December 16th, 2012 – Waterbury Winter Weather Event Updates



Tuesday, December 11th, 2012



In his early morning WDEV broadcast, Roger Hill actually spoke about the potential for snow from the possible weekend system.  To hear that the ECMWF has gone colder was encouraging, and he said that the GFS was in that camp, but he doesn’t seem sold because the Canadian Model wasn’t with them.  I was surprised to see so much weight given to the Canadian relative to those other two, but perhaps he’s just not sold on those solutions yet.  He did offer that with regard to what he’s seeing now, it would be a 3 to 6-inch sort of deal.  It’s still a good distance out there though and solutions will probably change a lot before we get there.



Wednesday, December 12th, 2012



Well, Roger Hill was cautiously optimistic about the potential for two Nor’easters next week in his morning broadcast – he said it’s certainly still fragile this far out, but there’s definite potential.  He’s also watching the potential for more storms beyond those.



Thursday, December 13th, 2012



Boston-FranconiaUSA-WX, on 13 Dec 2012 - 10:35 AM, said:


It would be good to get this forum conversation going for what is likely to occur region-wide from Sunday the 16th through the holidays. I feel like a lot of my over/underreaction is based on what largely what the SNE posters are saying when we should be able to better summarize what each model run means for NNE on this board. Anyone with better meteo skills than me want to get us started as to where things stand?


Yeah, the main discussion is very helpful, and I enjoy reading the thoughts, but the general “one-liner” style posts are often heavily weighted toward things going on in the southern part of New England (e.g. latest SREFs look good etc.).  You’re just not as likely to get hour by hour updates on nuances farther north.  That’s not all that different than what goes on up in this forum, as in, I’m not likely to post the winter storm warning maps or excerpts from the forecast discussion from somewhere in Connecticut.  That’s to be expected, but it just means taking some of the comments in the main threads with a grain of salt – at times you actually have to reverse what is said in some of those posts, since what is bad news down there may be good news up here and vice versa.  However, the meteorologists and other professionals often provide much more comprehensive posts that are not as focused on their own back yards, so those can be very helpful to others in the region.  I suspect we’ll start getting some more NNE-focused analysis in this thread as things solidify though; PF and adk will generally provide their thoughts for the mountains, Dendrite will give his thoughts, etc.



Sunday, December 16th, 2012



We saw the first flakes for this event here in Waterbury at 9:57 A.M., just as we were coming out of mass in town, so it looks like the dry weather is over and we’re on to the active pattern.  I saw on the BTV NWS site that we’re under a Winter Weather Advisory, although projected snowfall amounts are certainly more notable off to the east:



It seems like we’re still in that pattern of systems cutting to the west, but even though the systems won’t be all snow, I have to think the mountains are going to put some liquid equivalent into the base – the Mt. Mansfield forecast shows lots of frozen precipitation:



The mountains could definitely use this precipitation though – the snow depth at the Mt. Mansfield Stake is currently at 6 inches, and the mean for this date based on the SkiVT-L Mt. Mansfield Snow Depth Graph looks to be around 26 inches, so it is extremely low.  We’re also past the mean date when the first off piste skiing forays would be taking place based on my calculations using stake data.


On a similar note, I did a mid month assessment of snowfall here at the house, and 2012-2013 is now the least snowy winter through this point since I started collecting data here.  It’s even fallen below the slow-starting 2006-2007, and it’s now well outside the 1 S.D. mark; it’s actually 1.27 S.D. below the mean.  The updated mid month plot is below:



Snow is accumulating outside right now though, so we’ll have to see where this week takes the snowfall stats.



J.Spin, on 16 Dec 2012 - 12:17 PM, said:


Snow is accumulating outside right now though, so we’ll have to see where this week takes the snowfall stats.


I checked outside and as of 11:20 A.M. the snow was closing in on 0.3” of accumulation, so it’s definitely reached the 0.1” mark and will be going into the books.  It’s actually only been a week since the last storm with accumulation, but this week’s dry stretch felt surprisingly long for some reason.



Event totals: 0.4” Snow/0.02” L.E.


I ran a set of noontime observations, and the data are below.  I called the precipitation light snow based on visibility, which is at least a half mile, but at times the snowfall picks up and seems to accumulate rather quickly.


Details from the 12:00 P.M. Waterbury observations:


New Snow: 0.4 inches

New Liquid: 0.02 inches

Snow/Water Ratio: 20.0

Snow Density: 5.0% H2O

Temperature: 26.6 F

Sky: Light Snow (1-3 mm flakes)

Snow at the stake: <0.5 inches



powderfreak, on 16 Dec 2012 - 1:11 PM, said:


Quick half inch at 1,550ft on Mansfield as of 12pm. Snowing a steady light snow.


We’re in a bit of a lull right now with lighter snow, but it looks like there’s a nice slug of snowfall building off to the southwest on the Intellicast Radar:




Between 12:00 P.M. and 2:30 P.M. we’ve picked up another 0.4” of snow, so it’s been falling in the 0.1-0.2”/hr range.



powderfreak, on 16 Dec 2012 - 3:37 PM, said:


Man this is going to be close... especially at elevation.


Whoa that’s tight, but remember… it’s the Northern Greens we’re talking about.


Snowfall intensity has picked up a lot here now, going from that ½ mile visibility to more like ¼ mile visibility.  I can see a band that moved through our area at the I-89/Chittenden County/Washington County junction – flakes are bigger now as well, with numerous ½” to 1” flakes in there, so accumulation should bump up a bit.  You should be getting that in the Stowe area soon:




Well, that was indeed a good burst of snow, the snowboard went from 0.4” to 0.9” in depth in the 2:30 P.M. to 3:00 P.M. block, so the snow averaged 1”/hr during that time.  With regard to my earlier plot of season snowfall, we’re actually close to moving back ahead of 2006-2007 snowfall through this point in the season.  Another round or two of snowfall like that and we’d be there.



Event totals: 1.5” Snow/0.11” L.E.


We headed to a Christmas party in Williston earlier today, and indeed as Nittany said earlier with regard to the western slope areas we passed through like Bolton, Jonesville, and Richmond, accumulations were down somewhat relative to here along the spine at the house.  Once were up in the higher elevations of Williston out near French Hill though, accumulations were back up, and I don’t think they were too far behind what we’ve got here at the house.  The snow was actually coming down at a good clip while I was making the 6:00 P.M. observations, but the flakes are certainly more compact and granular now than they have been at times, and those brought the density of this last round of snowfall up a bit.  Similar to ctsnowstorm’s comment, this storm finally got us into double digits on snowfall for the season.  There’s another couple of tenths of an inch of accumulation out there now, so in fact this event has now allowed 2012-2013 to catch up to the 2006-2007 season in snowfall for this date.


Details from the 6:00 P.M. Waterbury observations:


New Snow: 1.1 inches

New Liquid: 0.09 inches

Snow/Water Ratio: 12.2

Snow Density: 8.2% H2O

Temperature: 26.6 F

Sky: Snow (1-2 mm granular flakes)

Snow at the stake: 1.5 inches



Monday, December 17th, 2012



Event totals: 1.9” Snow/0.19” L.E.


I’m up grading exams, so I was able to take midnight observations.  The snow shut off a while ago, and it’s just been cloudy since, but I did see some definite clear grains of sleet falling before it was done, so it’s not surprising that the density of this latest round of accumulation has shot right up to 20% H2O.  There’s some reasonably dense snow down in the yard now, so I’m starting to wonder if this could actually end up as the start of the winter snowpack – it’s on the late side at this point, but not as late as 2006-2007 (Dec 20th) or 2011-2012 (Dec 23rd).  We’ll have to see how much more frozen precipitation falls and how warm it gets going forward to determine if the ground is going to maintain a covering.  There’s more snow/sleet in the forecast right into tomorrow night though, and it looks like another shot of moisture could be heading this way based on the Intellicast Radar:



Details from the 12:00 A.M. Waterbury observations:


New Snow: 0.4 inches

New Liquid: 0.08 inches

Snow/Water Ratio: 5.0

Snow Density: 20.0% H2O

Temperature: 29.5 F

Sky: Cloudy

Snow at the stake: 2.0 inches



Event totals: 4.8” Snow/0.41” L.E.


The last thing I knew last night was that I heard some ticks of sleet on the windows around 2:00 A.M. as that next push of moisture off to our southwest came into the area.  I’d expected a small dense accumulation on the snowboard this morning, so I was very surprised when I saw a fluffy looking stack of about 3 inches sitting there.  Apparently snow mixed back in and took over, so things look quite wintry out there with 4-5 inches of snow in the yard.  Light snow is still falling, although it looks like there could be a break for a bit before another shot of precipitation moves in.


Details from the 6:00 A.M. Waterbury observations:


New Snow: 2.9 inches

New Liquid: 0.22 inches

Snow/Water Ratio: 13.2

Snow Density: 7.6% H2O

Temperature: 29.7 F

Sky: Light Snow (1-3 mm flakes)

Snow at the stake: 4.0 inches



Event totals: 5.3” Snow/0.45” L.E.


I’m not sure how much additional precipitation to expect from this storm before we move on to the next one, so the above numbers may represent the totals for this event.  In any case, this was a decent storm (largest of the season here thus far in terms of snowfall) that actually pushed season accumulations ahead of 2006-2007 on this date.  So, 2012-2013 isn’t currently bringing up the rear in my snowfall data and it has also moved back to within 1 S.D. (-0.96) of average snowfall.


Details from the 12:00 P.M. Waterbury observations:


New Snow: 0.5 inches

New Liquid: 0.04 inches

Snow/Water Ratio: 12.5

Snow Density: 8.0% H2O

Temperature: 33.6 F

Sky: Light Mist

Snow at the stake: 4.0 inches



powderfreak, on 17 Dec 2012 - 2:00 PM, said:


Nice 5.3" total with a 4" depth. I admire your ability to clear every 6 hours (this event gave you 4 samples right?)...I've got around 4" on the ground and a storm total of 4". (no clearing).

Makes me wonder if in fact that 4" is close to your 5.3" as we both ended with the same amount on the ground. I was looking at CoCoRAHS this morning and you could tell who clears and who doesn't by the difference in snowfall vs depth. The Stowe Village guy had 3.5" of snow at 7am but also a depth of 3.5" so I'm assuming he just measures what's on the ground. There was two spots with 4.8" and 5.0" of snow but depths of 4" in Waterbury.

It makes me wonder if there was a 1.5" difference in snowfall or if it was only a half inch based on snow depth with another inch due to different measuring technique.


This event would definitely come in lower if you measured it all on one fell swoop – especially with some granular flakes and some sleet pellets that fell on top of previous snow.  The snow depth would have been in the 4 to 4.5-inch range if I simply did one check this morning.  Six-hour intervals make a nice routine, and I’d like to do it all the time for consistency (well, probably not the overnight ones), but I’m typically on a 12-hour collection cycle (6:00 A.M. and 6:00 P.M.) on weekdays due to work and sleep.  That’s usually pretty good though, and if the storm is big enough, cancellations and delays help to open up schedules for getting toward the 6-hour cycle – and bigger events provide a little more inspiration for potentially catching that overnight snowboard clearing.  For this event I just happened to be grading exams late into the night last night, so being up, there was no way I was going to skip the midnight collection with the unsure nature of what was going to be coming in the morning.  I’ve also been home this morning doing the same thing, so it let me get in a noontime collection.  Doing the intermediate collections is certainly going to bias accumulations high relative to once a day collection places, but fortunately as adk has indicated in the past, the liquid equivalent is the big equalizer anyway – that’s independent of fluff factor and collection frequency.  I really like getting all these intermediate snow densities through the storm though, you can really get a sense for what is going into the various layers in the snowpack.



powderfreak, on 17 Dec 2012 - 8:02 PM, said:


Must be downslope warming on SSE flow on the western slopes of the Greens... the west side of the spine is one of the warmest spots in New England right now. Pretty cool how topography and wind flow really dictates the weather here in NNE. However, those same warm spots right now stand to clean up this weekend with the potential ULL and upslope combo.


I did head to campus for a few hours this afternoon, so I can pass along some interesting observations from the west slope that you would appreciate.  If you head just a few miles west of here, the depth of snow on the ground drops off very quickly – there’s only about an inch down in the town at BoltonJonesville, Richmond, and even Williston along the highway have basically a dusting on the ground, but surprisingly, at UVM there’s a similar amount of snow to the Bolton area.  Perhaps the downsloping got involved in that distribution.  Also, once I was west of the Greens, the temperatures were up around 40 F this afternoon, so I’m sure that areas with minimal accumulations were already losing them to some degree.




Click the logo to return