Memorial Day Weekend Coastal/Snow

[Ginx snewx]

MWN 23 N 89 G 101

[N. OF PIKE]

Vermont is the 3rd least population dense state in the country. If ur saying ne vermont is rural for vermont, then i guess nobody really lives there lol. It does seem like most of ne vt got 3-4 inches thou .

[CoastalWx]

It really doesn't matter at all at this point, haha so I shouldn't be arguing...the population above 1500ft though is quite sparse in an already extremely rural part of Vermont. That's the part of VT people picture in their minds when they think of "rural" backwoods.

I think it just goes to show that the ern areas got hit a bit harder and the wrn areas a bit less than we (well me in this case) thought. I may be wrong, but sounds like wrn areas closer to BTV have more population.

But regardless...an awesome event and long live winter.

[joey2002]

But regardless...an awesome event and long live winter.

 

Deep, deep winter.

[MarkO]

There are 3 winter scenarios that , for lack of a better word "excite" me. One is epic as in '78, second is over performer, which is fortunately more common than the others, and the third is the unusual which I experienced this weekend. I probably embarrassed my wife and kids but I have no regrets. It was awesome. Woty worthy post, that's fine.

[N. OF PIKE]

In my dreams, i would have a cabin @3500 in northern greens. I would have nadia g as my personal chef , and i would invite all fellow weenies up in snow events. There prob is some sort of zoning law against building above 2.5k, but i guess 2490' would do.

[J.Spin]

Nice J.Spin!

Was that 22" in a drift or a more even snow measurement? I just find the COOP's 13-14" hard to believe with over 3" of liquid. 22" settled snow depth makes more sense.

 

That 13-14” (snow depth I presume) from the COOP would actually fit reasonably well with my observations, since the COOP is over by The Nose.  I measured a consistent 10” with areas of 12”-15” at 3,300’ below The Nose, so that’s pretty similar to the COOP observations, although they could be a bit higher with that extra elevation.  For whatever reason, the high-elevation snow was just notably deeper with this storm over by the Gondola.  I know that area is below The Chin and often pulls in the most snow, but the difference seemed quite extreme with this storm.  Perhaps this wind flow pattern really favored The Chin area for some reason.  That 22” measurement wasn’t a drift as far as I could tell – it was right out in the middle of Perry Merrill, probably a couple dozen yards south of the Cliff House.  I probed around there in numerous spots and got a lot of 22” and 23” readings.  The snow was flat all around the trail there and there was no obvious drifting, which is why I wrote in my full report about it being deceptive – you really wouldn’t have known that there was so much snow underneath you unless you probed it with a measurement device.  I’d be curious to find out how quickly the snow increased in depth above that elevation, because it started to drop off very quickly below the Cliff House, down to the 12”-15” range in just a few hundred feet of elevation.  It was so dense though that it covered everything with room to spare – as you can see from that Perry Merrill shot.

[powderfreak]

I think it just goes to show that the ern areas got hit a bit harder and the wrn areas a bit less than we (well me in this case) thought. I may be wrong, but sounds like wrn areas closer to BTV have more population.

But regardless...an awesome event and long live winter.

 

Yeah, me too.  I never would've put the jackpot for inhabited areas in eastern VT.  I still was thinking western slope communities (which are basically Burlington suburbs) with locally lower snow levels and enhanced precip but those NW winds never really materialized during the meat of the event.  That's exactly what happened in the April 25-26, 2010 event, with surprisingly low snow levels and accumulations in excess of 18" in relatively populated areas.

 

Apparently the drifts on the mountain were impressive... I've seen some big drifts but I can tell you by the size of this one on Nosedive (based on my experience on the mountain) that this was a solid snowfall of in excess of 12"...probably more like 18".

 

 

Down lower though, the pics just look bizarre with all the green around...heck you can see the golf course down in the base area and its been open for a couple weeks now.

 

[powderfreak]

That 13-14” (snow depth I presume) from the COOP would actually fit reasonably well with my observations, since the COOP is over by The Nose.  I measured a consistent 10” with areas of 12”-15” at 3,300’ below The Nose, so that’s pretty similar to the COOP observations, although they could be a bit higher with that extra elevation.  For whatever reason, the high-elevation snow was just notably deeper with this storm over by the Gondola.  I know that area is below The Chin and often pulls in the most snow, but the difference seemed quite extreme with this storm.  Perhaps this wind flow pattern really favored The Chin area for some reason.  That 22” measurement wasn’t a drift as far as I could tell – it was right out in the middle of Perry Merrill, probably a couple dozen yards south of the Cliff House.  I probed around there in numerous spots and got a lot of 22” and 23” readings.  The snow was flat all around the trail there and there was no obvious drifting, which is why I wrote in my full report about it being deceptive – you really wouldn’t have known that there was so much snow underneath you unless you probed it with a measurement device.  I’d be curious to find out how quickly the snow increased in depth above that elevation, because it started to drop off very quickly below the Cliff House, down to the 12”-15” range in just a few hundred feet of elevation.  It was so dense though that it covered everything with room to spare – as you can see from that Perry Merrill shot.

 

Cool, great information.

 

The Co-Op though never reported a snow depth at the stake of greater than 6", which I find interesting/hard to believe.  The 4pm depths were 4" yesterday and 6" today.  I find it hard to believe there was only 6" on the ground even this afternoon at the 3,800ft stake.

 

DAILY HYDROMETEOROLOGICAL DATA

NATIONAL WEATHER SERVICE BURLINGTON VT

542 PM EDT SAT MAY 25 2013

STATION PRECIP TEMPERATURE PRESENT SNOW

24 HRS MAX MIN CUR WEATHER NEW TOTAL SWE

...VERMONT...

MOUNT MANSFIELD 1.60 34 27 27 MDT SNOW 7.5 4

 

 

DAILY HYDROMETEOROLOGICAL DATA

NATIONAL WEATHER SERVICE BURLINGTON VT

726 PM EDT SUN MAY 26 2013

STATION PRECIP TEMPERATURE PRESENT SNOW

24 HRS MAX MIN CUR WEATHER NEW TOTAL SWE

...VERMONT...

MOUNT MANSFIELD 1.69 31 26 31 5.7 6

[joey2002]

Awesome photos J.Spin and powderfreak! 

 

Down to 39 degrees already... I think frosty will pay us a visit tonight. 

[ORH_wxman]

Well back from VT....a bit dissapointing right near where I was as the NW flow never got established as fast as model guidance said it would. I think a couple things happened...first, the low stalled a bit more to the SW for longer than modeled which kept the BL winds more northerly for longer...and two, the deformation/CCB wrapped pretty far west which cost us probably a bit of adidtional cooling.

 

 

The funny part was I saw snow at around 1700 feet near Barre VT on early Sunday morning but didn't see it up by Stow/Bolton Valley until over 2k. The eastern areas def did better. I also was able to skim some of the thread I missed and saw that NH over-achieved in the snow department. Definitely an interesting system and pretty wild for Memorial Day weekend. I was hoping to see a bigger snow, but seeing any at all below 2k was pretty cool.

 

Now that tracking that system is over with winter's one last hurrah...it almost feels like its time to pack it in for the summer. Any weather now over the next 6-8 weeks would seem much less interesting unless it was a legit high end severe threat.

[CoastalWx]

Well back from VT....a bit dissapointing right near where I was as the NW flow never got established as fast as model guidance said it would. I think a couple things happened...first, the low stalled a bit more to the SW for longer than modeled which kept the BL winds more northerly for longer...and two, the deformation/CCB wrapped pretty far west which cost us probably a bit of adidtional cooling.

 

 

The funny part was I saw snow at around 1700 feet near Barre VT on early Sunday morning but didn't see it up by Stow/Bolton Valley until over 2k. The eastern areas def did better. I also was able to skim some of the thread I missed and saw that NH over-achieved in the snow department. Definitely an interesting system and pretty wild for Memorial Day weekend. I was hoping to see a bigger snow, but seeing any at all below 2k was pretty cool.

 

Now that tracking that system is over with winter's one last hurrah...it almost feels like its time to pack it in for the summer. Any weather now over the next 6-8 weeks would seem much less interesting unless it was a legit high end severe threat.

 

Yeah models were hinting at that band moving towards the Dacks...but like you..I was hoping the upslope would offset that a bit...but alas winds were a little too northerly.

 

Funny how areas further east did much better...almost what I was hoping to see for places like Stowe etc. Coles Pond got crushed...still snow OTG. Dendrite got almost a half inch which is just amazing. Places near Franconua Notch got 4+". TSSN also for Wxeye.

[Logan11]

I think the whole scenario about six-eight weeks ago would have meant a crushing for this area. It was the best positioned coastal storm of the season for ENY ironically.

 

 

Yeah models were hinting at that band moving towards the Dacks...but like you..I was hoping the upslope would offset that a bit...but alas winds were a little too northerly.

 

Funny how areas further east did much better...almost what I was hoping to see for places like Stowe etc. Coles Pond got crushed...still snow OTG. Dendrite got almost a half inch which is just amazing. Places near Franconua Notch got 4+". TSSN also for Wxeye.

[ORH_wxman]

Yeah models were hinting at that band moving towards the Dacks...but like you..I was hoping the upslope would offset that a bit...but alas winds were a little too northerly.

 

Funny how areas further east did much better...almost what I was hoping to see for places like Stowe etc. Coles Pond got crushed...still snow OTG. Dendrite got almost a half inch which is just amazing. Places near Franconua Notch got 4+". TSSN also for Wxeye.

 

 

Yeah I also think 5H deepened more rapidly than modeled which really tucked that low S or SW of PWM...I think that also helped out NH get more dynamical snows.

 

 

Either way it was just an incredibly dynamic event for that late in the season...even if you eliminate the snow aspect...seeing that type of conveyorbelt and thermal gradient in a late May coastal is amazing. I am trying to catch up a bit in that other thread, but that's cool how well NH did. I'm wondering if ORH ever got flakes mixed in...I saw temps got to 36F with rain so it definitely might have mixed. ASOS often has trouble picking up on the R/S mix.

[powderfreak]

Yeah I also think 5H deepened more rapidly than modeled which really tucked that low S or SW of PWM...I think that also helped out NH get more dynamical snows.

Either way it was just an incredibly dynamic event for that late in the season...even if you eliminate the snow aspect...seeing that type of conveyorbelt and thermal gradient in a late May coastal is amazing. I am trying to catch up a bit in that other thread, but that's cool how well NH did. I'm wondering if ORH ever got flakes mixed in...I saw temps got to 36F with rain so it definitely might have mixed. ASOS often has trouble picking up on the R/S mix.

The lesson learned is the climo favored location of stacked lows is closer to FVE not BOS/PWM vicinity....at least for NW flow upslope in the northern Greens. There was actually a decent little upslope response yesterday afternoon/evening once the low got far enough north.

[ORH_wxman]

The lesson learned is the climo favored location of stacked lows is closer to FVE not BOS/PWM vicinity....at least for NW flow upslope in the northern Greens. There was actually a decent little upslope response yesterday afternoon/evening once the low got far enough north.

 

 

Yeah I suppose that was a model error that might have been predictable....but the models did have solid NW flow much earlier than actually happened which is one reason I was more excited. They had the low trying to stretch NE and the 5h low was trying to tug is back SW...the latter obviously was more dominant. I remember model guidance showing pretty solid NW flow up to about 900-925mb which should be great for smashing into that 3000-4000 face.

 

 

I think the CCB/deformation getting pushed pretty far west was a sign in retrospect as well they everything was a bit deeper and further SW than originally modeled. IT ended up helping out NH and NE VT but hurting W slopes.

[nzucker]

Yeah I also think 5H deepened more rapidly than modeled which really tucked that low S or SW of PWM...I think that also helped out NH get more dynamical snows.

 

 

Either way it was just an incredibly dynamic event for that late in the season...even if you eliminate the snow aspect...seeing that type of conveyorbelt and thermal gradient in a late May coastal is amazing. I am trying to catch up a bit in that other thread, but that's cool how well NH did. I'm wondering if ORH ever got flakes mixed in...I saw temps got to 36F with rain so it definitely might have mixed. ASOS often has trouble picking up on the R/S mix.

It was an amazing event. Even around here, some people reported sleet or graupel mixing in a bit, not sure I believe that in NYC but who knows...having a high of only 53F is pretty crazy for Memorial Day weekend when we should be well into the 70s. Definitely the latest I've seen a cold system like that. We've had three nights in a row well into the 40s even down here, which is very impressive, and feels great considering what I know is coming. I'm going to enjoy the last cool night tonight produced by the flow behind this system. 

[CoastalWx]

Yeah Will...agree about the models. I thought they would upslope too, but a little too much nrly component. Still, the fact that Marshfield VT at 1600' got 4" at least tells us we were on the right trail...just that the low was a little too far SW for good upslope. 

 

A record event regardless. Onto the doldrums now.

[wxeyeNH]

In this area of Central NH the last visible snow that I could see melted this AM on Mt Cardigan 3120'. Looking to the north today the White Mountains were really beautiful being full green and white at the tops. This afternoon my neighbors yard still had small snow piles from where the snow melted and slid off their metal barn roof.

[powderfreak]

Yeah I suppose that was a model error that might have been predictable....but the models did have solid NW flow much earlier than actually happened which is one reason I was more excited. They had the low trying to stretch NE and the 5h low was trying to tug is back SW...the latter obviously was more dominant. I remember model guidance showing pretty solid NW flow up to about 900-925mb which should be great for smashing into that 3000-4000 face.

 

 

I think the CCB/deformation getting pushed pretty far west was a sign in retrospect as well they everything was a bit deeper and further SW than originally modeled. IT ended up helping out NH and NE VT but hurting W slopes.

 

Yeah 900mb should have done it... but with H85 winds mostly northerly, it still doesn't seem to develop as well.  I really like the H85 winds being NW.  Lower level winds below H85 can even be almost westerly with NW winds at H85, but for whatever reason, those H85 vectors are key, IMO.

 

Anyway, the further SW location of the entire package of low/mid level lows definitely hurt...that deformation zone sat out in the Adirondacks for most of the day, thus the 3 foot snows at 4-5000ft in the eastern Adirondacks (but they upslope on that NE/NNE flow that persisted at H85, too).

 

The northerly flow actually causes the enhancement to be back towards BTV in the precipitation department, which doesn't help because its one of the lowest elevations in VT.... but northerly flow causes a little QPF maximum in the middle of the valley from the convergence, and the more westerly flow causes that enhancement to migrate eastward.  BTV out in the valley ended up with more 24 hour precipitation than both MPV and MVL in the mountains.

 

Still an awesome event and I've seen reports of anywhere from 14-24" on Mansfield, along with J.Spin's 22" depth measurement at 3,600ft...so that's a very sizable snowfall.  Even the 13.2" at the Co-Op is fairly impressive as that is a big snowfall for that station and their method of measuring.  Anything over 10" at that station is a decently large snowfall...(because it usually corresponds to like a 18"+ snowfall in reality down just off the summit). 

[powderfreak]

Some more snowfall pics from around the Stowe/Mansfield region...

 

Not too often people are mowing their lawns in town while the mountain sits blanketed in fresh snow.

 

 

[ORH_wxman]

Yeah 900mb should have done it... but with H85 winds mostly northerly, it still doesn't seem to develop as well.  I really like the H85 winds being NW.  Lower level winds below H85 can even be almost westerly with NW winds at H85, but for whatever reason, those H85 vectors are key, IMO.

 

Anyway, the further SW location of the entire package of low/mid level lows definitely hurt...that deformation zone sat out in the Adirondacks for most of the day, thus the 3 foot snows at 4-5000ft in the eastern Adirondacks (but they upslope on that NE/NNE flow that persisted at H85, too).

 

The northerly flow actually causes the enhancement to be back towards BTV in the precipitation department, which doesn't help because its one of the lowest elevations in VT.... but northerly flow causes a little QPF maximum in the middle of the valley from the convergence, and the more westerly flow causes that enhancement to migrate eastward.  BTV out in the valley ended up with more 24 hour precipitation than both MPV and MVL in the mountains.

 

Still an awesome event and I've seen reports of anywhere from 14-24" on Mansfield, along with J.Spin's 22" depth measurement at 3,600ft...so that's a very sizable snowfall.  Even the 13.2" at the Co-Op is fairly impressive as that is a big snowfall for that station and their method of measuring.  Anything over 10" at that station is a decently large snowfall...(because it usually corresponds to like a 18"+ snowfall in reality down just off the summit). 

 

 

Your mention fo the low needing to be more near N Maine is an interesting benchmark in that it could be a good climo indicator when to sort of "sniff out" some biases in the models that could be red flags. The models did indeed have NW flow by Saturday evening but it really never materialized until Sunday morning/midday. Perhaps the fact that the models were stalling the low closer to PWM could have been a red flag (along with 850 winds being more northerly) as to adjust the modeled BL winds.

 

This could be akin to a situation when we see the models in a CAD situation try to turn the winds at ORH more out of the E or SE but I know immediately to "adjust" the winds at least 30-40 degrees counterclockwise knowing that a sfc low tracking near the Canal with a high poking down from Maine always has winds more NE over Central MA than modeled.

 

Also even aside from the NW flow issue, I think the CCB/deformation initially being pushed W into the Dacks did hurt a little bit too because it lightened the precip intensity and mid-level UVVs downward during a time when we were still trying to cool (and had managed to get the snow level down to 1500 feet by then)...and it actually ended up slightly warming again during that lull in late evening.

 

 

But we saw sort of a second pseudo deformation forced over central NH as the 500mb low nuked out and that's when we saw the accumulating snow get down to like 500 feet there...pretty incredible. So the deeper tucked low at least benefited some other areas. As I mentioned before, I saw snow to the E of Barre, VT on Sunday morning at 1600-1700 feet when I didn't see any up to like 2k at Stowe. Pretty remarkable.

[Ginx snewx]

PF that pic with the plowed fields the green grass and the background of snow is spectacular.

[powderfreak]

PF that pic with the plowed fields the green grass and the background of snow is spectacular.

 

Yeah my friend (former roommate) took that.  Unfortunately I can't take credit for it.  That is the view from the 6 mile paved Stowe Recreation Path.

[powderfreak]

Your mention fo the low needing to be more near N Maine is an interesting benchmark in that it could be a good climo indicator when to sort of "sniff out" some biases in the models that could be red flags. The models did indeed have NW flow by Saturday evening but it really never materialized until Sunday morning/midday. Perhaps the fact that the models were stalling the low closer to PWM could have been a red flag (along with 850 winds being more northerly) as to adjust the modeled BL winds.

 

This could be akin to a situation when we see the models in a CAD situation try to turn the winds at ORH more out of the E or SE but I know immediately to "adjust" the winds at least 30-40 degrees counterclockwise knowing that a sfc low tracking near the Canal with a high poking down from Maine always has winds more NE over Central MA than modeled.

 

 

Speaking of all of this, I opened up one of the original upslope precipitation studies for the Green Mountains and Adirondacks (Bosart, Sisson, St. Jean) and found these nuggets of information that are remarkably similar to this event.

 

They had two events, one (November 1999) produced very significant snowfall in the upslope region...and another event (March 2000) that was forecast to produce heavy upslope snow and failed to do so.

 

The case that failed to produce significant snowfall in March 2000 looks remarkably similar to this past event in terms of where the H5 cut off was as well as the H85 lows.  Both storms had northwesterly flow in the lower levels, but only the storm with northwesterly flow at H85 and H5 produced significant snowfall.  I've always known that the low AND mid level lows need to be near FVE/Northern ME for a true heavy upslope event, but this just drives that point home.  You could draw bullseyes over northern Maine under the H5 and H85 lows in the "heavy snow" case in this study:

 

"Comparisons of the heavy snowfall case (16 November 1999) and the null case (3 March 2000)

yielded some significant differences in the two regimes.  The heavy snowfall case was characterized

by a persistent, strong northwesterly flow at the 500 hPa and 850 hPa levels.  Although both

cases exhibited northwesterly low-level flow (i.e., cross-barrier to the Green Mountains and Adirondack Range)"

 

 

 

[ORH_wxman]

Great stuff PF...maybe we should have looked at this aspect a bit closer before the past event. I figured big deformation with low level NW flow would be great for upslope...but the problem is the low level flow never really backed NW enough until late and the deformation did end up a bit west. I'm looking back at some Euro runs now, and I am noticing a slight shift in the final few runs of the low level winds a bit more northerly than some of the runs a bit before that. Something that probably got overlooked but certainly was important.

 

Perhaps looking at the 850mb flow in these types of setups is better than relying on the modeled BL flow which can be more finicky and subject to model biases. The 850 flow is probably pretty accurately modeled and the 900mb flow is going to be similar to 850 usually.

 

 

I think the climo benchmark of the low being up in N ME proved more accurate than the modeled NW flow in the lower levels. If I had more knowledge on the model biases during upslope events, this is something I probably would have been more concerned about on the western spine.

[Cold Miser]

PF that pic with the plowed fields the green grass and the background of snow is spectacular.

Agree 100%. Almost like something shot in the rockies or Europe. Awesome.

[CoastalWx]

Great stuff PF...maybe we should have looked at this aspect a bit closer before the past event. I figured big deformation with low level NW flow would be great for upslope...but the problem is the low level flow never really backed NW enough until late and the deformation did end up a bit west. I'm looking back at some Euro runs now, and I am noticing a slight shift in the final few runs of the low level winds a bit more northerly than some of the runs a bit before that. Something that probably got overlooked but certainly was important.

Perhaps looking at the 850mb flow in these types of setups is better than relying on the modeled BL flow which can be more finicky and subject to model biases. The 850 flow is probably pretty accurately modeled and the 900mb flow is going to be similar to 850 usually.

I think the climo benchmark of the low being up in N ME proved more accurate than the modeled NW flow in the lower levels. If I had more knowledge on the model biases during upslope events, this is something I probably would have been more concerned about on the western spine.

I actually noticed the winds more nrly on the final

Euro runs when comparing Friday's 12z runs vs Saturday's 12z runs, but the 950 and 925 winds looked like they were still trying to go NW on the models so it was easy to get excited. The models did have the Dryslot moving in, but it looked like upslope flow could save the day. In the end, another lobe rotating in dumped on central NH Saturday night.

[ORH_wxman]

I actually noticed the winds more nrly on the final

Euro runs when comparing Friday's 12z runs vs Saturday's 12z runs, but the 950 and 925 winds looked like they were still trying to go NW on the models so it was easy to get excited. The models did have the Dryslot moving in, but it looked like upslope flow could save the day. In the end, another lobe rotating in dumped on central NH Saturday night.

 

 

Yeah...I think PF's mention of the climo spot for ideal upslope ended up proving more accurate than the models trying to maintain the flow a bit more NW than what actually happened.

 

But while it made the event slightly disappointing in the western spine, it surely was pretty amazing in other spots like NH and even eastern VT...so definitely cannot minimize that aspect.

[HIPPYVALLEY]

The flakes I saw in the wee hours were 8 straight months of seeing snow fall from the sky. I think that's a first for me.