NNE Autumn 2013 Thread

[Lava Rock]

looks ominous out there. temp dropping quick. seems like we could see a flake or two.

[hvysnow79]

Lebanon Airport reporting -RA and 41F, but across town here at the hospital it is def all snow and sticking.  Not sure if it just the ASOS or it's actually raining over there, I believe we are about the same elevation.

[MainePhotog]

Some wet flakes and graupel observed at noon in the west end of Portland.

[dendrite]

Some -SHSN at home.

[Ginx snewx]

Some -SHSN at home.

congrats Dendrite

[J.Spin]

A few stray weenie flakes now flying in Winooski but they are few and far between.

 

I saw a similar thing here on the UVM campus around midday today, and even though it was just a few stray flakes, it’s the first time this season I’ve seen them this close to downtown Burlington.  That’s a sign that the atmosphere is primed for some snow.  The wall of white precipitation has been on and off in front of the Northern and Central Greens at various times today, but Mt. Mansfield has clearly been ruling the roost in that regard, standing head and shoulders above all the other peaks with regard to how much snow is being wrung out.  Mansfield has spent much more time invisible than visible this afternoon.

[powderfreak]

I saw a similar thing here on the UVM campus around midday today, and even though it was just a few stray flakes, it’s the first time this season I’ve seen them this close to downtown Burlington.  That’s a sign that the atmosphere is primed for some snow.  The wall of white precipitation has been on and off in front of the Northern and Central Greens at various times today, but Mt. Mansfield has clearly been ruling the roost in that regard, standing head and shoulders above all the other peaks with regard to how much snow is being wrung out.  Mansfield has spent much more time invisible than visible this afternoon.

 

We had some pretty heavy squalls move through... first it was pouring graupel and then it went to your classic huge, upslope flakes.  I was up there for a little over an hour and up to an inch fell during that time at 1,500ft. 

 

 

 

 

 

 

In the background of this shot you can see the VTrans truck closing RT 108 at the Notch...

 

 

 

 

 

 

Lastly, saw my first state plow truck of the season on RT 108.  Snow was only sticking to the road above 1,200ft (Toll House area)... but we've got even a coating of snow down in town on mulch and colder surfaces.

 

[eyewall]

Very nice! I took a trip up the Bolton Road where a decent squall started with gusts of 40 mph or so at 2,000 ft. It quickly whitened the ground, and then was followed by lighter but steady snow. I would say visibility briefly dropped below 1/2 mile (but that is a rough estimate). My car had 28F there. It was clear from about 1,500 ft. up the difference in flakes from the graupel near the bottom. These are some pics I shot.

 

 

[bobbutts]

Had a really brief burst (like 30 seconds) of almost legit snow about an hour ago.  The kind where it's snowing in the back yard, but not the front.

[powderfreak]

It's pulsed back up....under a mile vis again.

Never gets old watching it snow steadily.

[eyewall]

It's pulsed back up....under a mile vis again.

Never gets old watching it snow steadily.

 

I agree! I wanted to stay up there awhile longer

[powderfreak]

I agree! I wanted to stay up there awhile longer

The classic radar, centered over the Mansfield-Bolton stretch...

[dryslot]

We had some pretty heavy squalls move through... first it was pouring graupel and then it went to your classic huge, upslope flakes.  I was up there for a little over an hour and up to an inch fell during that time at 1,500ft. 

 

 

 

 

 

 

In the background of this shot you can see the VTrans truck closing RT 108 at the Notch...

 

 

 

 

 

 

Lastly, saw my first state plow truck of the season on RT 108.  Snow was only sticking to the road above 1,200ft (Toll House area)... but we've got even a coating of snow down in town on mulch and colder surfaces.

 

 

lol, Those legacy outbacks all like to rust in that same spot behind the rear wheel well

[mahk_webstah]

Some -SHSN at home.

Actually got a mod-heavy one over here for about 5 minutes.  Although it was graupel and then rain showers at CON early this afternoon.  Nothing stuck up here though

[dendrite]

Actually got a mod-heavy one over here for about 5 minutes.  Although it was graupel and then rain showers at CON early this afternoon.  Nothing stuck up here though

7-10 split here with just a few flurries from the Sanbornton SHSN. I was in CON for the rain/graupel/snow too.

35.8

[wxeyeNH]

a quick moderate to heavy snow squall moved through my area dropping my vis to about one quarter of a mile very briefly and whitening the ground.temperature fell down to 33 degrees before the Sun came back out and temperature went back up to 36 degrees

[Lava Rock]

lol, Those legacy outbacks all like to rust in that same spot behind the rear wheel well

My wife's 2002 outback with 230K miles had zero rust. We sold it over the summer and the guy that bought it was impressed. So was I.

[Lava Rock]

damn flakes keep drying up as they move east.

[powderfreak]

Pouring graupel again... I've got 0.2" on the snowboard so far but it's interesting how it accumulates on the mulch and stuff. It like pools together in clumps.

[mahk_webstah]

7-10 split here with just a few flurries from the Sanbornton SHSN. I was in CON for the rain/graupel/snow too.

35.8

It was hard enough for a while for us to look outside and say "wow".  And then it was gone and we were left with the view of Kearsarge with the blue, pink and orange sky around it.  I couldn't tell if they had any accumulation up there at 3000 ft.

[dryslot]

My wife's 2002 outback with 230K miles had zero rust. We sold it over the summer and the guy that bought it was impressed. So was I.

 

That's why the guy was impressed because it had none which is rare......lol, Graupel here earlier around 4 pm and weenie flakes about a half hour ago

[powderfreak]

It was clear from about 1,500 ft. up the difference in flakes from the graupel near the bottom. These are some pics I shot.

So I've got a question to throw out there that I was thinking about today, and can't seem to conceptualize the processes involved.....but why in these events does it seem that the mountain can get good snow growth flakes, but then in the lower elevations, it's graupel?

Is it a function of precip intensity (ie heavier precip has better snow growth and big flakes)? In these events, obviously the most sustained intensity of precip exist over the mountain ridges, so does that play into it? I can't imagine low level temps have anything to do with it because flakes vs graupel should be decided high in the cloud. You can't have flakes fall to 1500ft and have it somehow change to graupel below that, can you? I mean the entire structure of the crystal is changing, and graupel forms from riming and convective processes aloft.

So why is it that lower elevations see graupel at the same time it's snowing classic dendrites at higher elevations?

[dryslot]

Probably it passes thru a warmer layer before it reaches the surface so some melting takes place?

[powderfreak]

Probably it passes thru a warmer layer before it reaches the surface so some melting takes place?

Well the column is below freezing except for maybe the lowest 500ft...but I can't see how a melting snowflake turns into a graupel pellet...unless we are just melting the arms off it and the core of the snowflake is graupel in nature?

I just think they are formed aloft in two different ways, so I can't figure out why elevation at the surface would matter, as sometimes we do get the graupel on the mountain. But these early season events seem more real flakes higher up and GS lower down pretty consistently.

[dryslot]

Well the column is below freezing except for maybe the lowest 500ft...but I can't see how a melting snowflake turns into a graupel pellet...unless we are just melting the arms off it and the core of the snowflake is graupel in nature?

I just think they are formed aloft in two different ways, so I can't figure out why elevation at the surface would matter, as sometimes we do get the graupel on the mountain. But these early season events seem more real flakes higher up and GS lower down pretty consistently.

 

I think it has to do with a water droplet that attaches itself to a snow flake and then freezes changing its shape to something similar to an ice pellet

[powderfreak]

I think it has to do with a water droplet that attaches itself to a snow flake and then freezes changing its shape to something similar to an ice pellet

Ahh interesting. I was never totally clear on the differences in how graupel forms vs hail, but I always thought graupel was just convective in that the ice crystal is rising and riming as it interacts with super-cooled droplets in the cloud. Which is what you said, Dryslot. But maybe it finds a way to rime itself in the lower levels?

Or what may be happening is that over the mountains, the lift is greater and thus that crystal is able to punch up into better snow growth temperatures, while over the valleys the crystals are formed in a less favorable environment and end up being rimed prior to falling? Be interesting to hear a mets take.

[J.Spin]

Event totals: 0.1” Snow/0.02” L.E.

 

All I saw today in Burlington was a few stray flakes, so I was certainly interested in catching up on what was going on at home based on the obvious snow falling in the mountains and the reports I was seeing here in the thread.  Heading east from Burlington, flakes began to fall as we got deep enough into the mountains, and once I got into Waterbury it was obviously a different scene from the Champlain Valley – the roads here in town were wet from the precipitation, and I found a crusty accumulation of ice and snow on my car at the Waterbury Park and Ride.  It was definitely nice to see the mountains doing their thing.  Light snow was falling at that point, generally as a mixture of small flakes and graupel, and at 5:00 P.M. I found a sloppy, partially frozen accumulation on the snowboard.  It was a dense accumulation, and more than enough to call for the first core sample of the season.  The tenth of an inch of snow contained 0.01” of liquid.  The precipitation began to pick up toward 5:30 P.M., and when I ran into town to pick up some pie, there were a couple of periods where the snow was falling hard enough that I had to turn down the high beams.  By 6:00 P.M. there were another couple of tenths of an inch on the board that I had cleared an hour earlier.  Anyway, today marks the first accumulations of the month for our location, and getting those first core samples certainly feels like a sign of the season.

 

Details from the 5:00 P.M. Waterbury observations:

 

New Snow: 0.1 inches

New Liquid: 0.01 inches

Snow/Water Ratio: 10.0

Snow Density: 10.0% H2O

Temperature: 36.3 F

Sky: Light Snow (1-3 mm flakes/graupel)

[powderfreak]

Nice, JSpin...finished up with 0.3" here at home which is currently only visible on mulch and dirt surfaces. The graupel just seems to fall through the grass blades and melt...or at least it would take a lot of graupel to cover grass, lol. You really need to get up near Topnotch/Nordic Barn area to see more consistent white on the ground and it looks like there was more like a solid half inch or more accumulating up at that 900ft elevation.

Anyway, second accumulating snow here...though the mini-event last week also put down 0.3" but that stuck to the grass and was much more visibly white.

[OceanStWx]

So I've got a question to throw out there that I was thinking about today, and can't seem to conceptualize the processes involved.....but why in these events does it seem that the mountain can get good snow growth flakes, but then in the lower elevations, it's graupel?

Is it a function of precip intensity (ie heavier precip has better snow growth and big flakes)? In these events, obviously the most sustained intensity of precip exist over the mountain ridges, so does that play into it? I can't imagine low level temps have anything to do with it because flakes vs graupel should be decided high in the cloud. You can't have flakes fall to 1500ft and have it somehow change to graupel below that, can you? I mean the entire structure of the crystal is changing, and graupel forms from riming and convective processes aloft.

So why is it that lower elevations see graupel at the same time it's snowing classic dendrites at higher elevations?

 

For starters, this is helpful just seeing the preferred crystal type by temperature.

 

 

Since temperatures around the level of lift were generally at the lower end of this spectrum, we were talking a lot of needles and plates today. There are a few studies floating around out there that indicate these are preferred collectors of super-cooled water droplets (that lead to the riming associated with graupel). Though super-cooled water can be found as cold as -40 C, I suspect the "warmer" temps today made them that much more likely in the cloud.

 

As for the difference at the mountains, hard to say with total confidence. Could be a combination of factors, including lift, temps, and just the fact that there is less time spent riming before reaching the ground.

[powderfreak]

Thanks for the response, OceanSt. Those higher temp plate and needles were what was falling when it was snow for the most part...but there were some bursts of larger, easily accumulating flakes at the mountain.

In town, I can definitely say it was a mix of graupel and those plates...which look pretty similar if the graupel is small.