J.Spin

Look at the flow right now, it’s basically perpendicular right into the spine.

I’ve got an update from the Winooski Valley this morning – snow line was around 1,500’, so that’s where it seemed to settle in by the morning hours in that area. I saw a car that I assume came down from Bolton that seemed to have about an inch of snow on it, and their base area webcam at 2,100’ shows that they definitely got a refresher of the previous snow.

Updates on the running accumulation at your snow plot are great – what’s the elevation there again (I know it’s somewhere in the 3,000’ range)? It certainly looks like there will be chances for additions to the November total going forward.

We had 0.42” of liquid with this first system, but I’m seeing higher amounts the farther wester toward the western slopes you go. How much L.E. for the mountain thus far? I’m assuming one had to go up to roughly ridgeline elevation to have it all/nearly all fall as snow?

That looks like the next opportunity – with a lot more potential on the back side vs. this last one. If indeed this current pattern holds for a couple of weeks as I saw mentioned on TWC the other day, you can see how a number of similar events could roll through by the end of the month. Even if you just continue to get 4-6” here, 4-6” there, with a couple systems having a bit more punch, it could bring accumulations in the Northern Greens in the realm of bwt’s comment about that GFS snow map.

We had precipitation linger a little while after that main shield cut off, but it was indeed quite dry on the back side – there just wasn’t much of a hookup with additional moisture as that dry air moved in. Down here at our elevation I could see that we got into the snow, but there was never any accumulation that I could detect. For accumulations in the higher elevations around here I’m seeing ~4” on the Sugarbush 3,900’ webcam, ~2 on the Sugarbush 3,125’ webcam, and at the Bolton Valley 2,100’ webcam it looks like accumulations in the 1-2” range.

We’re already starting to get frozen precipitation down here at 500’, so the snow level is definitely descending now. For accumulations on the Sugarbush cams I’m seeing ~0.5” at 3,125’ and ~3” at 3,900’.

I’m totally on board with your accumulations estimates, but I just don’t know if the snow is going to shut off that fast without any backside lingering like we typically see. It seems like once those initial pulses push through, there’s almost always some snow that hangs around as the back side of the system moves through and some winds shift.

LOL, I didn’t know if you’d be up at the mountain today – but your observations seem to line up right with what was showing up on the Sugarbush Summit Cam. The Bolton summit cam at ~3,100’ has been showing some snow now as well. There are many high elevation options around now to watch that snow level drop in the Northern/Central Greens. Jay Peak needs to get their act together with respect to an upper mountain cam as well; they of course have an amazing spot for monitoring snow in the range.

I don’t know about those lower elevations, but Mansfield hour forecast has it snowing through 1:00 A.M., so I don’t think the snow has to fall in just a few hours. The precipitation has already changed over to snow on the Sugarbush Summit Cam up near 4,000’, so presumably the peaks farther north have changed over as well.

Even if that projected liquid ends up being a bit high, it’s hard to imagine that it’s not going to be a good shot of snow from 3,000’ on up. The Mansfield point forecast has precipitation changing over to snow just a couple of hours from now, the temperatures don’t even go above freezing until midweek, and the next few days suggest plenty of snow chances. It depends on what elevation you’re talking about, but in the region of your upper mountain plot, it sure looks like snow is on the way.

Well, I think most of the discussion ended up being about Northern Greens climo in the end. From what I’ve seen, those maps tend to get a bad rap because they can cover extended periods where accuracy wanes, and they apply a variety of (sometimes-flawed) algorithms in simplistic ways. It seems the even bigger knock against them is that weenie types tend to post them to somehow bring the tiniest pinch of faint reality to their unrealistic, sensationalistic snow dreams. If those maps occasionally happen to approach actual climo and reality, we just roll with it I guess.

The 18Z GFS map below presumably covers the period you’re talking about – it goes through the 28th, which is Sunday of Thanksgiving weekend. That obviously spans a couple weeks out from today, and we know the reliability of models beyond about a week, but whatever happens, that’s simply not very far-fetched for the spine of the Northern Greens in November if one just thinks about average snowfall. If we average ~15” here at our site in November, that means that sites at elevation along the spine around here (such as the upper elevations of Jay Peak and Mansfield) should average ~30” in November. PF may be able to tell you what his 3,000’ plot averages for November, but he may not have solid monthly data if he doesn’t start diligently monitoring until the resort opens. It’s hard to tell exactly how much snowfall the map is suggesting along the spine, but let’s say ~40” based on the coloring. That’s not even LOL-worthy; we’ve had almost that much down at our house just in the last 20 days of November before, so for Jay Peak or Mansfield to pull that off would be a piece of cake. At this point, it’s becoming more and more apparent that this isn’t lining up to be one of those Novembers with wall-to-wall above average temperatures that result in little if any snowfall. So I’d argue that the snowfall projected on the map isn’t really outrageous, but skiing Starr or the Face Chutes would probably be pushing it. It’s November, so there’s really no base in place, and unless we get 40” of absolute cement (not our typical density), that amount of snow isn’t quite going to cut it for that terrain. It’s November, so even if getting 40” for the spine isn’t outrageous, having no melting between snowfalls could be tough to pull off. I don’t know about the rest of the locations on there, but that snowfall depicted along the spine of the Northern Greens in the map could certainly be achieved.

Unfortunately, you can’t get a feeling for what the map suggests in the area where the Winooski Valley passes through the spine, since it’s covered by the I-89 icon. If the accumulation gradient is based simply off elevation, then I guess it would be that base, light blue shading as shown for the Lamoille Valley. It’s always fun to see what happens here though because sometimes we get that orographic enhancement that boosts precipitation rates and lowers snow levels below what they would be without the terrain (as I think you mentioned in a discussion the other day).

I’m sure you’ve seen the BTV NWS AFD, but they have snow getting down to similar levels: Area Forecast Discussion National Weather Service Burlington VT 724 PM EST Thu Nov 11 2021 SHORT TERM /SATURDAY THROUGH SATURDAY NIGHT/... As of 335 PM EST Thursday...main forecast points remain valid from the previous runs. Snow levels will lower into the 1000-1500 range with potential for some accumulating snow. Current estimates favor 1-2 inches of snow for elevations down to around 1200ft with 2-4 inches for higher terrain. Very light slushy accumulations will be possible down to around 800ft during the heaviest precipitation period: 00Z Sun through 06Z Sun. For the Northeast Kingdom, consensus forecast amounts are around 1-3 inches, but there are some scenarios that show up to 5 inches possible. The higher amounts would occur if more convective elements were present along and ahead of the wave which some mesoscale models are beginning to show the potential for or if the deepening of the wave slows its exit somewhat.

I typically find that the models/forecasts up to about a week out are reasonably good for dialing in specific storms/events when we’re in a bread and butter-style pattern and no phasing is required. That’s definitely helpful in planning which days/times to head out for turns, and that’s bona fide utility right there in the models. I’m sure the accuracy for what we’re getting there is well improved from a couple of decades ago, because it’s often very good. Most of the time all I need to do is pop up the GFS MSLP/Precipitation frames on TT, check on what it shows for the next several days, cross check with the BTV NWS forecast discussion, and then watch as the shortwaves roll through as predicted. To me that seems like a real high level of practical utility coming from my tax dollars at work. Beyond that roughly one week timeframe though, I just don’t get the utility in the models. Sure, one can get a sense for patterns that set up “storm chances” or snowy periods, but, without specific dates for storms, or any real certainty that they’re going to happen, what’s the point? Does anyone really change anything in their life based on what the “weeklies” show? Just about all we ever hear about on here is how poorly they perform anyway. So who’s going to modify their schedule or do anything differently based on what these extended models show, when they’re often not correct, and even if they are correct, the information, by necessity, is so vague that it’s not useful for planning anything anyway? I certainly agree with your comment though, and I think the combination of now being far enough along into the mid-month period and the apparent residency time of the upcoming pattern speaks to some potential. We look like we’re entering a pattern beyond Saturday where just about every system has a good shot of bringing some snow to the NNE mountains - even if the systems are not 100% snow (which is essentially the situation all winter long anyway). Dr. Postel this morning on TWC did say that it looks like the upcoming pattern could persist for a couple of weeks, which would get well into the back half of November. Unfortunately, the forecast doesn’t tell me which specific days to plan to ski yet, but perhaps we’re getting to the point where the mountain snowpack will start to build at elevation.

On TWC this morning they were talking about the snow potential around here in the coming days, so I guess it’s getting into that closer range. It looks like there are multiple chances from Saturday night right through Tuesday: Area Forecast Discussion National Weather Service Burlington VT 659 AM EST Thu Nov 11 2021 .SHORT TERM /FRIDAY NIGHT THROUGH SATURDAY NIGHT/... As of 351 AM EST Thursday...Initially southerly 850mb winds of 20 to 30 knots wl result in 850mb temps 0-1C on Saturday aftn, supporting snow level around summit level (4000 ft or higher), but as winds shift to the west/southwest again btwn 00z-03z, slightly cooler air arrives, also helped by evaporational/dynamical cooling. However, progged 925mb temps still stay either side of 0c thru 12z Sunday, resulting in pretty high snow levels thru the event. Crnt thinking shows snow levels dropping to 1200 to 1500 feet by 06z or so, supported by freezing levels near this elevation. As far as accumulations, thinking 2 to 5 inches near summit level with a dusting to 1 inch for 1200 to 1500 level, while 1 to 3 inches is possible acrs the midslope locations. .LONG TERM /SUNDAY THROUGH WEDNESDAY/... As of 351 AM EST Thursday...Have mention chc pops for Sunday night into Tues associated with s/w forcing and enhanced mid lvl moisture, along with developing upslope flow under modest llvl caa. Have focused the highest pops in the upslope regions of the northern Dacks into the mtns of central/northern VT attm with values in the chc range (30 to 50%). We will be watching closely the potential for a stronger system which would produce more widespread precip acrs our cwa. Once again thermal profiles support mainly elevation depend snowfall potential, as progged 925mb temps hover either side of 0C thru 00z Tues, before cooler air arrives with developing northwest flow on Tues.

I think what you saw on Thursday was about it for the last potential shot of that snowfall event – I don’t think there was much of any snow in the lower valleys from that. My students have been telling me about a few folks that got out for turns on the snow from the recent event, but it seemed really marginal/borderline. Apparently, Mansfield saw 6” or so up around 3,000’ based on the reports I heard from you? I’d assume something similar at Bolton, and based on their base area webcam, it looked like maybe 3-4” at 2,000’? The word I heard was that folks were mostly straight lining in the available snow, which is fun for the novelty I guess, but my threshold is typically around 6”+ on low angle, appropriately manicured terrain – something that will let you make some real turns without too much concern. After this pleasant stretch, we’ll potentially start to get into some snow chances again though. There’s a hint of some possible flakes in the higher elevations tonight into tomorrow, and then more potential toward the weekend: Area Forecast Discussion National Weather Service Burlington VT 934 AM EST Tue Nov 9 2021 LONG TERM /THURSDAY THROUGH MONDAY/... As of 257 AM EST Tuesday... A dry slot will quickly wrap in Friday night and steady rainfall will quickly come to an end. The center of the occluded system will become quasi-stationary over western Quebec near James Bay over the weekend, leading to a period of cooler and showery weather for the North Country. These showers will mainly be in the form of rain for valley locations, however some brief light snow showers can`t be ruled out. Higher elevations will see primarily rain showers during the days and some snow showers overnight as temperatures drop to below freezing.

Unfortunately, I think that the timing of your move to your NH place probably just served to enhance that. The two preceding seasons were ridiculously early starts – you can see how much they stand out in the plot below. Think about that – just two seasons ago, the permanent winter snowpack was starting today – even in the lower mountain valleys. That’s a tough start for anyone that didn’t have their winter prep work done by that point. For winter snowpack start dates at our site, the mean is 12/2, and the median is 12/5, so the dates from ’18-‘19 and ’19-‘20 are way ahead of average. Last season’s 12/6 start wasn’t actually all that far off from average, but it was so thin at periods in both mid-December and around Christmas that it ended up feeling like a much later start.

Maybe you’ll have the opportunity to see the tenor of another shot soon. I figured this overall event was generally winding down today, but I saw on the models, most obvious in the mesoscale realm, that there’s another pulse of moisture in play that should be something to watch into tomorrow morning. There’s a ~260° connection off Ontario that’s most obvious on the 3K and 12K NAM. It varies from model to model, but it’s enough to get into the near term BTV NWS AFD: Area Forecast Discussion National Weather Service Burlington VT 735 AM EDT Thu Nov 4 2021 NEAR TERM /THROUGH FRIDAY/... As of 735 AM EDT Thursday...another round of lake effect precipitation is expected later this afternoon as an upper level disturbance moves through. Not anticipating as widespread areal coverage as yesterday, nor as intense showers, given weaker instability and lack of unidirectional wind shear....regardless though a few scattered rain/snow showers mainly for the Adirondacks and into the northern VT area expected this afternoon/evening. Light snow accumulations are likely over the higher terrain (less than one inch) with mainly rain or trace amounts of snow for the valleys. Temps will continue below normal across the area today with highs in the low to mid 40s.

I guess this is one where we have both the lakes and the mountains to thank for that classic 255-260° hookup that was rolling initially, and of course there was some WNW flow later as well. The minor waves/disturbances did their part too, but the whole thing probably wouldn’t have amounted to a hill of beans were it not for the lakes and mountains. I haven’t quite found an image for that hookup yet, but I did find one to give the spine some props.

Great stuff PF; love those BTV mets!

Event totals: 0.3” Snow/0.28” L.E. After just 0.02” of liquid in the gauge this morning at observations time, today’s snow brought another 0.26” to add some oomph to this event. We certainly got some good whitening of the area this afternoon, but accumulations were transient down at our elevation and 0.2” is the most I saw here at our site. The precipitation did start out as some rain and mix this morning before changing over to all snow, but I don’t really have a split on the bit of precipitation on the front end that might have been rain, so I’m just rolling all the L.E. into the snow. Details from the 8:00 P.M. Waterbury observations: New Snow: 0.2 inches New Liquid: 0.26 inches Snow/Water Ratio: 0.8 Snow Density: 130.0% H2O Temperature: 34.3 F Sky: Flurries Snow at the stake: 0”

Thanks wxeye, I was just about to enter today’s accumulations. It looks like Kevin will just have to add a 2021-2022 option to that pull down menu for season and we’ll be good to go? Hopefully it’s that easy for him now with the updated system.

BTV NWS had a noontime update on today’s snow: Area Forecast Discussion National Weather Service Burlington VT 1159 AM EDT Wed Nov 3 2021 .NEAR TERM /THROUGH THURSDAY/... As of 1157 AM EDT Wednesday...Tweaked the forecast a bit early for the area of snow traversing the Champlain Valley now. On the northern slopes of the Dacks, we`ve been receiving reports of measurable snow, and Plattsburgh, NY is reporting a mile and a half visibility with the snow at this time. Increased PoPs higher again, and lowered forecast high temperatures as wet-bulb cooling keeps us from warming too much. The rest of the forecast is on track. Have a great day!