HYCOM may have many issues but I think one front where it is particularly useful is in comparing sea surface temperatures.
https://www7320.nrlssc.navy.mil/hycomARC/navo/arc_list_arcticsst.htmlA few things are interesting to note comparing this year with last year and 2012/others --
1) The tongue of cold SSTs southeast of Newfoundland is more prominent and colder than any recent year besides 2014. Compared to 2012, the change is particularly dramatic. Temperatures immediately SE of Greenland have also decreased this year.
2) Despite this cold in the NW Atlantic, there is a strong area of warmth comprising the Gulf Stream, appearing warmer than usual and extending all the way to the NW of the UK/Scandinavia.
3) On the Pacific side, things are colder than they have been in recent years where the ridiculously resilient ridge had formerly been residing, west of the Rockies.
4) Elsewhere in the Pacific, especially in Barents/Okhotsk, things are *substantially* warmer than normal. In fact, Okhotsk is an order of magnitude warmer than any other year in recent history, and Barents is similar.
I suspect the above will contribute to Pacific-driven warmth melting the Arctic this year. As the extent/area maps already show, we are seeing substantial melt beginning along the coastlines of Alaska and NE Siberia. I expect this will continue as the heating of Okhotsk/Barents much earlier than normal (due to their possibly record-early dearth of sea ice) means that storms approaching from this direction will have much more insolation to take advantage of, and that heat will ultimately be deposited/resolved over the Arctic Ocean -- first Chuchki, Beaufort, ESS, and then the CAB.
While the above isn't too different from the story of the worst years we've seen, it is going to be occurring far earlier than ever before, and impacting an Arctic Basin where thicknesses are thinner than ever before, particularly over the Beaufort Gyre, which has no ice in excess of 2.5M in thickness (contrary to even last year, where 4M+ ice abounded). This means that we may see melt-out approaching the CAB a month or so before years like 2012, which greatly ups the chances of a blue Arctic this year.
The SST changes over the Atlantic would also seem to lend themselves to the potential for enhanced LPs/heat flux over Greenland and the FRAM/et al as the melt season progresses, given the higher SSTs than usual NW of the UK/Scandinavia. The question is when this begins to manifest -- the combination of LPs taking advantage of the warm Pacific SSTs should encourage blocking highs over that sector of the Arctic, and as those get stronger and stronger as more heat accumulates through NHEM summer, I wonder if the strengthening gradient between hot/cold over the NW ATL will favor severe cyclonic activity over Baffin/FRAM/Kara, with the contrast between PAC/ATL perhaps worsening conditions beyond any year we have seen so far.
This also has a few implications for melt season IMO -- we are going to have a sledgehammer impact the ice that normally takes the entirety of summer to thaw/melt, so that may go early, but it still may go relatively slowly. Though it will most definitely go.
On the flipside, the cold Atlantic SSTs and remaining thick ice in Baffin/Hudson will also melt out anyways, but it could easily hold on a month+ longer than normal (IMO). This means that the cliff induced by melt-out of that ice that normally comes in June may come in late July/early August -- holding up area/extent to only slightly lower than normal numbers before a gut-punch comes as all the ice that was going to melt out anyways does so quite rapidly.
Baffin ice could also hold on longer than normal due to the massive export imminent/ongoing through Nares, which is some of the thickest ice in the basin & multi-year to boot. Perhaps some of this makes it through the summer and drifts all the way down past Quebec, jump-starting the freezing season more rapidly than normal for the banks off Newfoundland even?