiing was still above 2,500’ where the snow had never been affected by warmth. This next storm should only add to what’s there, and the current forecast suggests it would be all snow at elevation. A few shots from yesterday:

I haven’t been able to find where they discussed the aspects of the upgrade yet, but that’s typically a nice sign of course. The discussion speaks of the strong dynamics in northeastern VT, and they’ve got the Winter Storm Warning covering everything up there. Looking at the projected accumulations map, the higher elevations didn’t get a big increase, but a lot of the lower and middle elevations seemed to. They bumped us into the 6-8” shading, and our point forecast generally reflects that, but we’ll have to see how things go in the lower mountain valleys.

Yesterday morning we picked up a final tenth of an inch of snow to finish things off from that weekend system, but early this morning I got a text alert that we were under a Winter Weather Advisory, so it’s time to start thinking about the next event. A quick look at the BTV NWS forecast discussion, advisory text, and some point forecasts suggests that for NVT they’re thinking 3-6” in the valleys and 6-12” for the mountains. The latest advisory and projected accumulations maps are below:

Around here in the Northern/Central Greens, I’d say the more lenient resorts with respect to people skinning for turns would be Mad River Glen, Bolton Valley, Smugg’s, and Jay Peak. For the past several seasons, Sugarbush has seemed to be on the more restrictive side like most recent policies posted by Stowe, but even if you don’t visit those two resorts, that still leaves at least two eastern slope and two western slope options in the area. Ideally it’s best to have them all in play, since some areas can do better than others in any given storm cycle. I’m sure people are skinning for turns at Sugarbush and Stowe (PF noted the presence of cars), it’s probably just done a bit more covertly when the more restrictive policies are in place. Wherever you go though, just be respectful of the mountain, and especially the mountain operations that are going on. Ideally it’s just best to stay well away from any sort of work that’s being done (grooming, snowmaking, etc.), so if you can, choose a touring route that doesn’t go near any of that. And I’m glad you’re making use of the reports I send out. With mountain weather and snowpack conditions often changing so rapidly, and access to specific data from the higher elevations hard to come by, it can be really tough to know what’s going on up there. Getting that beta out there for others to use is definitely one of the key reasons for putting the reports together. When the snow is good, I’m typically going to be out there for recreation and exercise anyway. I’m always going to write up something and get photos to put in my ski journal/website anyway, and getting the weather and snow/weather conditions in there is an important part of documenting the event.

Event totals: 1.2” Snow/1.01” L.E. Details from the 6:00 A.M. Waterbury observations: New Snow: 0.4 inches New Liquid: 0.01 inches Snow/Water Ratio: 40.0 Snow Density: 2.5% H2O Temperature: 28.4 F Sky: Flurries Snow at the stake: 0.5 inches

Great stuff PF, it’s always nice when you post these analyses showing the impressive terrain effects along the spine. What a barrier the Greens can be.

I was able to head back up to Bolton Valley this afternoon for a ski tour, so I can add to my accumulations profile from that I sent along earlier today. The readings above 2,000’ may have been boosted a bit by today’s additional snowfall, but they generally synched up fairly well with my observations from this morning. Here’s the full new snow depth profile: 340’: 0” 1,000’: Trace 1,200’: 1” 1,500’: 3-4” 2,000’: 6-8” 2,100’: 8-9” 2,500’: 10-12” 3,000’: 12-14” I did get readings as high as 16” on the upper mountain, and one drifted spot with 20”, but I’d say 12-14” is a decent measure of the top end I found. It seemed like there was some old snowpack up high, but I don’t think it interfered with measurements of the new snow because it should have been pretty solid by now. Even base temperatures had dropped into the 20s F when I was up there in the midafternoon, and my thermometer was showing 19 F when I was up at the Vista Summit, so the snow wasn’t wet at all. Below ~2,500’ there was a thick layer in the snowpack that was only an issue in wind scoured areas. I’m not sure when that developed (maybe during the warmest part of the storm), but today’s additional snow sort of mitigated that, at least with the 115 mm skis I was on. Above 2,500’ it didn’t seem like that layer was even present, and turns were fantastic in midwinter snow. There’s definitely a nice density gradient to give you those easy powder turns with ample protection below. With tonight’s temperatures, the only enemy would be wind, so the good snow should be there a while for those who want get after it. Below, I’ve added a few pictures from today at the mountain:

Event totals: 0.8” Snow/1.00” L.E. Details from the 6:00 P.M. Waterbury observations: New Snow: 0.3 inches New Liquid: 0.03 inches Snow/Water Ratio: 10.0 Snow Density: 10.0% H2O Temperature: 35.4 F Sky: Light Snow (1-3 mm flakes) Snow at the stake: Trace We picked up an additional 0.3” of snow with today’s various rounds of snowfall activity, and it’s actually been fairly active this evening with the WNW flow of moisture.

Since Bolton Valley doesn’t have its webcam in operation yet, and they’re not making immediate snow reports, I didn’t have a sense for how much snow they’d gotten out of this storm. With the way this storm seemed to favor the eastern slopes around here, I was wondering about what the western slopes accumulated, so I quickly popped up to the mountain to assess the potential for turns. Any snow accumulations disappeared as I dropped down into Bolton Flats, and at the Base of the Bolton Valley Access Road (340’) there was no accumulation, and there weren’t any signs of white until I hit 1,000’. So I’d say that indeed, accumulating snow levels are definitely lower on the eastern slopes – snow at 1,000’ was about equivalent to 500’ here along the spine. The snow depths did eventually did go up dramatically with elevation however. Here’s the elevation profile I found for depths of new snow: 340’: 0” 1,000’: Trace 1,200’: 1” 1,500’: 3-4” 2,000’: 6-8” That’s as high as I went, but indeed the snow depths increased rapidly above 1,500’. It was pounding huge flakes of snow up there as well, so they’re certainly picking up more. Hopefully I’ll head up for a ski tour, and if I do I’ll report from higher up as well.

The precipitation here at observations time this morning was just a mix of mist/drizzle/light rain, but about 15 minutes ago we had some ticks of sleet, and then snow began to appear. It looks like we’re getting into the backside portion of the event now with the anticipated LES/upslope snow, which is right in line with the BTV NWS forecast discussion. They suggest the potential for an additional 2-4” in the Mansfield to Jay Peak region: Area Forecast Discussion National Weather Service Burlington VT 627 AM EST Sat Nov 10 2018 .NEAR TERM /THROUGH SUNDAY/... As of 627 AM EST Saturday...Forecast continues to play out well with primary low pressure tracking northeast into southern Quebec early this morning while a secondary low tracks over Cape Cod. Through mid-morning rain and drizzle will transition to orographic and lake effect snow showers as the primary low drags a surface cold front through the region. As far as snow accumulations go, they`ll be localized to the western Adirondacks and portions of the northern Greens where upslope conditions are favored, but overall moisture thins through time so only expecting additional accumulations of a dusting to 2 inches below 2000 feet, with the summits of the northern Greens from Mansfield to Jay Peak perhaps picking up an additional 2-4". Based on the fropa timing, temps won`t budge too much today, peaking mid-day in the mid 30s to around 40.

Event totals: 0.5” Snow/0.93” L.E. Details from the 6:00 A.M. Waterbury observations: New Snow: 0.2 inches New Liquid: 0.10 inches Snow/Water Ratio: 2.0 Snow Density: 50.0% H2O Temperature: 34.9 F Sky: Light Rain/Drizzle/Mist Snow at the stake: 0.5 inches

Event totals: 0.3” Snow/0.47” L.E. At some point between 5:00 P.M. and 8:00 P.M. the precipitation was fully over to snow, but accumulations still took a while to take hold with air temperatures in the mid to upper 30s F here at 500’. I made an analysis of this first part of the storm now that snow is accumulating more easily, and the liquid from the snow clogging the upper portion of the rain gauge was right in line with the liquid from the snow on the snowboard. The accumulated snow thus far is not surprisingly quite sloppy and saturated with water. Details from the 9:00 P.M. Waterbury observations: New Snow: 0.3 inches New Liquid: 0.16 inches Snow/Water Ratio: 1.9 Snow Density: 53.3% H2O Temperature: 34.3 F Sky: Light/Moderate Snow Snow at the stake: Trace

When I got to the Waterbury area around 4:30 P.M. this afternoon the precipitation here at around 500’ was rain, but there were clearly crystals in the raindrops visible on my windshield. Since then the precipitation has changed over to a more obvious mix of rain and snow and it’s just starting to accumulate on elevated surfaces.

With their afternoon update the BTV NWS added a Winter Weather Advisory to Northeastern and Central Vermont along the spine, with a bit of a bump in accumulations there to the 2-6” range. The emphasis for accumulations is still on elevations above 1,000’ or even 1,500’, but our point forecast at 500’ did get a bump to 2-4”. I suspect any accumulations down low will depend on snowfall rates etc. On the projected accumulations map, the higher elevations in the area were dropped into the 4-8” range, which is consistent with the updated point forecast for Mansfield.

Well, we’re getting to the stage of this upcoming storm where it’s time for maps. There aren’t any winter advisories in Vermont, but there are some in the Adirondacks and over in Coos County. In Vermont there’s a Hazardous Weather Outlook for this for this event, mentioning 2 to 4 inches of snow accumulating on elevated surfaces east of the Champlain Valley, and 4 to 8 inches of snow above 2,000’. The Hazardous Weather Outlook also mentions the potential midweek storm, because the BTV NWS feels additional accumulations are possible there. The point forecast for our site has us in the 1-3” accumulation range, and in the projected accumulation map the peaks of the Greens are in the 8-12” range, which generally jives with the point forecast for Mansfield.

After the way things seemed to work last year, my advice on uphill at Stowe was to simply avoid it altogether once any mountain operations were taking place. With opening day set for November 16th, that essentially means any day now, or basically as soon as it’s cold enough to resume snowmaking. I decided to check on the formal uphill policy on the website: https://www.stowe.com/the-mountain/about-the-mountain/mountain-safety.aspx Here are a couple of relevant excerpts: Important Announcement - November 6, 2018 - TBD Please be advised that for the safety of our general public, guests and employees, uphill access will not be permitted during the early season due to mountain operations and snowmaking work taking place at the resort. Stowe Mountain Resort will open for uphill access when early season operations are complete, and when the resort has adequate terrain to safely permit these activities. So I figured once the mountain opened, that was it, no hiking for turns until they deemed “early season” was over (whenever that might be). But lower down on the page there’s also this: Mountain Closed for Uphill Access During Pre-Season Operations Although the mountain is closed for the season, mountain operations continue and skiing/riding is forbidden at this time. The way that’s written (closed for the season is usually written in the spring), it suggests they’re not even allowing any pre-season/off season hiking? I can only imagine how this policy is received by the Stowe town locals. It’s hard to know which of these policies are actually enforced, and which are actually just for legal C.Y.A. purposes by the resort. Perhaps things are back to the way it used to be long ago with a “don’t ask, don’t tell” type of policy, or guerrilla-style outings. I don’t think we actually had any really potent storms ahead of the lifts opening last fall, so if these next couple of systems deliver something substantial, I guess we’ll just have to see how it actually plays out at the mountain.