J.Spin

Event totals: 2.0” Snow/0.18” L.E. The most challenging part of documenting this event so far has been whether or not the cold front was going to be a distinct from everything that is happening today, but it looks like this is all going to come together as a single event. We had some clearing last night after the cold front went through, but a few flakes lingered and we’d picked up another tenth or two through the late evening. With the fairly minor accumulations, there wasn’t much call to clear the snowboards at midnight, so I just left them until this morning. Obviously the snowfall picked up at some point overnight/this morning because there was 1.2” of additional snow at 6:00 A.M. observations. The BTV NWS is mentioning a number of different elements playing into the creation of the snow on the back side of this cold front, including a shortwave, lake moisture, and even convective snow showers. The boys told me that there was some fairly hefty snowfall yesterday when they got home from school, which was just around the point that the snow started accumulating down at our elevation. They reported that the snowfall was composed of huge flakes, which explains the lumpy nature of the accumulation I found on the boards at 6:00 P.M. Today’s snowfall has really been the most vigorous that I’ve seen. I was waiting for the bus in my car and the sky went quite dark as a squall moved in. In less than a minute I couldn’t see out of the car, and we picked up a quick shot of fluffy snow. Checking my web cam, it looks like we picked up a quick inch or so at the house with that one. Details from the 6:00 A.M. Waterbury observations: New Snow: 1.2 inches New Liquid: 0.03 inches Snow/Water Ratio: 40.0 Snow Density: 2.5% H2O Temperature: 24.1 F Sky: Light Snow (3 to 12 mm flakes) Snow at the stake: 1.5 inches

Event totals: 0.8” Snow/0.15” L.E. The precipitation was snow here from the start as far as I can tell, but based on the water in the gauge vs. the snow core, a little of the moisture was not captured in that snow during that period when there was no accumulation and things were melting on contact. There’s a bit more accumulation out there since the 6:00 P.M. observations, but the snowfall is very light with small flakes. The forecast has another 1-3” through tomorrow, so we’ll see how it goes. Temperatures should be colder though, with sub-freezing highs even in the lower valleys, so there really shouldn’t be much snow lost to melting. Details from the 6:00 P.M. Waterbury observations: New Snow: 0.8 inches New Liquid: 0.13 inches Snow/Water Ratio: 6.2 Snow Density: 16.3% H2O Temperature: 32.2 F Sky: Light Snow (1 to 3 mm flakes) Snow at the stake: 0.5 inches

I saw from my webcam that snow started up this morning at our place in Waterbury similar to here in Burlington, but I hadn’t seen any accumulation yet down at these elevations. I see now that we’re just starting to get accumulation at the house at 500’. Bolton Valley at 2,100’ at the main base looks like they’ve picked up an inch or so thus far via their webcam.

I see that it’s snowing now here in BTV - some of the flakes are a bit granular with rime on them.

Regarding tomorrow’s snow, I’ve got the latest projected accumulations map from the BTV NWS as of today’s afternoon update. They’ve got the mountain valleys around here in the 4-6” shading, which is probably a bit higher than what our point forecast would suggest, but this does include the additional potential snow on Friday, where they’ve increased PoPs associated with that snow shower activity. .SHORT TERM /FRIDAY THROUGH FRIDAY NIGHT/... As of 302 PM EST Wednesday...A shortwave will act to reinforce the eastern periphery of the upper level trough as it moves through the North Country on Friday. This will act to reinforce large scale ascent throughout the day with strong convergence ahead of this feature. In addition, temperatures in the boundary layer and through the entire column will continue to cool throughout the day. This will yield increasing low-level and mid-level lapse rates that will lead to additional snow shower activity throughout the day. Based on the latest guidance, PoPs have been increased across the forecast area to account for scattered to possibly widespread snow showers on Friday.

We’re starting to close in on this next potential snow event, and the BTV NWS is putting out their latest projected accumulations. Our point forecast currently suggests something in the 3-5” range from Thursday through Friday. The short term discussion below suggests accumulations a bit leaner than that down at our elevation, but it presumably doesn’t include any snow from the upper level shortwave behind that system that comes through on Friday. .SHORT TERM /7 PM THIS EVENING THROUGH THURSDAY NIGHT/... As of 336 AM EST Wednesday...Polar front and weak systems traversing along its periphery is on track to bring the first widespread snowfall to many parts of interior New England. Based on the latest data, about a 0.5"-2.0" are possible across the valleys, with 2-6" across higher terrain with locally higher amounts at the peaks. .LONG TERM /FRIDAY THROUGH TUESDAY/... As of 336 AM EST Wednesday...Friday morning should start out mostly dry with polar air advecting into the region. A subtle upper shortwave will dig behind the departing system. With sufficient moisture and 50-100 J/kg of CAPE, anticipate the development of snow showers on Friday afternoon. Dry adiabatic lapse rates extend to 700mb, so a few of these snow showers could produce brief, moderate snowfall with 25-35 mph gusts that could cause brief drops in visibilities.

Well, there's always the NNE thread. It will probably start hoppin’ if there’s significant upslope potential.

Happy to help; just holding down the fort alone while you’re out of town. Hopefully they can get folks that are having difficulty cleared out of the notch before too long. You can see that there’s certainly more upstream moisture that could push into the area this afternoon, and it wouldn’t be surprising to see the elevations pick up some additional accumulation:

I bet a lot of the valleys around here are getting their first accumulations of the season today. It sounds like we’ll be in the flow for much of the afternoon/evening, so there should be continuing chances for rain/snow until some weak high pressure builds in overnight: Area Forecast Discussion National Weather Service Burlington VT 1204 PM EST Sun Nov 3 2019 .NEAR TERM /THROUGH MONDAY/... With the mid-level trough passage, weak high pressure builds ewd across the North Country tonight with chances for rain/snow showers diminishing below 10% early. Will see some breaks in the clouds overnight, but prevailing WSWLY flow will maintain some stratus at times. I just checked the gauge and thus far we’re at 0.2” snow/0.06” liquid for the event, which I’ve got in my records as “Weak mid-level trough moving in from Great Lakes bringing lake-effect moisture on WSW flow”. It’s starting to feel much more like one of those cold season days with the mountains grabbing moisture in the flow - we’ll get a bit of sun and it will seem like things are tapering down, and then it will quickly cloud up and start pouring mixed precipitation with a change in wind.

I thought today was just going to be a bit cloudier version of yesterday, but to that I can give a definite “nope”. This morning I’d raked a few remaining leaves into some small piles that I was going to collect later today, but about 15 minutes ago the wind picked up to the point that it was starting to scatter them. I quick ran around and collected the piles, but of course with the wind came a bout of heavy mixed precipitation that got everything soaked pretty quickly and brought another round of transient accumulation: If we’re getting into the frozen precipitation down here, I figured the elevations had to be getting hit even harder, and indeed I checked the Bolton Valley Live Web Cam at ~2,100’ and there were flakes flying and a coating of white: With bouts like this happening we’ve definitely turned a bit of a corner in the weather here as we’ve move into November relative to the past month or two.

October Precipitation: 6.08” 2019 Precipitation: 52.47” I meant to post the October monthly precipitation a couple days ago, but I’m getting a chance to catch up on it now. October is our second wettest month here behind June, but this one was even a bit above the October average. Moving on to November, it’s typically one of our drier months, but it’s off to quite a roaring start with that event we had a couple days ago bringing almost 3 inches of liquid.

Yeah, absolutely. It’s funny, I’ve got that same excitement for Diane that I have for when an avid skier from the big city finally makes that decision to move out west or up here to live at a resort. Of course, the thing is, she essentially is living at a ski resort. Transitioning up from the south after the way the past several months have been down there has got to be one of the more dramatic examples though. With the elevation they’ve got there, it would be surprising if they don’t see some sort of snow this week.

I’d been occasionally looking outside to see if there was any precipitation this morning, since with that flow off the lakes and temperatures around the freezing mark, it felt like we’d have our first chance at something frozen down here in the valley. And indeed at around 8:00 A.M. we got a graupel shower with a pulse of moisture pushing through the spine: As is often the case with the density of graupel, it quickly accumulated to bring the first measurable of the winter season. We’re actually past the mean dates of first frozen trace (10/20 ± 6 days) and first accumulation (10/26 ± 11 days), but this event is falling well within the 1 S.D. range of the latter, so we’re on track in that regard. The next benchmark I have in my records is the first event of ≥1”, which is (11/8 ± 16 days). There’s quite the variability with the date of that first 1” event, spanning from late October well into November, but we’re certainly in a pattern where we’ll be having some snow chances. At mass this morning my wife was talking with some friends who live up on Blush Hill and they’d already been out earlier making snow angels in their dusting. Oh those NNE snow sickos!

I just looked out my window here in BTV and there’s obvious snowfall crashing out along the western slopes – radar is showing it as well along the spine.

Doesn’t the pattern look fairly zonal though? That won’t necessarily get snow going in October, but once you get into November, a zonal flow is typically going to feature at least some snow at NNE high elevations. There’s snow in the forecast for Mansfield for 3 out of the next 6 days, so it doesn’t really seem that unusual. We’ve even got flakes in our valley forecast over the weekend. Typically we have to have those obvious bouts of below average temperatures to get shots of snow in October, and temperatures have been fairly steady and around average, so we only had that one round of snow earlier in the month. Overall it seems fairly routine for this time of year I guess.

Oh man, if she's going to be in the Alex/Bretton Woods area that's going to be an awesome addition to the upslope zone reports. Actually, unless she's lived in some really special places before, it could be the snowiest place she’s ever lived.

Wow, that’s so cool! Post lots of observations - I hear NNE gets a lot of snow!

October may be getting a bit too much credit by association with the amazing November; the notable tie in was that bit of snow we got at the very tail end (last couple days) of the month that carried over into the first part of November. And, looking at the stake data, the snow depth did briefly go back to zero on November 7th, so it’s not even one of those seasons where the “official” Mansfield snowpack started in October (although it’s possible there were still traces around during that snowpack nadir). The Northern Greens had six accumulating storms last October, which I’m sure is above average in number and indeed notable, but none of them were actually that significant locally. I got out for just one day of skiing that month, and it was a fun low-angle tour, but conditions were pretty marginal compared to what we’ve had during many other Octobers. Here’s a quote from my final report for last October: “We’ve had numerous rounds of snow in the mountains over the past couple of weeks, but none of the storms have been the type that really put down a big dump of 6 to 12 inches or more at once.” I’d certainly categorize last October as “good”, but I’d say it’s hard categorize any of it as epic without at least one of those beefier storms. Of course, a couplet of a decent October and an absolutely outstanding November is a great way to start off the first couple months of the ski season.

Ahh, understood. Indeed that’s true, a lot of those early accumulations seem to come from some sort of terrain assist where all it takes is a bit of moisture in the flow accompanied by marginal temperatures.

Measurable snow by then shouldn’t be remotely surprising for the mountain valleys around here. Mean (as well as median) date for first measurable at our site is 10/20 ± 11 days, so the 11/8 would be well past 1 S.D. and actually closer to 2 S.D. Not that we couldn’t get measurable snow before that, but 11/8 for first accumulation would be in the bottom 4 to 5% of seasons based on the data set thus far.

Relative to averages, it’s been a bit of a slow start to the snow in my area since we’re already past the mean dates of first frozen trace (10/20) and first accumulating snowfall (10/26), but October can of course be quite the wild card in the snowfall area. Unless the models are totally off their rockers though, that first week of November would offer multiple chances for snow with the combination of temperatures, flow off the lakes, and minor disturbances. Even at our place down in the valley we average more than a foot of snow in November, but the S.D. is high, and snowfall can be very lean in certain patterns, so it’s still tenuous. Snow chances showing up in the models inside of a week now is a good sign though, and it’s not the sort of stuff that’s dependent on some big storm forming, it’s just part of the expected flow and minor ripples. Those setups can be pretty reliable for some flakes at longer lead times, but we’ll still want to see that the models hold onto that general scheme over the next few days. With no imminent chances, I’ve been holding off on getting all the snow measurement stuff set up for the winter, but this is probably the week to get moving on it.

It won’t be long now, but can we get things rolling like last November?

Interesting question for some places, but if you were to transform that question into the equivalent for up here in ski county, I bet you’d get very few to vote for that first option. Full blown feast or famine is really not a good way to run a ski season.

It’s a subjective thing as far as I can tell, so I really don’t have any idea. I didn’t see anyone immediately jumping in with confirmation though, so presumably it wasn’t.

Was last season a… “ratter” in SNE?