The 2018/2019 freezing season

[El Cid]

The late crazy weather is almost behind us now.

Is it?
There still seems to be a tremendous amount of heat coming from the Pacific. Attached 4 days ECMWF forecast

[Neven]

Well, every winter is a bit crazy now. I was referring to the tight band of isobars and 60 hPa pressure difference between the high on the Pacific side and the low on the Atlantic side. One more day of that and then the high pressure takes over. Sure it will bring in heat from the Pacific, but it will also bring clear skies.

[Csnavywx]

Barrow is at -2C this morning under hours of clear skies. Barter Island at -1C. Not going to get much freezing done in this pattern. CAA will have to make up the difference.

[Eco-Author]

The CAB chart is crazy. But I believe it will hit the physical limit soon.

Looks as if a lot is getting pushed into CAA...? 

[uniquorn]

Update on Mercator 300m salinity, aug1-sep30. (every 2days, scale is not static)
http://bulletin.mercator-ocean.fr/en/permalink/PSY4/animation/3/20180801/20180930/2/4

[Niall Dollard]

Barrow is at -2C this morning under hours of clear skies. Barter Island at -1C. Not going to get much freezing done in this pattern. CAA will have to make up the difference.

Yes. Not much freezing in this part of Arctic and right up the Russian side.

But then again it isn't exactly the big Chinook and melt you were talking about 4 days ago either. 

[Csnavywx]

Barrow is at -2C this morning under hours of clear skies. Barter Island at -1C. Not going to get much freezing done in this pattern. CAA will have to make up the difference.

Yes. Not much freezing in this part of Arctic and right up the Russian side.

But then again it isn't exactly the big Chinook and melt you were talking about 4 days ago either. 

Wouldn't get too comfy. Downsloping flow doesn't really get going until late tonight and tomorrow over NW Alaska as the core of stronger southerly flow aloft shifts eastward from the Strait. Shows up particularly well on the 850 charts. Not much has changed from when this was a 96 hour forecast.

[Aluminium]

September average temperature in some locations of Chukotka:

Uelen (Bering Strait) - 8.6°С. 5.1° above normal September, 2.1° above previous highest (2007), 1.9° above normal July.
Pevek (East Siberian Sea) - 9.0°C. 6.0° above normal September, 1.3° above previous highest (2007), 0.3° above normal July.
Anadyr (Bering Sea) - 9.9°C. 5.3° above normal September, 2.2° above previous highest (2010), 1.7° below normal July.

Forecast is warm again.

[Neven]

Update on Mercator 300m salinity, aug1-sep30. (every 2days, scale is not static)
http://bulletin.mercator-ocean.fr/en/permalink/PSY4/animation/3/20180801/20180930/2/4

Is this still real? And if so, any explanations?

[be cause]

the dmi 80'N records continue to be shattered every day .. today was the fifth in the sequence . 2 metre temps remain over 8'C above normal .. that is a little below -4'C rather than heading toward the daily norm of nearer -13'C. b.c.

[uniquorn]

Update on Mercator 300m salinity, aug1-sep30. (every 2days, scale is not static)
http://bulletin.mercator-ocean.fr/en/permalink/PSY4/animation/3/20180801/20180930/2/4

Is this still real? And if so, any explanations?

I think the animation posted accurately reflects the Mercator model on the site linked though, as we all should be aware, it's not real. To paraphrase FOoW:
Warm, salty Pacific water [appears to be] flowing up through the Bering strait on the Alaskan coast, then sinking into Barrow channel into the Arctic ocean at 30m and 100m.
There appears to be some evidence of that on the animations at those depths and a suggestion of similar flows on the Siberian side of the Chukchi Plateau.
Hycom model agrees with incoming salinity through the Bering Strait at 0m but I'm not aware of another 300m model.

Perhaps the buoy analysts can confirm or refute.

[Eco-Author]

Update on Mercator 300m salinity, aug1-sep30. (every 2days, scale is not static)
http://bulletin.mercator-ocean.fr/en/permalink/PSY4/animation/3/20180801/20180930/2/4

Is this still real? And if so, any explanations?

If it was a Kelvin wave from the deep waters, this could change the whole dynamic of the arctic: lowering freezing temps, holding more heat in summer, drawing up a long chain of warmer water? and likely half hidden under the existing pack as it looks to only show around the edges!  Wondering if the 'bobbing effect' of so many smaller bergs might serves as a pump to circulate itself.

[GoSouthYoungins]

DMI 80N has been wicked hot recently (not counting the melting season when the temps are bound toward freezing) and there have been records about every other month.

[Neven]

the dmi 80'N records continue to be shattered every day .. today was the fifth in the sequence . 2 metre temps remain over 8'C above normal .. that is a little below -4'C rather than heading toward the daily norm of nearer -13'C. b.c.

Indeed.

[slow wing]

U. Bremen's false colour ice concentration maps show a week's action in the Arctic basin, ending on the map just released, 2018-09-30...

[oren]

U. Bremen's false colour ice concentration maps show a week's action in the Arctic basin, ending on the map just released, 2018-09-30...

Large region of ice winking out in the ESS, balanced by continued growth in the Beaufort and Greenland Sea.
I wouldn't be surprised if today's JAXA extent change comes in slightly negative.

[Neven]

Large region of ice winking out in the ESS, balanced by continued growth in the Beaufort and Greenland Sea.
I wouldn't be surprised if today's JAXA extent change comes in slightly negative.

Slightly positive still, 10K, but maybe tomorrow.

[johnm33]

"Is this still real? And if so, any explanations?"
 another possibility is that the saline water is moving across the Beaufort at depth and is backing up in the direction it's coming from and merely leaking into the Beaufort gyre following the shelf bathymetry. That is it's Atl. water.

[uniquorn]

I've sent Mercator an email.
edit: The tip of the ESS arm from polarview yesterday (cropped and enhanced)

[Shared Humanity]

Impressive retreat of the ice north of Franz Josef.

[slow wing]

U. Bremen's false colour ice concentration maps show a week's action in the Arctic basin, ending on the map just released, 2018-10-01...

[Aluminium]

September 27 - October 1.

[El Cid]

Can someone explain me how so much heat can intrude towards the N.Pole from the Pacific? How can that happen? Any specific mechanisms?

[sark]

Can someone explain me how so much heat can intrude towards the N.Pole from the Pacific? How can that happen? Any specific mechanisms?

The Bering & Chukchi are HOT.  +4-5C.  Seems to me like it's throwing a high and making DMI's 80N temp chart plateau.  I dunno if that's a good explanation.

[gerontocrat]

I'm no meteorologist, but

Low pressure centred over Novaya Zemla (heading East), high pressure over South Beaufort Sea encourages winds to flow northwards from a warm Siberia and /or Pacific?

Maybe yet another anecdotal example of the hypothesis that AGW / Climate Change has made it more likely that when a weather pattern becomes established it will dig in for many days?

Meanwhile, sea ice may decline today, or at least be lower than average increase. Depends whether that warmth melts more stuff on the Pacific front than the cold increases extent in the CAA and Greenland Sea.

14 seas defined by NSIDC in the Arctic, 14 different climatic and weather environments. Even the Hudson has 2 distinct areas - the smaller and almost enclosed Foxe Basin in the North that looks like it is going to freeze very soon, and the the main basin that looks like it will hold out for a bit longer.

[Aluminium]

Really hot. Pevek and Uelen got +14.5°C and +14.0°C yesterday. Both are 2.8-2.9° above previous highest temperature in October. Wrangel Island also got the highest temperature in October (+7.6°C, 1.3° above previous).

[johnm33]

Can someone explain me how so much heat can intrude towards the N.Pole from the Pacific? How can that happen? Any specific mechanisms?

I'll take a punt, Amundsen is not huge lets say 300 by 100 km and the tides are not huge .2-.6m but it's the only game in town. The tidal forcing twice a day drives a current across the Canadian/Alaskan mainland that detatches the incoming Pacific water from the coast at times and consistently provides resistance to it's ingress. The Pacific water backs up and flows instead into the deep west of Chuckchi Plateau here it meets and mixes with the increasing flow of Atl. water coming past the Lomonosov ridge. Some fraction gets caught up in turbulence caused by the tail end of the Amundsen driven current. Just as Amundsen drives water out twice a day so it draws it in, from the general direction of NSI but likely from just north of Chuckchi plateau. The easiest fraction of water to move is the surface so the Pacific waters are also drawn into the area where the Amundsen bound surface current begins.
   It's well worth looking through the various parameters at the link, i do full tilt/full screen, there's nothing that looks too different to other models.
The link done.

[uniquorn]

Today's ecmwf waves and  temps from windy.
edit:@johnm33 -forgot the link?

[bbr2314]

It is very interesting that the September snowfall situation resulted in the #1 extent reading in the satellite record for North America.

Snowfall has been shown to be a substantially mitigating factor to some components of spring melt (i.e. more extant cover = higher albedo = colder airmasses into / surrounding parts of the Arctic, although +continental snowfall also acts to further advect oceanic heat towards the Arctic when continental cold airmasses discharge into the Pac / ATL / etc).

But what if the mitigation is contingent on extant sea ice being in place? That is, IF snowfall across the continents increases much faster than sea ice in coverage, leaving a large portion of the Arctic blue while much of lower Russia / the upper US gets covered, does that put the cold airmass discharge -> oceanic heat advection pump feedback into overdrive, overwhelming any other benefits?

Looking at the way this September has evolved into October one could seemingly make the case for the situation over North America being driven by the +500MB anomalies that are highest over the Bering.

[uniquorn]

Ascat, day264-274(2.6MB).
Worldview, end of the Beaufort arm, oct1
Refreeze and export into the CAA and Fram Strait but no clear signs of refreeze on the ice edge in the Arctic Ocean. Compaction from Pacific and Atlantic sides gives little chance of refreeze between opening leads. Perhaps the recent flashing in/out on amsr2 has been snow on thin ice.
Hopefully the Mclure Strait will freeze completely before all the thicker ice escapes.
edit: That gap north of SZ is going to be trouble.
Reminder that viirs brightness temperature, band15 is handy when Worldview goes dark.
Worldview, Ellesmere, oct2. https://tinyurl.com/yau9af5c
Looks like a lemon squeezer

[litesong]

The late crazy weather is almost behind us now. I expect refreeze to pick up after tomorrow, with the ice edge expanding rapidly towards the Atlantic, etc.

Yes, High Arctic temperatures will drop lower sometime (soon or already?), since the present High Arctic temperatures AVERAGE 7degC over average. But as Arctic freezing increases, AGW on the average, will cause present High Arctic temperatures to remain above their 60 year averages.   

[Aluminium]

Wrangel Island also got the highest temperature in October (+7.6°C, 1.3° above previous).

+9.3°C reached today. So 3.0° above previous highest which was in 2016.

[Niall Dollard]

Reminder that viirs brightness temperature, band15 is handy when Worldview goes dark.
Worldview, Ellesmere, oct2. https://tinyurl.com/yau9af5c

Thanks for tip Uniquorn. Darkness is not far off Eureka now. Currently down to -20 C there.

[gerontocrat]

The late crazy weather is almost behind us now. I expect refreeze to pick up after tomorrow, with the ice edge expanding rapidly towards the Atlantic, etc.

Yes, High Arctic temperatures will drop lower sometime (soon or already?), since the present High Arctic temperatures AVERAGE 7degC over average. But as Arctic freezing increases, AGW on the average, will cause present High Arctic temperatures to remain above their 60 year averages.

GFS has temp anomaly increasing from 2.7 (now) to 4.5 celsius by Sunday 7th (and staying well above +4 for the week after). The image suggests this could give DMI North of 80 a substantial bump up.

As yet I see no reason to see slow extent gain changing to average increases for the next week or so. Having made a prediction I have also prepared my disclaimers in advance.

[magnamentis]

Can someone explain me how so much heat can intrude towards the N.Pole from the Pacific? How can that happen? Any specific mechanisms?

strong southerlies over mostly warm / much warmer than average waters almost consistently for the last few weeks with a few outliers only.

considering where the only ice that can still melt is and considering the winds and temps as well as the water temps that surround the main ice pack, it's still possible to see drops and/or that we remain flat for another few days.

further, since we have so many discussions about the different years and areas, where happens what and when, i recommend to always consult the global development as well. globally we are quite steadily moving around lows over the last few years which makes totally sense, putting into account that we are dealing with "global warming" and it's effects and not the other way around.

[bbr2314]

The dynamic between HB / Chukchi + Bering will be very interesting to watch unfold. With snowcover at all-time highs for this time of year across North America, an extremely early refreeze of HB appears very likely.

At the same time, Chukchi and Bering are scorching, their adjacent landmass is less snowy vs. normal compared to the Canadian Shield, and the pair have the Pacific importing very saline warmth at depth (ongoing as I type).

The regime has shifted entirely from the days when Chukchi + Bering would be barely and seasonally ice free while HB was always seasonally ice free. We now have a ratio that has swung wildly towards more ice coverage in HB relative to Chukchi and Bering, which has worsened exponentially since 2012 (would be curious to see this graphed, actually  -- someone please attempt to prove me wrong  ).

Will an extremely early HB refreeze encourage even deeper / more persistent troughing than last winter across North America in 2018-19, and will this exacerbate a semi-stationary rex block over the Bering / Chukchi? Stay tuned, but it seems quite possible. If the opening days of the alleged "refreeze" thread are any indicator, both PAC and ATL fronts will be in worst-ever conditions come springtime maximum.

I would also think that an abundance of FYI relative to normal in certain areas come spring 2019 will result in a drop like this year, but worse (recall when Kara and HB both poofed seemingly overnight, after enduring with very high albedos until that point).

PS: if DMI is correct it looks like we see no real extent gains through 10/7 due to continuing melt / compaction across both PAC and ATL fronts. Some gains toward Beaufort offset by the hoopla elsewhere. Wonder if we end up worse than 2012 soon?

[Csnavywx]

Can someone explain me how so much heat can intrude towards the N.Pole from the Pacific? How can that happen? Any specific mechanisms?

Something called an atmospheric wave break. In this case, it was a combination of a cyclonic wave break (Rossby wave breaking is a complex but important process in the atmosphere -- picture it somewhat analogous to a sea wave that breaks as it approaches shore) that was reinforced by moisture and heat flux from both ex-TC Trami and unusually high SSTs in the region. All of these contributed to it.

We have seen a propensity towards very large and anomalous ridges and heat flux into the high Arctic during the cold season in the last few years. The reason for this tendency is still under research -- though it's interesting to note that some model simulations (like Nakamura et. al's Blue Ocean experiment paper) have a strong tendency for height rises over the Arctic in autumn and winter and part of it has to do with the extra heat flux from the ocean and a coupling feedback from the stratosphere. That's probably not the whole story, but probably part of the puzzle.

[bbr2314]

Officially have decent amount of second year ice that will survive in Foxe Basin. Refreeze now underway and should be mostly done in 10-14 days IMO. Very early / at that time the NRN reaches of HB should also begin to freeze.

Wonder if we officially see multi-year ice classified this time in 2019?

[slow wing]

U. Bremen's false colour ice concentration maps show a week's action in the Arctic basin, ending on the map just released, 2018-10-02...

[El Cid]

Can someone explain me how so much heat can intrude towards the N.Pole from the Pacific? How can that happen? Any specific mechanisms?

Something called an atmospheric wave break...

...We have seen a propensity towards very large and anomalous ridges and heat flux into the high Arctic during the cold season in the last few years. The reason for this tendency is still under research -- though it's interesting to note that some model simulations (like Nakamura et. al's Blue Ocean experiment paper) have a strong tendency for height rises over the Arctic in autumn and winter and part of it has to do with the extra heat flux from the ocean and a coupling feedback from the stratosphere. That's probably not the whole story, but probably part of the puzzle.

Thank you all for the answers!

It seems then that the warmer/less ice-covered/moister Arctic has a tendency to "suck in" warmer air from the mid-latitudes which is sort of a positive feedback: the warmer Arctic begets a warmer Arctic.

I wonder what that means for mid-latitude winters, since the past five years (with an ever warmer winter Arctic) the warm Arctic-Cold Continents theory has not really been true: other than bbr's favourite Quebec/Canada region, the continents were actually quite warm as seen on the attached chart:

[oren]

With snowcover at all-time highs for this time of year across North America, an extremely early refreeze of HB appears very likely.

HB starts normal freezing in the last third of October, but an early start of the refreeze is still possible in the next two weeks. How likely - not sure. Extremely early - IMHO no.

Officially have decent amount of second year ice that will survive in Foxe Basin. Refreeze now underway and should be mostly done in 10-14 days IMO. Very early / at that time the NRN reaches of HB should also begin to freeze.

Wonder if we officially see multi-year ice classified this time in 2019?

According to the quite reliable UH AMSR2 3.125 data, the ice area in HB has been hovering at less than 100km² in the last few days, very similar to the data in previous years. Is this a decent amount of soon-to-be second year ice? IMHO no.
Looking at the two orange locations in Worldview, with all due respect to the Canadian Ice Service I believe the ice they are referring to as having survived to be 2nd year is mostly not there, barring some few tendrils (except in the Fury and Hecla Strait fed by the CAA).

[bbr2314]

With snowcover at all-time highs for this time of year across North America, an extremely early refreeze of HB appears very likely.

HB starts normal freezing in the last third of October, but an early start of the refreeze is still possible in the next two weeks. How likely - not sure. Extremely early - IMHO no.

Officially have decent amount of second year ice that will survive in Foxe Basin. Refreeze now underway and should be mostly done in 10-14 days IMO. Very early / at that time the NRN reaches of HB should also begin to freeze.

Wonder if we officially see multi-year ice classified this time in 2019?

According to the quite reliable UH AMSR2 3.125 data, the ice area in HB has been hovering at less than 100km² in the last few days, very similar to the data in previous years. Is this a decent amount of soon-to-be second year ice? IMHO no.
Looking at the two orange locations in Worldview, with all due respect to the Canadian Ice Service I believe the ice they are referring to as having survived to be 2nd year is mostly not there, barring some few tendrils (except in the Fury and Hecla Strait fed by the CAA).

It actually is there! It has been very cloudy but you can clearly see the ice in the eastern edges of Foxe Basin if you roll EOSDIS past few weeks. Some is evidently very thick. The Canadian ice chart guys know their stuff and if you go into their other maps you can see some of it, though now second-year ice, is still diluted down to 50-70% concentration (but with refreeze now starting in earnest, this will quickly turn to 100%).

Hudson Bay definitely has no extent, no argument there, but Foxe Basin's refreeze immediately precedes HB's, more often than not (I would think).

PS: tonight's 00z EURO is insane. We all know and acknowledge that 240 hours is way out there. But with the consistency of Beaufort + Bering + Chukchi blocking and SSTAs/etc off the charts, there is support for this. Nearly +20C 850s for 10/12 over the Beaufort, with a wide area +20Cish above average! It takes the recent pattern and just continues it.

According to the 00z EURO, the first major North American city of the winter to be buried will be Calgary, with up to three feet of snow expected on the ground by 10/12. At 12z, it forecast 20-24", so this number is trending up (for now).

How is that relevant to the freezing season? Do you know where the cold ISN'T? The Bering!

[uniquorn]

Todays kerfuffled ecmwf waves and temps from windy.

[FishOutofWater]

I think the salinity increase at 300m along the north continental slope of the CAA is real. There was a shift in the winds and the circulation of sea ice from cyclonic in July and early August to anticyclonic in September. The wind shift is best seen by watching the satellite loops of sea ice motion. Although the sea surface height gradient from the western Arctic ocean to the Labrador sea continues to push ice through the channels of the CAA, the general motion of the sea ice in the western Arctic ocean is clockwise now. Clockwise surface rotation tends to bring on upwelling on the north continental slopes of Alaska and the CAA.

I think the wind shift caused a coastal Kelvin wave of shoaling of warm salty Atlantic water from depths below 300m up to the 300m level. I have forgotten who suggested it was a Kelvin wave, but I think that's correct because shifts in wind regimes can cause coastal Kelvin waves.

Extraordinary amounts of warm salty Pacific water have been flowing towards the Barrow submarine canyon, but that water hasn't had the time to reach the CAA and loops show that that water may be rotating clockwise towards the Chukchi shelf margins, not the CAA. The warm water that's sinking in the Chukchi region will likely store heat in the water layers above 300m.

That's my best guess of what's happening now based on watching the sea ice rotation and Mercator ocean animations.

[Neven]

Here are September average temps:

- Second warmest on record Arctic-wide, third time above zero (after 2006 and 2016)
- Pacific record warmest by far (1.722 vs 1.215 in 1995)
- Canadian coldest since 1997

[Tor Bejnar]

third time above zero (after 2006 and 2016)

Hmmm, when I average the four quadrants (estimated) --  (-4.4 + .5 + .9 +1.8 )/4 -- I get -0.3
This is rather different from the +0.3 on the all-together-graph.  Where have I gone wrong? 

[Neven]

Arctic-wide should be -0.337. I get updates by mail when something changes in the timeseries. It looks like this:

Changed:
- 2018  -16.675  -15.676  -17.386  -10.064   -4.536    3.415    6.100    5.056 -99
- 9.999 -999.999 -999.999 -999.999
... into:
+ 2018  -16.675  -15.676  -17.386  -10.064   -4.536    3.415    6.100    5.056   -
+ 0.337 -999.999 -999.999 -999.999

I got confused by that +.

I'll modify the post above.

[FishOutofWater]

The cold and snow in western Canada combined with the heat in Alaska will reinforce the blocking pattern that we have seen in September. It still looks like a weak to moderate El Niño this winter so it could be very warm in Siberia for the winter - it's an El Niño thing.

If the CFSv2 is correct, and that's a big if, the cold anomaly in western Canada may move east as fall progresses into winter. Extremely stormy weather in California, Texas and the southern states of the U.S. can be expected in January through March. At the same time, the Arctic could be much warmer than normal, especially the Siberian side.

However the details work out odds favor another warm winter for Arctic sea ice.

[gerontocrat]

DMI North of 80 blips up.

(Yes, I know of it is somewhat limited value)

[bbr2314]

DMI North of 80 blips up.

(Yes, I know of it is somewhat limited value)

Year over year. That is some heat in the ATL! And the entire PAC. However, there is VERY cold water along the AK shoreline, and HB / Labrador are also much colder than 365 days ago.

The area N of Svalbard where the Gulf Stream has evidently been erupting has grown substantially.