ORH_wxman

Yeah the 1950s and 1980s were pretty big outliers that can skew the look. The 1950s were dreadful for snowfalls 6"+ in both categories over 6". Even worse than the 1980s....they seemed to try and make up for with lots of 3.0-5.9" events, but the 1956-1957 season kind of skews that decade too if we want to dig deeper. That winter had 11 events of 3.0-5.9" and ZERO 6.0"+ of any kind. No other year in the entire record even had 10, nevermind 11....2002-2003 was closest with 9, though unlike 1956-1957, the incredibly prolific 2002-2003 also had 2 events of 6-11.9" and 3 over 12".

Well I just made it....lol....I had the raw file for years, but I had to update it for the most recent decade.....here;s the raw data by each single year: Snowfall frequencies at KORH by year Year 3.0-5.9" 6.0-11.9" >= 12" 1950-1951 5 0 0 1951-1952 8 2 0 1952-1953 5 2 0 1953-1954 3 1 0 1954-1955 3 1 0 1955-1956 6 6 0 1956-1957 11 0 0 1957-1958 3 2 4 1958-1959 5 2 1 1959-1960 4 1 1 1960-1961 7 2 3 1961-1962 3 2 2 1962-1963 5 4 1 1963-1964 5 3 1 1964-1965 7 2 0 1965-1966 2 2 3 1966-1967 4 4 2 1967-1968 4 4 1 1968-1969 3 2 2 1969-1970 7 1 1 1970-1971 4 6 0 1971-1972 5 3 2 1972-1973 3 1 1 1973-1974 2 2 0 1974-1975 7 1 1 1975-1976 2 2 1 1976-1977 6 4 2 1977-1978 4 4 2 1978-1979 7 1 0 1979-1980 3 1 0 1980-1981 2 2 0 1981-1982 4 3 1 1982-1983 1 0 3 1983-1984 3 5 1 1984-1985 6 0 0 1985-1986 4 1 0 1986-1987 2 5 2 1987-1988 4 3 1 1988-1989 4 0 0 1989-1990 3 3 0 1990-1991 3 2 0 1991-1992 3 1 0 1992-1993 6 3 2 1993-1994 7 3 2 1994-1995 0 0 1 1995-1996 6 5 4 1996-1997 3 1 2 1997-1998 5 1 1 1998-1999 2 4 0 1999-2000 2 2 0 2000-2001 4 3 2 2001-2002 2 3 0 2002-2003 9 2 3 2003-2004 5 1 1 2004-2005 8 6 1 2005-2006 3 2 2 2006-2007 3 1 1 2007-2008 4 5 0 2008-2009 4 4 1 2009-2010 4 3 0 2010-2011 4 1 4 2011-2012 3 1 1 2012-2013 2 5 2 2013-2014 4 4 2 2014-2015 4 3 3 2015-2016 4 0 1 2016-2017 5 2 2 2017-2018 3 2 3 2018-2019 5 3 0

I decided to look into the frequency of snowfalls by magnitude at ORH based on the discussion by Tip and Ray....here's what I found: Now obviously a couple things stick out....small event between 3.0-5.9 have generally declined while larger events over 12" have increased. The middle run-of-the-mill warning criteria events have not really changed....slight increase. But something to keep in mind, the data is somewhat noisy. See the decade of the 2000s with the big increase again in small events and moderate events....but not really 12"+ events.

Melt ponding is supposed to occur more readily on first year ice than multiyear according to the literature but let's say that is flawed analysis....if melt ponding was truly getting harder because first year ice is somehow getting so bad and other factors now contribute more to melting because of this, then we would expect the NSIDC area in late June to significantly over-predict the amount of ice left at the end of the season. We haven't really seen that in recent years....except 2016. But it didn't happen in 2017 or 2018. It doesn't look to happen in 2019 either unless something pretty crazy happens in the next couple weeks. The late June area data (which is a proxy for melt ponds) told us that we had a good chance for 2nd lowest but not a good chance for lower than 2012's record. There's nothing glaring that says that data missed some sort of smoking gun on additional melting.

Those first two had big -NAO help. 2015 did not though but we got an amazing nearly-standing PNA wave in a perfect spot. When it doesn't line up like that we often have to be at the whim of the unmanned firehose....ala 2013-2014, 2016-2017, and last year...last year we got somewhat unlucky but that's the way it goes. We got lucky in some of those previous years. Obviously we all root for a -EPO since a +EPO is garbage but I will also root for some Atlantic help.

The role of the cyclone in 2012 is overstated imho. The ice was in terrible shape before it hit. I'm not really convinced it added that much to the losses. Maybe a couple hundred thousand sqkm or something. 2012 already had the highest percentage of melt ponds by the end of June suggesting a new record was likely. It was significantly lower on SSMI/S area than other years including 2019...it's the main reason I didn't think we'd set a new record this year despite this being the most favorable melt year in a while. It just didn't quite stack up to 2012's early melt ponding.

The sea ice argument was the reason given from 2009-2013 but now it obviously doesn't work given the recent +NAO. I've still heard it as relating to the recent -EPOs we've seen. We'll see if that holds up too in the coming decade. Regardless, it would be nice to grab at least a solid month of -NAO in the means (obviously fluctuating is ideal...before Tip makes an angry post about dynamic changes in magnitude)....it's nice not having to rely on the unmanned firehose spraying the right way all the time. A good solid PNA ridge can do the same ala 2015 but those don't seem to lock in place as easily as an NAO block...unless it's 2015 of course, lol.

The NSIDC data I'm using is from their satellite dataset. Specifcally the SSMI/S satellite. Jaxa and U Bremen use the AMSR2 satellite, which is highest resolution of the two. SSMI/S is useful though because it has a pretty homogeneous dataset going back to 1979. IMS uses both satellite and human augmentation of the data based on visual shots of the ice. Here's the FAQ from MASIE/IMS site: https://nsidc.org/data/masie/masie_faq

It will be interesting to see if this product stays below 2012....I suspect it will not, but we'll find out in about 2-3 weeks. NSIDC area is now favored to finish 3rd lowest...we're only 90k lower than 2016 now and 2016 loses about 400k in the next week. So this year needs to kick-start again on area loss to stay pace. Extent is still favored to finish 2nd lowest behind 2012 on NSIDC, Ubremen, and Jaxa.

Yep...there was plenty cold over the CONUS, just not for most of the posters in here....pretty classic gradient with SE ridge in the east actually.

Oh yeah...I wasn't implying that we're screwed because of it. Just a few short winters ago, we had our "Labrador visits Boston Harbor" storyline complete with sea ice that didn't melt until after the spring equinox and snow cover draping the buildings like "Day After Tomorrow" footage. And hell, even since that winter, we've had some pretty good stretches despite the +NAO. But I was mostly rolling my eyes at the "NAO flips positive as soon as summer is over" theme that has been present the past few years. At some point, it would be nice not to have to rely on the EPO/PNA region to bail us out as winter enthusiasts....even though it has bailed us out quite often recently.

We haven't had a full DJFM season average a -NAO since 2012-2013. 2017-2018 was the closest we came on the strength of a big -NAO March that season. But it still finished slightly positive. In fact, here's an amazing stat.....March 2018 is the only month out of any DJFM cold season that has averaged a -NAO since March 2013. January 2016 was just north of neutral as the closest runner up. January 2017 was also close (it actually averaged slightly negative on the Hurrell SLP method, but slightly positive on the Z500 CPC method). But that is pretty amazing. Out of the past 24 winter months, we could only get one of them to be decidedly negative on the NAO.

Our big blocking NAO from this warm season disappears faster than a hair follicle on Kevin's head as soon as October/November swing around.

That paper basically argues the opposite of tip's gradient "fast flow" theme. Kind of reinforces my statement earlier how there is a bit of "flavor of the month" syndrome in the literature. That paper was published right after the epic blocking of 2009-2011 where we had slow moving bombs.

I think the backloaded winters are more of a result to a shift of +PDO/Niño type PAC since 2011 rather than some permanent alteration of the polar jet. Before that, we couldn't buy a blockbuster Feb/Mar for like 7-8 seasons going back to the early 2000s. Instead, we had a lot of front-loaded big Decembers and Januarys in that 2003-2011 time period. I suspect this will shift back again once we have a more Niña/-PDO look again like we did in the late 2000s/early2010s. You may be right about the increased blockbuster storms though and the Gulf Stream anomaly since 1996 though. I'm not sure how accurate those maps are on a small scale like that, but certainly higher SSTs up against lower anomalies to the north would be a good breeding ground for cyclogenesis.

Well, it sounds like a subjective analysis then by you on other people's posting behavior. Not sure I can really help other than the below explanation: If you go back through the beginning of this thread and previous Arctic sea ice threads, you'll note that IMS hasn't been used. It's been consistently NSIDC and JAXA...sometimes U bremen and previously Cryosphere Today (now defunct..but they used NSIDC data). I don't know a ton about IMS but my little experience with it from sheer recollection back to the 2009-2013 days is that it seems to lag the other datasets significantly. It will "catch up" to them eventually if it looks like it is deviating on a trend line. That is my guess on what happens this year as well. We won't have to wait long to find out.

Here's some sources....the record we discuss isn't supposed to be about what it means longer term. Most of us know the longer term trend is down. But records are interesting to all of us in the weather community. Why do we sit around and track the thermometer at 101F on a hot summer day when the record is 102F? Does it really feel much different from 99F? Of course not, we're just tracking whether the record gets broken or not. FWIW, we've discussed when we think the first total melt out (definition below 1 million sq km of extent) will be in here: https://www.americanwx.com/bb/topic/40881-when-we-will-see-an-ice-free-arctic/ https://www.americanwx.com/bb/topic/46677-when-will-the-2012-arctic-ice-extent-minimum-record-be-broken/?page=3 It does not appear we will set a new record this year based on JAXA, ubremen, and NSIDC. We'll see about the IMS plot you reference but is suspect that will flatten out at some point. https://docs.google.com/viewer?a=v&pid=sites&srcid=ZGVmYXVsdGRvbWFpbnxhcmN0aXNjaGVwaW5ndWlufGd4OjU1OGIwZWI0NGI2ZDI5YTM https://seaice.uni-bremen.de/sea-ice-concentration/ https://ads.nipr.ac.jp/vishop.ver1/vishop-extent.html

Area and extent loss have slowed to a crawl the last couple days. We're now behind 2012 by about 300k on extent and 200k on area.

1980s/early 1990s probably skewed some perception too for those of us that remember. They are truly putrid snow years that are unrivaled in the record...that period sticks out like a sore thumb. There were some pretty bad periods between the late 1920s and early 1950s but none of them could match that 1979-1980 though 1991-1992 stretch. So while the prolific snow producing storms since 2000 are certainly note-worthy, they are especially glaring when compared against the backdrop of the 1979-1992 period. It's like "let's take the most prolific 15 or so years and compare them against the worst 15 year stretch...I bet that might make people talk"...for our generation, say those born from the 1970s to early 1980s, we had both periods as really our only experience for SNE winter...and they essentially happened back to back save maybe a brief "shoulder period" in the mid to late 1990s. Its hard to really say what "normal" is too when it comes to New England snow climo. I can spit out the numbers of course...I know them all like the back of my hand....but it's the way we get to those numbers that is the question. We've had so many periods that were seemingly unmatched in the record. The late 1950s through early 1970s produced nary a below average snowfall season in SNE. Esp over the interior...the consistency was incredible. So was the cold. They were much snowier and colder winters than the previous 30 years. Now, after a long period of declining-in-frequency KU events from the 1970s through the 1990s, we all of the sudden see the massive reversal and now the winter spits out a 20" KU like Halloween candy being tossed out to trick our treaters. Btw, I do agree some of the individual storm numbers are somewhat inflated versus 30+ years ago due to measuring technique, but that only explains a smaller portion of the situation. Anyways, everyone is going to have theories and thoughts on the matter, but nothing will be better than another decade of data and then another decade after that to see what happens. I can guarantee none of the literature in the late 1990s and early 2000s saw the snow boon years coming in New England.

Agreed. The increased moisture just is not enough magnitude to explain it. We've had like a 4% increase in WV here since the 1980s. There are other factors...and granted, some could still be related to climate change, but perhaps not as directly.

Well that differential in SSTs was less in 2016...my comment was that why would we expect it to remain there? The gradient is all relative. Is there a reason to expect a hot spot in the central PAC that warms faster than the equatorial PAC on a magnitude that makes the 2016 super Niño less effective? (I.E do we expect the subtropical PAC to continue to warm wayyyy faster than ENSO like we saw between 2013 and 2016? No probably not. At least that is what most of the literature points to. Of course, we should keep in mind that the literature is not very accurate when it come to differential warming. It can do okay when it comes to the global trends but regional tends to get tougher. So maybe it's a new normal...but I am typically skeptical of claims like that and for good reason. They usually revert back closer to the global trendline. The exception may be the polar regions where ee expect some pretty enhanced trends...and even some wildly reversed trends at times like seen in Antarctica. But most of the earth in between seems to ebb and flow with the an underlying warming trend.

The lack of gradient between enso region and the rest of the PAC shouldn't be a new norm unless there is a distinct reason to believe that the rest of the PAC is going to have an underlying warming that is greater in magnitude than the ENSO region. The equatorial cold tongue has been an issue in observations vs climate models but the warm pool to the north of there that has set up off western Mexico and out into the central PAC is a newer phenomenon that is unlikely to remain there relative to the rest of the basin and vs ENSO region in the equatorial PAC. Of course, maybe it will remain...we don't know for sure...just like we didn't know for sure if the monster blocking of 2009-2013 would remain or the positive NAOs of the late 1990s. Odds are though it will pass onward to something different in a relative sense.

That tool on NSIDC uses the 5 day running mean instead of daily values.

IMS is a deferent source than JAXA or NSIDC and it looks like that graph doesn't have any data beyond late July.

The field as a whole tends to overreact to the most recent events. In the late 1990s and early 2000s, there was a lot of stuff coming out how global warming was causing more +AO/+NAO conditions due to the PJ retreating north and intensifying/enhancing the vortex near the pole. Then by about 2011, the reverse started showing up...Arctic amplification was causing huge NAO blocking and massive "warm Arctic, cold continent" winter patterns and prolonged PV invasions due to "wavy jet" theory. This persisted for a while and now we're starting to see some new narratives like the enhanced subtropical ridging due to Hadley cell expansion, etc. To me, it's mostly flavor of the month. It's not that the theories are wrong, it's just that each variable seems to get too much credit during the seasons where the effects are most noticeable.