The 2014 Melting Season

[ktonine]

Those models have been less than 50% correct on their 24 hours forecasts lately for where I live

how do you know?

so it is no surprise to me that the 5 to 10 day forecasts have been so far off for a tougher area to predict like the Arctic. I've long since stopped reading posts which focus on the long range forecasts.

https://yourlogicalfallacyis.com/composition-division

I am really tired of seeing L.V. and S.H. criticizing friv's posts.  Really tired.

Go back to Monday <a href="http://forum.arctic-sea-ice.net/index.php/topic,778.msg28064.html#msg28064"> ensemble forecasts</a> and tell me whether conditions are better or worse than reality.  Have the ensembles been correct?

Yes.

Don't read the posts.  Fine.  But STFU about it already.

[Bob Wallace]

There is a very simple solution.

Two threads.  One for discussing the present state of the ice and one for discussing what might happen out past the reliable limits of weather forecasting.

Nevin?

[Nightvid Cole]

Not true. The paper you cite is basing its conclusion over a period from June 15th - September 15th. It's certainly true that in late August and in September, clouds have a net warming effect. However, in June and July, they have a net cooling effect as is clearly seen by comparison on June and July SLP to temperature patterns and also the fact that high pressure tends to lead to faster PIOMAS volume drops in May and June.

So we still expect clear skies to accelerate the melting process at this time of year and cloudy skies to slow it down, as we saw in 2013.

I won't claim to have all the answers and I am sure there is more to be said on the subject. But I do cite more than one paper. Have you any papers to prove your last statement and that disproves mine? That would lead to an interesting discussion. 


Note that I don’t suggest that clear skies actually cause net cooling in summer months, but what I was pointing out is that there is less summer warming in clear skies over ice with high albedo in the Arctic than there is under cloudy skies.

Of course other factors will come into play as you can read in the following paper I quoted:
Clues to variability in Arctic minimum sea ice extent.  Jennifer A. Francis, Elias Hunter, Jeffrey R. Key and Xuanji Wang. Geophysical Research Letters 2005. http://onlinelibrary.wiley.com/doi/10.1029/2005GL024376/pdf

There are others:
Robert Stone. Variations in western Arctic temperatures in response to cloud radiative and synoptic-scale influences.   Journal of Geophysical Research Sept 27, 1997
He notes:
“even in April when the daily mean solar flux is large, clouds tend to warm rather than cool the surface affirming what Ambach (1974) referred to as the “radiation paradox”.

M. Nardino, A. Orsini, R. Pirazzini, F. Calzolari, T. Georgiadis and V. Levizzani. Cloud Radiative forcing and effects on local climate (2000)
They concluded:
“The main result of the present work is that during Arctic and Antarctic summer the net radiation increased with the cloud cover index. This phenomenon is the result of the asymmetry in the dependence of the net shortwave and longwave radiation on the radiative cloud properties and cloud amount”.

Michiel van den Broeke, Paul Smeets, Janneke Ettema, and Peter Kuipers Munneke. Journal of Geophysical Research (2008). “Surface radiation balance in the ablation zone of the west Greenland ice sheet”
We read:
“The total cloud effect is positive at all sites, i.e., clouds tend to increase Rnet at the surface. This is sometimes referred to as the “radiation paradox” [Ambach, 1974], and is a result of the high surface albedo, which limits the (negative) SW cloud effect so that the (positive) LW cloud effect dominates the total cloud effect”.

I don't get the impression that the paradox does not apply in certain months. Although, as I have allready noted, open water, melt ponds, thin ice etc will reduce albedo and then the effect does not apply.

Ok, k largo, you asked for it, you got it:

Cloud Radiative Forcing of the Arctic Surface: The Influence of Cloud Properties, Surface Albedo, and Solar Zenith Angle

...The annual cycle of Arctic CF reveals cloud-induced surface warming through most of the year and a short period of surface cooling in the middle of summer, when cloud shading effects overwhelm cloud greenhouse effects. The sensitivity of CFLW to cloud fraction is about 0.65 W m−2 per percent cloudiness. The sensitivity of CFSW to cloud fraction is a function of insolation and ranges over 0–1.0 W m−2 per percent cloudiness for the sun angles observed at SHEBA.

[Frivolousz21]

Why not cancel all weather modeling outside of 72 hours.  Quick someone call the ECWMF and NCEP offices and let them know the billions of dollars they have sunk into these super computer forecast models is all for naught.

90% verification on 120 hours out just doesn't cut it in the speculative hobby of watching the Summer sea ice melt.





The pattern change that has been modeled for 4-5 days now in the medium range.  Starts unfolding by the end of this day. And is easily visible on the models 24 hours out.

Honestly it feels sad to me that myself and other professionally educated mets have to defend modeling.  Because some long term patterns failed that torched the ice.

I see NO ONE has said a word about the model runs 2-3+ days ago that over pumped the ridge over Easter Siberia and had a weak PV over the entire arctic not coming to fruition?  Only when the models bust on a bad pattern has this issue caused so much distress.

This same discussion goes on over hundreds of message forums when snow bunnies don't get what they want. 

Are we tracking a scientific phenomenon or rooting for the ice to be destroyed?

Because if we are tracking a scientific happening limiting the tools we use to track it sounds ridiculous to me.

If we only had SMMR instead of AMSR2 would it not be good enuf?  Do you guys have any idea how bad the sea ice concentration validation is in Summer?

On it's best day it's as good or worse than the 5 day euro forecast validation. 

Should we ban posting those images as well they are equally unreliable.

Isn't that to much noise on the board. 


Enjoy the barbeque.

[Lord M Vader]

No, we shouldn't cancel all posts discussing the weather forecasts beyond 72 hours.

And I'm sorry if some people take my posts as criticism, certainly not my intention.. I think we all want some action now and get frustrated as the models have been so constantly unreliable the last weeks...

Started a new thread about long-range forecasts for 4-7 days if you think it is needed. If not, I have the deepest understanding if Neven & Co want to delete it!

[Frivolousz21]

Models are actually trending warmer in the last few days catching up to the surface albedo change.

Looks like in about 79 hours 2/3rds of the arctic basin will be above 0C.

[ChrisReynolds]

I don't get the impression that the paradox does not apply in certain months. Although, as I have allready noted, open water, melt ponds, thin ice etc will reduce albedo and then the effect does not apply.

Thanks for the clarification. For what it's worth I think you have made a good case.

Screen 2010, "The central role of diminishing sea ice in recent Arctic temperature amplification" figure 3 shows the impact of cloud cover changes from 1989 to 2008 in ERA. They find that cloud cover changes over the Arctic are largely a cooling influence.



To quote the legend of that graphic:

Figure 3 | Impacts of cloud-cover changes on the net surface radiation.
Mean net surface radiation (short-wave plus long-wave) over the 1989–2008
period under cloudy-sky (solid lines) and clear-sky (dotted lines) conditions.
Means are averaged around circles of latitude for winter (a), spring
(b), summer (c) and autumn (d). The fluxes are defined as positive in the
downward direction. Red shading indicates that the presence of cloud has a
net warming effect at the surface. Blue shading indicates that the presence of
cloud has a net cooling effect at the surface. The dashed lines show the
approximate edge of the Arctic basin. Symbols show latitudes where
increases (triangles) and decreases (crosses) in total cloud cover significant
at the 99% uncertainty level are found.

Summer (panel c) shows that clear sky (dotted lines) mean net surface radiation is higher than cloudy, except for north of 80 degN, where ice/ocean albedo feedback does not apply. This has long puzzled me, but it seems it is explainable by the issue raised by K Largo. Over the areas showing the strongest albedo feedback cloudy skies reduce the absorption of insolation, but over areas of high albedo in summer the infrared effect from clouds largely offsets any change in insolation.

Nightvid,

"Ok, k largo, you asked for it, you got it:"
No need to be so rude.

Further down from the abstract it is noted that: "Only in midsummer when the sun was highest in the sky did ]CFSW/]Ac surpass ]CFLW/]Ac , indicating that increases in summer cloudiness would cool the surface." This is because the shortwave cooling is dependent upon angle of incidence. SHEBA covered only a region of the Arctic Ocean in Beaufort/Chukchi in over one year. Further north towards the pole solar incidence angles will be lower, and the dominance of SW should be for a lesser part of the year.

SHEBA
http://data.eol.ucar.edu/codiac/projs?SHEBA

Shupe & Intrieri
http://journals.ametsoc.org/doi/pdf/10.1175/1520-0442(2004)017%3C0616%3ACRFOTA%3E2.0.CO%3B2

[ChrisReynolds]

There is a very simple solution.

Two threads.  One for discussing the present state of the ice and one for discussing what might happen out past the reliable limits of weather forecasting.

Nevin?

Bob,

I disagree. No more sticky threads. Things are rather quiet right now, conversation veers into tangents and some are casting about looking for the prospect of something exciting. When things get moving events will take more control of the discussions.

However if anyone wants to start a non-sticky thread they are always welcome to do so. Maybe if there is a consensus amongst the users of a thread that a person is derailing it a polite request could be made to that person to start their own thread. Personally I'm don't see King...'s posts as a problem, I just skip them.

But this is a hobby for all of us, isn't it? And hobbies should be enjoyable.

[Frivolousz21]

No, we shouldn't cancel all posts discussing the weather forecasts beyond 72 hours.

And I'm sorry if some people take my posts as criticism, certainly not my intention.. I think we all want some action now and get frustrated as the models have been so constantly unreliable the last weeks...

Started a new thread about long-range forecasts for 4-7 days if you think it is needed. If not, I have the deepest understanding if Neven & Co want to delete it!

FWIW:

Short range: 0-72 hours
Medium range:72-144 or 168 hours
long range: 168 hours+.

It's pretty much standard around that time frame. 

The weather it what it is. 

[orgu]

Meteorological models have big trouble predicting small scale features, below 40-50km (convective showers, tornadoes etc) will probably not appear at all. As for large scale features, they are very much predictable, like the Arctic split that seems to happen on Wednesday.

The 15mnt old EC12 also have this split. Must be 70-80% certain now.

And I do this as my daytime job.

[Lord M Vader]

Well, the latest EURO 12z run also have this HP hovering over the Arctic so yes, I think we can say that there will be a change in the weather pattern now in a few days from now. This will hopefully give us some more action in the drop of SIE. The question is with how much. Will we se the first 100 000 km² next week? Will be interesting to watch!

So far this June (1-13), we've only lost 600 000 km² of sea ice which is a quite small number. The last four years have all managed to see a drop of more than 2 Million km². With 17 days left this would mean we need to see an average daily drop of SIE by 80 000 km² to be on pair with 2010-2013 SIE loss in June. Impossible? No, if that would turn out to be the case we would wtill be behind 2010-2012 and about on pair with 2006. 2012 did see the worst June SIE so far by a total SIE drop by 2,4 Mn km². If the HP manage to hold its grip for the rest of the month that would still be virtually impossible and certainly require perfect melt conditions to melt out 1,8 Million km² (avg. 106 000 km² per day) to make June 2014 the worst June ever... June 2010 saw a sea ice loss by 1,5 Mn km² the last 17 days of June according to JAXA...

I think to achieve such a huge melt we need the big Russian heat wave to enter the Arctic basin where the ice is most vulnerable...

[Jim Hunt]

Jim, you might post a New comparison, if weather allows (and Your time!) in a week from now just to see what takes Place in only 1 week!? Would be highly intersting .

This from Friday 13th, since today things are rather cloudy. See above

[Neven]

Bob,

I disagree. No more sticky threads. Things are rather quiet right now, conversation veers into tangents and some are casting about looking for the prospect of something exciting. When things get moving events will take more control of the discussions.

However if anyone wants to start a non-sticky thread they are always welcome to do so. Maybe if there is a consensus amongst the users of a thread that a person is derailing it a polite request could be made to that person to start their own thread. Personally I'm don't see King...'s posts as a problem, I just skip them.

But this is a hobby for all of us, isn't it? And hobbies should be enjoyable.

Chris, thanks for wording my thoughts exactly (except that I do read all of friv's posts  ). I want to add that in principle I do not forbid and then close threads. A forum is a bit like a market of ideas, the good stuff stays on top, AND needs folks to be involved themselves if they want their thread to stay on or near the top.

I'm just interested in keeping the forum somewhat orderly, the atmosphere somewhat friendly (don't get angry too much, it's a waste of time and bad karma), so we can watch the ice together, preferably in not too many fragmented threads. If someone is being an a*****e, let me know. If you don't like certain comments, don't read them. And please, don't ask me to open separate threads.

---

I'm going to try and post a new ASI update on the blog tomorrow. Lots of info I will try to put in.

[RunningChristo]

That's great Jim! Thanks!

 The ice has clearly retreated further away from the shoreline/delta this year compared to 2013.

 The heat is ON up there, not only in Oslo were I ran a 10 K at Bislett (Golden League arena!) under a baking sun, realising that summer & icemelting might be a much more prefered combo than running & summer...

BTW, above 21 C at Kangerlussuaq today...just saying .

[Rubikscube]

Thank you very much Jim. I though it would be a little strange not having pics beyond 2012, but I didn't have enough fantasy to check out the other options . Will compare with 2012 and 2007 then.

Why not cancel all weather modeling outside of 72 hours.  Quick someone call the ECWMF and NCEP offices and let them know the billions of dollars they have sunk into these super computer forecast models is all for naught.

I appriciate that you are posting the forecasts friv and enjoy looking at them, most of us should be aware of the hazards that are part of long term forecasting so I don't see any reson to make a fuzz about forecasted trends not materializing. It also looks very likely that there will be masive ponding on the Pacific side in the week to come.

[Lord M Vader]

ChrisReynolds & Neven: great words!! We all wants things to happen, to see something exciting come true. All of you people who have posted pics of forecasts model are doing it nice. You know the feeling to wait for something exciting to happen and the disappointment when it doesn't come true? I'm very well aware about the forecast models limitations but it has been rather much now the last weeks with predicted heat waves that never have been materializing..

And yes, I agree with you about the tone. It's important and discussions should be enjoyable! If someone have felt annoyed, criticized and so on by my posts I do apologize for that.

Let us see if things are going to be more exciting now when it seems to be a change in the weather pattern close to the sunstice!

[Neven]

Thank you very much Jim. I though it would be a little strange not having pics beyond 2012, but I didn't have enough fantasy to check out the other options . Will compare with 2012 and 2007 then.

RC, there are links to all archive on the Uni Bremen Concentration Maps page on the ASIG.

[Nightvid Cole]

I guess it looks like at the pole and at very high Arctic latitudes > 85N, clouds have a net warming effect except for about 4 weeks before and after the summer solstice. At lower Arctic latitudes such as 75N, the period in which clouds have a net cooling effect is a bit longer, perhaps for six weeks before and after the solstice?

[Jmo]

Friv/...King. I like your posts. keeps things interesting. I read all comments daily.
cheers.

[LRC1962]

We are in for an ice age. @ FIFA World Cup Costa Rica 3 Uruguay 1. Since CR was supposed be by far the worst in that group. Let us just say OOOOOuch on the part of U

[helorime]

It's pretty warm in Alert too. 

ALERT, NUNAVUT, CANADA

    Weather report as of 173 minutes ago (23:00 UTC):
   The wind was blowing at a speed of 7.7 meters per second (17.3 miles per hour), with gusts to 11.8 meters per second (26.5 miles per hour), from Southwest in Alert, Canada. The temperature was 6 degrees Celsius (43 degrees Fahrenheit)

[Frivolousz21]

It's pretty warm in Alert too. 

ALERT, NUNAVUT, CANADA

    Weather report as of 173 minutes ago (23:00 UTC):
   The wind was blowing at a speed of 7.7 meters per second (17.3 miles per hour), with gusts to 11.8 meters per second (26.5 miles per hour), from Southwest in Alert, Canada. The temperature was 6 degrees Celsius (43 degrees Fahrenheit)

It is currently 8C with winds blowing SW 34 gust 59 km/h.


Damn.

[greatdying2]

http://weather.gc.ca/forecast/trends_graph_e.html?ylt&unit=m

Looks like Alert got hot, windy, and dry starting at about 5 p.m. local time this evening.

[Neven]

ASI 2014 update 3 is up: here comes the Sun (again)

Latest ECMWF forecast:



Dominating highs again, but no dipole.

Temps are also projected to go up again, but this time for real?



I'm ruling out a new record, but with sufficient high pressure and temps 2014 could be a top 3 contender.

[jdallen]

ASI 2014 update 3 is up: here comes the Sun (again)
<snippage>

I'm ruling out a new record, but with sufficient high pressure and temps 2014 could be a top 3 contender.

I'm pretty confident we beat 2007, and beating 2012 is a 50-50 prospect. We'll see how the next fcouple of weeks go.

[Lord M Vader]

Neven: how did the synoptic situation looked like in 2007 and 2010-2012 for July? After all, the weather pattern in July is of vital art if we are about to see some rapid changes in the SIE. Also of great importance is the ice thickness compared to 2007 and 2010-2012.

The latest GFS 6z run didn't put the HP over the Arctic to be as strong as earlier runs. The EURO 00z run had a strong HP covering a big part of the Arctic basin. The question then is how the ensembles look like and if the GFS 6z run should be viewed as an outlier?

One interesting feature that ASLR have posted today in the El Niño thread is that the OHC according to NOAA has dropped sharply the last time.

[Rubikscube]

This is how 14. June 2014 compare to the same dates in 2007 and 2012 (be aware that the 2007 pic is AMSR-E, 2012 is SSMIS/F18, which includes an ugly grey rim along the coast, while 2014 is AMSR-2).

2012


2007


2014 appears to be lagging far behind those years both when it comes to melt in the Beaufort and when it comes to ponding/divergence on the Pacific side in general. However, the current area of open water in ESS isn't matched by neither 2012 or 2007, and the huuuge area of positive anomaly in Kara (2012) indicates that the June 2012 SIA cliff is inflated by unsignificant melt (in the sense that September minimum the same year is not affected) and far from impossible to catch up with later in the summer. Also note the apparent lack of Farm export.

[iceman]

Two threads.  One for discussing the present state of the ice and one for discussing what might happen out past the reliable limits of weather forecasting.

+1
If nothing else, this thread is certainly heating up.

EDIT: retracted after reading Neven's response to Chris R above.

[Lord M Vader]

As it seems to finally be warmer in the Arctic I think it is appropriate to ask what the dates are as the North East Passage have become open? Given the favorable melt conditions that are forecasted to come in combo with thin ice could open up the Passage very early.

//LMV

[Frivolousz21]

Toasty.

[Neven]

I have added the SLP pattern map for June 7th-12th on the SLP Patterns page:



Except for 2009, no year comes close to this set-up.

2012 had the ideal pattern:

[Frivolousz21]

The Euro and GFS ensemble means are incredibly bad.

No end in sight to the ridging/torching.

[Frivolousz21]

The potential for record losses during June 20th-30th continues to grow.

We haven't even talked about how had the Laptev-Kara region gets torched and flushed during this.

[sydb]

I am a daily reader of this site, though I don't comment much as I don't have the specialist knowledge many other contributors have. However, I really enjoy Friv's posts and hope you continue them. Sometimes they remind me of the woman who used to appear in Frankie Howard's "Up Pompeii" in the 70s on the BBC. She always cried "Woe, woe, and thrice woe!" before predicting disaster would befall Pompeii.

Of course, all the other characters ignored her, treating her as a joke. But the audience all knew she was right, which greatly added to the humour. I consider that Friv's "Woe, woe, and thrice woe!" is very well justified in the long term and we may not have to wait long for it to come true.

It is very difficult to call crashes correctly, even when they are obviously coming. I predicted the financial crash in 2005, but had to wait 2 years to be proved right. At least I didn't buy any of Greenspan's "toxic waste," so I did get the last laugh eventually.

[Csnavywx]

If this thing develops into an omega or rex-type block like some of these runs are suggesting, it will become quite difficult to dislodge.

[Michael Hauber]

Forecasts at 5-7 days can be ok - but often wrong in the details even though the large scale set up may be roughly correct.  And it is often the details that matter.  For a local weather watcher its whether a storm system is overhead or a hundred k away.  Or at this time of year whether a heat plume from subtropical Asia makes it 3000k to reach the Arctic, or only 2500k to fall short.

I think the big high in the Beaufort looks very likely, but whether it pulls quite as much heat in as ECMWF thinks it might (much more than GFS latest run) is uncertain and depends on how well it connects with heat being drawn from USA north through Canada.  This will condition the Arctic well for further melt, but at the moment the Beaufort is behind a bit on melt and I think it needs a bit of softening before we see any meaningful extent reduction.  Although I expect we may start to see the June cliff rear its head with some significant melt ponding in this area.  Later in the 7 day forecast A huge and intense tongue of heat off the Eurosian continent approaches the Arctic, and models seem to think only the edge will impact the Kara/Laptev sea.  A little further away and nothing will happen in the Arctic, a little further into the Arctic and the results could be spectacular.  Other than the potential for this heat blast there doesn't look to be a lot of reason to expect significant melt in the currently weak Laptev area.

Seemingly unnoticed on this forum Baffin has been motoring along for a couple weeks, and Hudson is starting to get into gear as well, with well above average loss in both areas according to CT regionals.  Forecasts show continuing strong heat in both areas.  Surprising after the polar vortex winter - but I think Baffin may have missed the worst of the polar vortex.  And it seems that early summer has been hot enough in Hudson that thicker ice there only delayed the faster melt.

[Jim Hunt]

Seemingly unnoticed on this forum Baffin has been motoring along for a couple weeks, and Hudson is starting to get into gear as well, with well above average loss in both areas according to CT regionals.

Thanks to Wipneus this forum has advance warning of well above average loss in CT regionals. See for example:

http://forum.arctic-sea-ice.net/index.php/topic,382.msg28172.html#msg28172

[Jim Hunt]

A bit cloudy today, but you can still make out the fractures that have appeared in the East Siberian and Laptev Seas, and across the northern end of the Nares Strait:

http://GreatWhiteCon.info/resources/arctic-sea-ice-images/summer-2014-images/#ESS

[jdallen]

There has been some bickering over forecasts. Let's shorten the timeframe.

The next 12-48 hours shows ramping of near shore temperatures to 20+ degree (!!!) anomalies along the Kara and Laptev, with bookend 10+ degree anomalies along the Beaufort from the CAA to the Bering.

Baffin and Hudson Bay also look to be getting hammered.  Got your parachutes ready for some base jumping?

[jdallen]

Codacil: extensive areas of rain look to be forecast for the Kara, some what less for the Laptev and Beaufort.  They may cause some striking changes in albedo, as well as savage the ice.

[BornFromTheVoid]

Looking at the ECM for the next 5 days, it seems reasonable to expect average to slightly above average losses this week.
From today onward, Hudson Bay (1.15 million km2 remaining) sees some mild air take hold, which may result in an average 50k/day loss for the region. Baffin sea (750k remaining) is in a similar state, and could see losses averaging around 25k/day over the next 5 days.

850hPa temp anomalies today


+5 days


The Eurasian coastline, especially Kara and Laptev seas, look like seeing bouts of warm air over the coming 5 days, but it's hard to guess just how much melt that will cause. But it's likely that it will contribute to a few >100k daily losses for the whole Arctic between now and the weekend.

+1 day


+4 days

[F.Tnioli]

I'm pretty confident we beat 2007, and beating 2012 is a 50-50 prospect. We'll see how the next fcouple of weeks go.

And you're not alone. I've said in this very topic few weeks ago, iirc, that i expect the minimum SIA to be 2012 plus-minus ~500k this year. And i pray for it not to go below that, too.

Meanwhile, El-Nino signs get almost certain. It made big news, such as here ( http://www.theguardian.com/environment/2014/jun/11/-sp-el-nino-weather-2014 ), and there are some gents saying it's already started, such as this one ( http://www.aljazeera.com/weather/2014/06/el-nino-already-here-201461585250418750.html ). It was already mentioned in this topic, more than once, what this means for the minimum, following freeze season and 2015.

[Lord M Vader]

There are discussions whether there is a possibility to beat 2012. I looked at my earlier post #910 where I listed the numbers of SIE losses in July and August for the years 2003-2013. The three most significant SIE losses during July respectively August were:

July: -3,1 Mn km2 (2007); -2,9 Mn km2 (2009) and -2,85 Mn km2 (2012).

August: -2,5 Mn km2 (2012); -2,15 km2 (2008) and -2,0 Mn km2 (2004).

Whereas the SIE drop is about the same magnitude in size for July the numbers for August differs great.

Considering that we'll end up with a SIE about 9,4 Mn km2 per June 30. If we consider the ice melt to have the following numbers for July and August: -2,9 Mn km2 in July and -2,1 Mn km2 in August we would have a SIE of 4,4 Mn km2 per August 31. If we add about 400K drop in september we would end up at a minimum peaking at 4,0 Mn km2.

As we right now are behind 2012 in extent and 9,4 Mn km2 seems reasonable for June 30 a "perfect" melt would be -3,15 Mn km2 in July followed by a drop of -2,45 in August. Then we would have a SIE at 3,8 Mn km2 per August 31. A drop of 400 K would almost bring us down to 2012.

My conclusion: no chance that we'll beat 2012 unless there will be "perfect" melt conditions for now and on, especially in August. August 2012 presented almost perfect conditions with a GAC. I don't expect this to happen this year. Likely there is a 50-50 shot that we can beat 2007. Most realistic is that we get a minimum around 4 Mn km2. But: never say never!:)

Finally: the temps have almost reached zero now according to DMI. That was about time!! And a question for the big aces here on ASIF: how was the synoptic situation in Arctic in the summers of 1990 & 1991 which according to DMI and my subjective judgement were the two warmest summers for the POR since 1958? If my memory isn't entirely wrong we had a huge positive AO these two years, at least during the winters...

[ChrisReynolds]

I tend to agree with you Vader.

I see very little chance of 2012 being matched, let alone beaten.

Between 7 June and 18 June CT Area anomalies in 2012 dropped 2.2 million kmsq, the largest June Cliff so far. Yet this year we have so far only an suggestion over the last few days that the 2014 cliff may be starting. 2010's June cliff was a loss of 1 million from about 8 June to 26 June, less of a precipitous drop when compared with 2012. So we shouldn't consider 18 June as a deadline. However the cliff seems to be due to melt pond spread and the later this happens the less time for preconditioning.

As Crandles pointed out to me, in a SIPN presentation Blanchard-Wigglesworth revealed results showing that when ice is thinned by 1m at the start of the melt season (to simulate future years) PIOMAS loses almost all of its extent by early July, what follows is a reduced level of loss compared to the past baseline. This is similar to what we see in PIOMAS anomalies, where after 2010 (a step thinning) there is massive loss of volume in spring, but after the solstice (21 June) losses are less than or similar to losses in the baseline average period (1980 to 1999). I don't think that this is a peculiarity of PIOMAS that is not reflected in reality because after 2010 NSIDC June losses show an increase.

The spring loss in PIOMAS is going on, it also happened in 2013. But in 2013 the spring volume loss was not as great as in the other three post 2010 years (2010: -10.432, 2011: -9.582, 2012: -10.973, 2013: -8.989 - 1 May to 1 July loss of volume). May's volume loss places 2014 in the 2013 camp, not the 2010 to 2012 camp.

So taking the spring volume loss, and CT Area cliff indicating preconditioning of the ice, I think the window of action in the early summer has probably been missed.

My 10 June submission to SIPN was based on September average NSIDC Extent and was from 4.62 to 3.48M kmsq. I'm standing by this range for now (after all it's not yet been formally published!) but think the probability has shifted to the high side. I expect 2014 to be in the range 4.06M kmsq to something over 4.62M kmsq, but not as high as 2013.

[Csnavywx]

Agree that 2012 is too far out of reach at this point. Even pulling a 2007 melt might be a stretch unless the current pattern sticks around for a couple of weeks (which it might).

My main concern this year is with the MYI on the Pacific side which seems to be vulnerable to a near total melt-out if this pattern sticks around, which would be quite detrimental to the quality of the remaining MYI pack.

[Nightvid Cole]

I'm getting really sick and tired of this cloudy weather that won't let us see the CAB right now on MODIS   

[helorime]

It is way too early to determine what the outcome of the entire season will be.  2007 had a much later June cliff than 2012 did, 2011 had a much more steady drop, yet as late as late July all three of those years were at almost the exact same place in terms of extent.  Even in area in late July the differences were not huge.  It was the much bigger drop in August that made the difference in 2012, and the lack of that in 2013.

[Frivolousz21]

There is a lot of time left. 


We saw how far 2013 fell with hardly any bad weather for the ice.

This pattern is brutal and it's early.

2013 had great ice retention weather.  We are about to see the complete opposite during peak insolation.

[Frivolousz21]

12z GFS think about the massive difference in visible light energy this year during late June versus 2013.

[Frivolousz21]

The 12z Euro destroys the CAB