ORH_wxman

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.

2016 looks like it had a lot more easy pickings after 8/10 for losses than this year. If parry stait melts out then that could add some to 2019 but 2016 looked easier:

Why do we think 2019 will act more like 2016 than 2012 after August 10th?

We've fallen 350k behind 2012 on area despite extent still being very close. We're probably going to need a big compaction pattern to keep extent in the running through the end of this month.

2017 was decently snowy...though not excessive. But we haven't had a snowy Niño December since 2009. Were kind of due for one even though they are typically not favored. We've gone 3 horrendous Niño Decembers in a row since '09....maybe the excessive blocking we've seen recently will be able to manifest itself early this winter. That's typically a requirement for a snowy Niño December. In La Niña, we often can get away with less blocking in December. Not in El Niño. Of course, it could be warm neutral too. We'd be less reliant on blocking if it was but we'd still want to see it.

Seems like we're favorites for either warm-neutral or weak Niño. Obviously things can change but the subsurface doesn't look overly impressive and the model forecasts seem to agree.

2012 has expanded it's area lead to 210k....the best chance for 2019 is if the Laptev can retreat further than 2012. That's the weak spot when comparing year over year.

Extent definitely has a better chance to beating 2012 than area. We're 170K behind in area now and 2012 doesn't slow down any time soon. We'll need some breathtaking losses to keep pace. If we have enough compression of the pack though, extent could still challenge even if area does not.

On extent or area? I think 2007 both extent and area are very good chances to be surpassed by 2019...2016 has a good chance on extent but not as good for area. Prob like a 50/50 chance or less to pass 2016 area.

I agree with the low chance of beating 2012 at this point. I wanted to see a pretty good sized lead heading into late July/early August. I might go higher than 3% on extent but not by a lot. Maybe 10-20%. For area I probably wouldn't go higher though as we slightly trail 2012 in area.

I mentioned before that Atlantic and CAA may prevent us from getting a new record. Much more ice there this year than 2012. But we still have a chance if ESS/Laptev can melt back far enough. We're tied for area right now. 2012 has some epic losses in early August though which is why I'm still a bit skeptical in addition to just looking at the individual regional concentration maps.

Still a chance, but pretty low odds IMHO. We'll need some very warm August weather. Atlantic and CAA are a problem further out in time. We'll need the ESS/Laptev sectors to melt toward the pole further than 2012 did to have a chance because the ATL and CAA are going to finish higher than 2012.

Yes, most likely....we've already seen some slowing the last few days. I'm not sure this year will be able to keep pace with 2012 going forward with that pattern. But we'll see.