powderfreak

Ahhh ok so it wasn't necessarily a downslope valley event but more a pure elevation event. I usually put downslope in the "it doesn't precipitate much" category while moisture gets wrung out on the slopes. Not sure what anyone classifies that storm as.So massive QPF event with a very tight rain/snow line. Obviously probably some upslope assist in dynamic cooling, and compressional warming on the downside, but I love those tight snow lines. We see those gradients on the mountain but it's much more dramatic when it happens in populated areas so close to the surface. Rain below 2,000ft and 30" of snow at 3,000ft isn't as dramatic as rain at sea level and 30" at 1,000ft. Reminds me of the April 2012 upslope event at Stowe where the office at 1,500ft had 3" of like white water, but it was 18"+ just 500ft higher at 2kft, and 30"+ above 2,500ft. Total QPF was almost 4" at the summit Coop. One of the highest QPF events I've ever seen from orographics. No thermal advection, just a steady state heavy precip event where heavy rates can only bring the snow level down so far.

That thing is still going? Never would've thought.

The Catskills and Helderbergs are underrated for snow as we don't hear much out of those areas, especially with Logan/Rick posting less. They have some huge events and may even be better at E/SE upslope flow than the Berkshires. There are a lot of inhabited towns at 1,500ft+ and even 2,000+ feet. Mountains are 3-4,000ft. They get crushed in a lot of the big synoptic storms, especially prolonged east flow.

What were total QPF amounts? Was it that no precip fell in the valleys or was it rain?I honestly can't really fathom that map. That's more obscene gradients than our upslope precipitation events in the Greens. Would've loved to see a radar loop of that entire storm. Like what would a vertical profile look like to have so much blocked air over the terrain to wring out that much snow, yet be able to downslope the valleys so much. That takes a very special set of circumstances (inversion levels or slight veering winds) more than just saying east flow upslope/downslope.

Yeah the thing with orographics and relatively small uplift (say 1,000ft of terrain change) is that you need to have a way for the air to "pile up" to reap the benefits. With such a small terrain change, it's not hard for air to flow freely over the "barrier." You need to block it up with an inversion and/or veering winds...like you said with a cap around 3,000ft. I would imagine the best effects are with ENE winds at the SFC up to 900mb, but veering SW to SE flow above that...to really get that air to "pile up" on the windward facing slopes. Up here I get screwed on the east side when the veering winds are too low in the atmosphere as its blocked on the west side. I want my inversion more at like 7,000ft...enough to pile up air but also let it get over the 4,000ft spine.

Yeah the thing with orographics and relatively small uplift (say 1,000ft of terrain change) is that you need to have a way for the air to "pile up" to reap the benefits. With such a small terrain change, it's not hard for air to flow freely over the "barrier." You need to block it up with an inversion and/or veering winds...like you said with a cap around 3,000ft. I would imagine the best effects are with ENE winds at the SFC up to 900mb, but veering SW to SE flow above that...to really get that air to "pile up" on the windward facing slopes. Up here I get screwed on the east side when the veering winds are too low in the atmosphere as its blocked on the west side. I want my inversion and wind shift more at like 7,000ft...enough to pile up air but also let it get over the 4,000ft spine. Often in a deep layer uniform flow the orographic effects are much less....I'm not sure what the profile looked like for March 2013 storm, but that set up didn't scream orographics to me. More like deep layer firehose and synoptic screw zones, not upslope/downslope.

Yeah you want that look of what is going on from ORH northward...uniform topographic rises that can force a whole bunch of air up and over. The barrier needs to be sufficiently long to stop air from just going around the barrier, too.Looking at where he is, on a more isolated bump at the edge of the chain, there's really nothing there that would indicate even on a southerly/SE/SW flow it would make much difference. There's still not a "wall" big enough to do anything appreciable in enhancing QPF in any way. You can see the "purple" areas on that map are probably the spots where any enhancement occurs.

This is what upslope looks like on a seasonal scale. Just look at Washington County...there's an over 100" spread in seasonal snow total from the western county line and eastern county line. And the ones on the western county line like J.Spin and Hanksville are actually at lower elevations than the spots to the east. Where else can you get 180-196" at 400-900ft elevation while 1,000+ft gets 80-100"...all in the same county? Even in Stowe we had a 100" spread over about 5 miles (actually 176" over 5 miles and 3kft difference), but that's the norm around these parts with orographics.

Oh yeah by far if you are talking precipitation amounts (raw QPF). He almost always over-states the effects of orographics in his area...he mentions upslope just as much as I do, though up here you can actually see it in annual precipitation climo. A coastal front will produce more QPF than any orographics in his area. You really need a "wall" of terrain where it uniformly goes from low elevation to higher elevation, such as from ORH northward where its a more linear barrier to eastern flow.

Ahhh the classic unblocked flow depositing the heaviest precipitation downwind of the topographic barrier. I wonder what the Froude Number would be for that event in the Tolland Hills?

Yeah that's a whole other level of screw. That's not a "models showed big hit but we got fringed" or "the rug got pulled out 12 hours from start time." That's a "perfect storm track that delivered 20"+ amounts all around us while we got 3-6 inches." That synoptic set up 10/10 times would deliver big snows.

Yeah that would've been the one that caught a lot of people off-guard that he's thinking of... I remember leading up to that event no one knew if it'd be feet or like 3-6" of slop. Wasn't there a ton of model mayhem before that one, along with marginal temperatures? There are a lot of WTF posts in that thread when people woke up that morning after getting pummeled all night....along with the posts from RI posters of dim moon showing through while it snowed 2-4"/hr in CT and MA. That storm takes the cake for most obscene screw zone ever. Never seen anything like that. It was like a standing wave of air that was always descending right over the same area. You can picture the massive lift in Mass as that moisture comes ashore, then huge banding over CT, but just like a stationary wave of sinking air over RI.

Actually looking at December 2003, I forgot what an obscene period that was for two weeks in VT. I need to live vicariously through these types of patterns for the recent drought of big storms, haha. The Eden Co-Op had 72" in 13 days. Jay Peak Co-Op had 124" in 13 days (this is hard to believe at an average of 10" per day). Hanksville Co-Op had 61" in 13 days.

My area in VT got destroyed that following December 2003, where some of the NOWData sites show 60-90" monthly totals. December 2003 was probably the closest thing to what E.Mass experienced this past winter, except there were several thaws mixed in, whereas last winter's blitz had no thaws. 12/2003 monthly totals were around 5 feet I think at BTV but some of the mountain Co-Ops got crushed. Jay Peak Co-Op...154" (1,800ft) Eden Co-Op...86" (about 30 minutes north of Stowe) Hanksville Co-Op... 78" (25 minutes southeast of BTV) South Lincoln Co-Op...71" (45 minutes southeast of BTV) Worecester Co-Op...70" (next town east of Stowe)

I was just SW of the Albany area then...my last winter living there and it included 50" in 10 days. This map likely isn't accurate outside the ALB area, as that's where this TV station focuses on. I remember we were all watching the news and they were doing live coverage as the state shut down the NY Thruway, counties were under states of emergencies, that deform band meant business. Our town had 25" per the PNS. In the core of the deform band west of us there were some pockets of 36-40" recorded. Christmas Day Storm, 2002.

This will always be a favorite of mine just because it snowed 24" during Christmas Day. It was timed perfectly that it started early in the morning, and during Xmas morning activities it was just steady 1"/hr, though still not overly impressive until 3pm when it seemed to go crazy with 3-5" per hour rates. I just remember eating Christmas dinner and then finding like another half foot fell during that time. The whole family outside shoveling later at night as it continued to pour snow, on Christmas Day. Drove the grandparents home across town and couldn't stop at red lights as we'd never get rolling again. Blasting through snow banks that threw snow up the windshield and over the SUV as the road crews could only clear main roads, side streets had 12-18" since last plowing. I'll always love knowing I got to experience a two-footer on Christmas Day. Not the day before or after...but right there on Dec 25th.

Great shot! Keep that one save on an external hard drive to show the boy when he's older. In fact everyone should back up their photos from last winter, one crash on the computer and you can't get that back.

That radar sums up last winter, haha. Just pummeling eastern New England, especially Mass/BOS. Aimed right at BOS.

I've seen this posted a bunch on ALY and OKX social media pages

Check out ALY's FB page...they are getting crushed for that forecast. 10-18" forecast for most of their area and not a single flake yet.

Man OKX is getting slaughtered on social media. ALY is having just as big a busy but luckily not many care about that area haha.

Yeah, the EURO has gotten better looking in NNE in the recent runs, lol. Definitely N/E of where it was.

Oh I think you are right...wasn't a comment about your PBP but more that this seems to be a theme a lot. Models will show a west solution then within the final 12-24 hrs it keeps burping east. There must be something in the model algorithms that cause them to wrap these systems up too early, when in reality they take a little longer to really go to town.The further north it gets helps me. If it could go NNE instead of NE, it's definitely helps up here.

Haha I reread a thread from Jan 2011 where that poster wxwatcher from SNH lost it on Messenger for all the east trend posts...because basically anyone west of ORH was becoming afraid of only seeing flurries with every RUC run that "ticked east." Then they got buried out in GC with a deform band later in the thread, so who knows.In this case though I think the east trend has to be watched. There's too many meso models way east, though it would suck to see the King fall on it's face to the GFS or something lol.