J.Spin

These next couple of systems (a smaller one on Friday, and then a larger one starting Sunday) have generally looked like mixed precipitation, but the back side of the second one seems to consistently show snow potential in the models. It’s interesting that some models like the ECMWF and CMC show more wintry potential in that second system, but the BTV NWS doesn’t even mention anything about that in their discussion, so I wouldn’t lend it much credence at this point. For now, I’d certainly watch that Monday/Tuesday period for potential ski options depending on how the back side of the storm cycle plays out.

LOL, I was actually going to respond to the comment because that climate literally exists, and we have the data for it. The annual snow totals would be quite variable depending on elevation and mountain aspect, but you’d probably be looking at ~100” at a minimum. That is unless you’re thinking warning-level snows every few days. Annual snowfall would need to be well into the hundreds of inches to pull that off, and most of the places I can think of with big snow totals like that don’t typically have their storms quite that frequently. My best guess at a place that might be able to do it consistently would be the mountains of Hokkaido, but the more coastal ranges of British Columbia might be able to do it in some years with the right pattern. My numbers from the past 13 seasons indicate that we average 40 accumulating storms during that Dec 1st to Apr 1st period, which breaks down to a storm bringing some sort of accumulation almost exactly every 3 days on average. Mean snowfall during that stretch is 135.5”, so that equates to an average of 3.4” of snow per storm. Actually, Mt. Mansfield at elevation could be close to averaging a warning-level snow about every 3 days during that period, because the snowfall there is typically just about double what I record. Of course it doesn’t actually work out with a nice distribution of a medium-sized storm every three days because you get periods where the storms are really popping up, lulls, small storms, large storms, etc. Still, such a climate is really not that far-fetched. We’ve actually been talking about this a bit in the NNE thread because No Poles was wondering about the possibility of a quiet week on the snowfall front. A little bit of potential popped up on the models for tonight though, sort of in line with the snowfall frequency discussion.

Well, it was likely that things would pop up at some point, and it looks like tonight is the first one of those. It’s obviously tenuous because it’s not even indicated on every model, but it’s there on the CMC, ICON, ECMWF, NAM 3km, WRF-ARW, WRF-ARW2, WRF-NMM, RGEM, etc. The thoughts as of this afternoon from the BTV NWS indicate that it’s fairly minimal and likely at elevation, but at least a bit of accumulation is a possibility here in the northern mountains: .NEAR TERM /THROUGH TUESDAY NIGHT/... As of 315 PM EST Monday...Mainly a persistence forecast over the next 42 hours with new NBM/blended data incorporated into existing datasets. A cold front remains on track to cross the area through the early to mid evening hours with winds shifting from south/southwesterly to northwesterly in the 6 to 10 pm time frame. Little sensible weather is expected along the boundary other than a trend toward cloudier conditions and some spotty sprinkles/flurries across elevated northern terrain where spot accumulations of a dusting to perhaps a half inch will be possible above 1500 feet. It looks like we might be moving beyond this bit of a snowfall lull though, with the models suggesting a potential system for Thursday/Friday and then another on Sunday.

Actually, Jay Peak has some of their most recent seasons (since the ’09-’10) listed on their website: https://jaypeakresort.com/skiing-riding/mountain You can also use the Co-Op data from the Jay Peak base and correct for summit elevation as I mentioned, either one should provide some decent numbers.

You have to remember, most of the resorts around here are going to make their snowfall measurements near the summits, or typically from mid-mountain up (PF makes his upper mountain measurements at 3,000’, approximately 75% of the way up Stowe’s lift served vertical). It’s essentially experiences like what you mentioned above that cause people to bitch and moan about the resorts inflating snowfall numbers. I’ve only been to Wildcat a couple of times, so I can’t speak much about their reporting, but I’ve been to Jay Peak numerous times. The reality of that day is most likely that in the wee hours of the early morning on the Jay Peak day you mentioned, when a patroller or mountain ops guy made his measurement, there were 9 inches in one of their usual high elevation, protected leeward spots. There’s probably less in most spots on the mountain, especially with the way snowfall drops off with elevation. Then you’ve got a few hours of settling before the skiers actually get there and start skiing it, and voila, it looks like there’s half the snow they said there was. Resorts should, and many do, provide the range of depths from summit to base to correctly inform the public. They essentially can’t account for the settling unless they literally deflate their numbers, and it’s really hard to blame them for not decreasing their observed snowfall by some amount to somehow account for potential settling. PF typically tries to go conservative on his numbers when he feels he needs to because he knows these things. I can tell you that in many hundreds and hundreds of lift-served ski days here in VT, I’ve never been duped by the snow reports. I follow the snowfall around here extremely closely as most on the forum know, so I’m well aware that they’re reporting early morning depths, from high elevation spots, before settling. I typically even know the density of the snow that fell, and what sort of settling to expect. The average skier/rider doesn’t know all this stuff though, so what one ends up with are the typical stories of overinflated totals that you describe.

Ahh, OK, if they’re averaging near 200” in the Hermit Lake Shelter area that makes more sense – when you mentioned that it was over 100” less than the summit I figured that meant they were averaging <180”. And indeed, I think the Mt. Washington summit area could average something like 350” or so, but they just haven’t got a convenient protected, calm, high-elevation spot on the leeward side of the mountain to make the measurements the way they’re done here at the ski resorts (such as with PF’s setup).

Wow, I didn’t know they’d started monitoring snowfall at the Hermit Lake Shelter area. How on earth are they measuring over 100” less than what the summit is measuring? That means they’re measuring what 150-175” of snowfall. That’s not all that different than what I record here at 500’, and just doesn’t seem to make sense for a site at 3,875’ in the Whites unless they’re in some sort of horrible shadow area. Is that 100” – 350” range you mentioned above for the Jay Peak Co-Op site? If so, note that they’re numbers from the base elevation, so a 350” number is quite substantial. That would translate to ~574” at summit elevation based on the typical gradient. Was that 350” for 2000-2001? If so, that year the resort reported snowfall of 571”, which would actually be pretty much in line with what you’d expect near the summit. https://www.wunderground.com/cat6/Summary-US-State-Historical-Snowfall-Extremes

It’s good that you brought up those data, because actually, since people are typically loath to believe the resort snowfall numbers, the Jay Peak Co-Op numbers are some of the strongest (unbiased?) support for the 300”+ annual snowfall averages near the summits of the Northern Greens. Note that the ~1,840’ Jay Peak Co-Op site is actually at the base of Jay Peak. The 3,858’ summit is over 2,000’ higher. If one uses PF’s numbers from Mt. Mansfield (~200” @ 1,500’ = ~300” @ 3,000’), you get a roughly 16% increase in snowfall for each 500 ft. of elevation gain on the leeward side of the Northern Greens. So if you use the Co-Op data, you’d estimate 336” for annual snowfall on the leeward side of Jay Peak near the summit, which is not all that different from what they report. We know that Jay Peak Resort’s snowfall measuring is not considered the most meticulous in the industry, but if you assume the Co-Op numbers are decent, then that certainly puts their summit snowfall numbers in the ballpark. There’s an extensive discussion involving PF’s numbers here: http://www.firsttracksonline.com/boards/viewtopic.php?f=2&t=11837

When it comes to discussions of weather in different mountain ranges, windward and leeward geographic locations with respect to bodies of water can have significant effects, so there’s a lot of wiggle room with respect to “very similar” weather patterns. That topic aside though, the 280” number from Mt. Washington is measured at the summit (extremely challenging to do, but if anyone can do it, that crew can) whereas Stowe’s numbers are measured on the leeward side of the mountain where the resort is located. If Mt. Washington measured accumulations down in a relatively elevated leeward spot like Tuckerman Ravine, I bet the numbers would be higher.

It actually took several years of investigation to figure out that the biggest joke is actually that Mansfield Co-Op “snowfall” number. The determinations of “new snow” are actually made by sticking a ruler in a rain gauge. And, apparently it’s one of those 24” tall rain gauges because if there’s been more than 24” of snow since it was last emptied, they simply report 24” for the accumulation. You don’t have to take my word for it though. Stowe Mountain Resort has gotten extremely diligent with their snow measurement over the past decade. They got a guy there that even works with the BTV NWS and monitors a snowboard at around 3,000’ or so. I think he’s so diligent that he even takes pictures of every snowfall measurement to document the numbers, but I’m not 100% sure about that. I’m sure we can get in touch with him to bring him in on the conversation though. Also note, unlike for Mt. Washington, the resort numbers from the Northern Greens resorts typically don’t even include snowfall outside the ski season, so depending on the resort’s season, the numbers aren’t including October, early November, late April, and May snowfall.

Bolton, Smugg’s, Stowe, Jay Peak; basically spots above 3,000’ in the Northern Greens. Averages I’ve seen in the Whites are 160” at Cannon, 200” at Wildcat and Bretton Woods, 250” at Balsams, and 280” at Mt. Washington, but I’ve never seen any 300”+ averages report there.

It’s funny that you ask that, because it was sort of on my mind as well as I’ve looked at the models over the past couple of days. It’s rather unusual to even be asking that question around here, especially in December. It’s our snowiest month with respect to # of storms – we’re averaging between 11 and 12 accumulating storms for December over the course of my data set. That means we’re typically looking at some sort of storm or event every 2 to 3 days. Between moisture off the Great Lakes, of course the Atlantic in larger systems, and the frequency of shortwaves, fronts, and whatever else passes by, there’s almost always something in queue to potentially freshen up the slopes. So unless we’re entrenched in arctic cold, seeing calm weather for a week isn’t very typical. When I posted that list of potential storms the other day in the thread, the ones for Sunday and mid next week were of course the most tenuous, and they’re actually still there on the models, but they’re just a bit too far north to affect us. The SNE guys like to joke that essentially if a moose farts up here in the upslope areas we get snow, and it’s sort of true in that almost any little ripple that passes through can spark something, but these next couple of shortwaves seem to be just a bit too far north based on what the models are suggesting right now. Some of the models do suggest the possibility of something midweek, but there’s certainly not consensus on it. The good thing is, up here in the mountains of NNE we’re in just about the best spot possible for stuff to pop up out of nowhere, or for little things to turn into something more. One of the factors in why the Northern Greens have these 300”+ snowfall averages is because they pull down more snow with each event, but I think an even bigger factor is the sheer number of events that come through. Those numerous “bread and butter” events really start to add up over the course of the season. It would be nice to get one or two of them for the holiday week.

Event totals: 2.3” Snow/0.07” L.E. Details from the 10:00 P.M. Waterbury observations: New Snow: 1.5 inches New Liquid: 0.06 inches Snow/Water Ratio: 25.0 Snow Density: 4.0% H2O Temperature: 10.9 F Sky: Partly Cloudy Snow at the stake: 4.5 inches

My phone just went nuts again and I got an updated one – it says it goes to 5:45 P.M.

Event totals: 0.8” Snow/0.26” L.E. I ran an analysis on the snow we’ve seen thus far this afternoon, and indeed it came in quite dry as PF was mentioning. We do have some additional snow falling now with the next slug of moisture coming into the area, so we’ll see what the evening brings with respect to any additional accumulations. Details from the 4:00 P.M. Waterbury observations: New Snow: 0.8 inches New Liquid: 0.01 inches Snow/Water Ratio: 80.0 Snow Density: 1.3% H2O Temperature: 27.5 F Sky: Light Snow (1 to 2 mm flakes) Snow at the stake: 4.5 inches

The NWS is certainly serious about these squalls – I got the full blown loud beeping alert on my phone, and my son just got home and said everyone else is getting them as well:

Well, we certainly know where the Vermont delegates would put their votes!

Yeah, liquid analyses will be interesting today. It looks like we’ve got some more potent pulses of moisture pushing into the area now:

I hadn’t really been thinking about the stake depths much yet this season, so thanks for the reminder. We haven’t quite hit that 24” threshold yet, peaking at 23” about a week or so ago, but this next event could certainly push it there. If we do hit it with this next round of snow, it would be later than the mean, but still well within 1 S.D., which stretches out to roughly the end of the month: Mean 12/12 Median 12/9 Mode 12/16 S.D. 18.8 days Last season it was hit was fairly early, with a date of 11/27 as indicated by the red star in the Mansfield Stake 24” data plot:

Event totals: 4.2” Snow/0.26” L.E. We had one final batch of snow move through in the late evening, and things have mostly cleared out this morning, so above are the final snow and liquid numbers for this event. Details from the 6:00 A.M. Waterbury observations: New Snow: 1.3 inches New Liquid: 0.05 inches Snow/Water Ratio: 26.0 Snow Density: 3.8% H2O Temperature: 20.5 F Sky: Mostly Clear Snow at the stake: 4.5 inches

Event totals: 2.9” Snow/0.21” L.E. Details from the 8:00 P.M. Waterbury observations: New Snow: 0.6 inches New Liquid: 0.07 inches Snow/Water Ratio: 8.6 Snow Density: 11.7% H2O Temperature: 24.8 F Sky: Light Snow (2 to 5 mm flakes) Snow at the stake: 3.5 inches

My next set of observations is at 8:00 P.M., so we’ll see where we are at that point. We picked up about another half inch since my earlier observations, but that larger flakes wound down and we’ve had just lighter snow with small flakes since then. If that banding that PF mentioned moves over toward the mountains here I suspect the snowfall intensity would pick up though:

Our location really gets lumped right in with that whole contiguous stretch of high elevations along the spine of the Central/Northern Greens, since the resolution isn’t quite high enough on that map. With that said, one distinct break point in the shading it that change from the more purple coloring into the pink/salmon coloring at 36”. The start of that zone would be 36-40”, which would actually be right on track with what I’ve recorded on the season thus far.

Event totals: 2.3” Snow/0.14” L.E. Details from the 2:00 P.M. Waterbury observations: New Snow: 2.3 inches New Liquid: 0.14 inches Snow/Water Ratio: 16.4 Snow Density: 6.1% H2O Temperature: 25.0 F Sky: Light Snow (4 to 12 mm flakes) Snow at the stake: 3.0 inches

The clouds dropped on the mountains a while ago, but as of ~9:55 A.M. we’re also starting to get some flakes here in Burlington.