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Messages - Sterks

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Arctic sea ice / Re: The 2017/2018 freezing season
« on: March 16, 2018, 05:11:08 PM »
the onset of the 2018 melting season.
Hear hear

Arctic sea ice / Re: The 2017/2018 freezing season
« on: March 16, 2018, 05:02:50 PM »
Why [...] just opine.

Michael is generally good with detail and checks work thoroughly, but there have been one or two minor errors here and there

Arctic sea ice / Re: The 2017/2018 freezing season
« on: March 05, 2018, 12:28:08 AM »
Forgot to post how I have divided the Arctic in four sectors:
Interesting to note (surely not the first) that the two sectors with clear positive trends are the ones named after the Pac and Atl oceans, while the two sectors with no clear trend are basically the continental ones.

Arctic sea ice / Re: The 2017/2018 freezing season
« on: March 02, 2018, 12:24:47 PM »
Thick snow layer self-preserves in Spring just by the same principle for which thin sea ice self-destructs in Summer.

We'll see how warm Spring comes to mid-high latitudes. The key for the Arctic is how much snow remains in May, in places like Canada and Siberia.

Arctic sea ice / Re: The 2017/2018 freezing season
« on: February 27, 2018, 03:43:28 PM »
To finish off what I hope reinforces all that A-Team said about snow.

The Polar Science Center say in their PIOMAS updates that on average  16,400 cubic kilometres ice (= 16,400 GT) are melted during the brief Arctic summer.
In contrast, average maximum Northern Hemisphere (excluding mountains) snow water equivalent is about 2,800 Gigatons (GT) (= km3). This year it may max out at about 3,300 GT, a very unusual additional 500 GT. (Last graph in )

Only a small fraction of that 500 GT can have an impact on the Arctic, i.e. a fraction of about 3% of ice melted every summer in the Arctic. A 0.3 degree rise in Arctic temperatures over the last 5(?) years would surely do for any impacts of increased snowfall in Quebec?

Not sure that I understand you, gerontocrat, but the impact of NH snow on melting seasons has been really well established these past seasons, just see Rob Dekker's model. More important than mass here is the area that snow persistently covers in a cold Spring (or stops covering too soon in a warm Spring) in the NH, which increases (decreases) the normal NH albedo, which ends up being a factor muting or enhancing the sea ice melting season. The volume is not so important

But I may be missing the real topic here...

Edit. I was lazy. Reding A-Teams post I suspect now why you were comparing ice volume with snow volume at the NH level.
Still let us keep a good eye on how NH snow cover starts to decline toward May or so. Last year vast extensions of Asia stayed covered with snow well into June because Spring was really late, and that "quenched" the otherwise hot season that was coming (may-be)

Arctic sea ice / Re: Global sea ice area and extent data
« on: January 29, 2018, 10:50:42 PM »
I thought I would step back and have a look at global annual averages over the last few years using JAXA data as relief from the microscope of daily changes.

I think the graph below is OK. Note the dips around 2007 and 2012 (Arctic Sea Ice major losses) and the 2015 high - Antarctic record highs. The overall trend is, obviously - down.
Not so obviously, when you cut the plot about somewhere 2015 and was, "obviously", up.
Unsettled I'd say, which is the same as no freaking idea.

Arctic sea ice / Re: The 2017/2018 freezing season
« on: December 04, 2017, 05:51:03 PM »
Four equal quadrants, I see. (Forgive me if you don't see them as being equal: I'm not wearing my glasses at the moment, and it might be relevant that I am an American.)
 :D :-\ ::)

The American quadrant is the biggest!

Hmm, maybe I should make them equal in size, but I'm not sure how that looks geographically (especially Pacific)...
Why not making the Pacific region larger, even if it overlaps other regions. When I think on the Pacific side (and I believe many people here too) I think on a much broader region including most of the Beaufort sea, reaching Amundsen Gulf on one side, and taking on the other side part of the ESS as well (almost reaching the New Siberian Islands).
In other words 120W to 150E,
around the pole
north pole

Arctic sea ice / Re: The 2017/2018 freezing season
« on: December 01, 2017, 03:04:03 PM »
Beaufort Gyre forecast to become re-established in early December along with Fram export. (From Arctic16.gif of NOAA REB plots at ESRL; speeds shown in m/s, direction with arrows.)

Interesting observation.
Didn't last year (winter) characterize by an almost total lack of Beaufort Gyre due to the train of cyclones coming from the Atlantic, imposing a general cyclonic circulation affecting the ice drift as well?...
In this sense, we may be heading for a more "normal" winter. Once the Chukchi sea freezes, of course.

Arctic sea ice / Re: The 2017/2018 freezing season
« on: November 18, 2017, 11:55:36 PM »
 Look at those isobars. Extremely windy these next days in the Central Arctic, very cold in Siberia, not really in the Atlantic sidem

Arctic sea ice / Re: 2017 sea ice area and extent data
« on: November 18, 2017, 02:15:50 PM »
Thank you for this work, A-Team. So in the Arctic Ocean proper, there is a distinct probability of a repeat of last year lack of winter power, or something similar, that's interesting. A (slightly) positive anomaly of NH snow seems to be accompanying again, but how that snow retreats in spring, that is really unpredictable.

Arctic sea ice / Re: The 2017/2018 freezing season
« on: November 14, 2017, 02:45:02 PM »
Quite a change ... one of our long-time resources for sea ice thickness has been replaced. The ice is markedly thinner in the new products; whether it is any more accurate is questionable. Still, the forecasts give some idea what is coming.

Unless they have improved something very recently, this model is absolutely unreliable, it shows such a thin ice, (especially in summer), that nothing else out there supports or aligns with, whether PIOMAS, Cryosat, SMOS, or just what we have been seeing from the buoys or the Healy.

Expect however some extremely avid followers of this Glb thing in summer. A pity, the Acnfs of the last two or three years did not behave bad at all (for ice thickness; for ocean in general dont know, but probably this is an improvement, otherwise what's the point).

Arctic sea ice / Re: The 2017/2018 freezing season
« on: November 04, 2017, 01:26:18 PM »
I have been reading the 2017 melt season for a couple months. That was easy to follow, because i just had to read the numbers. But the freezing season is harder to get. What is the problem ?  Is the arctic not doing what it should be doing at this time. The melting season stoped somewhere in september, if i'm correct. And now we are in november. Is it not adding extra ice every day ?
Just boring. No cataclysm in sight

Arctic sea ice / Re: The 2017/2018 freezing season
« on: October 23, 2017, 12:05:17 PM »
Given the very poor start that 2017 had (the worst ever), I think it's accurate to say that 2017 has rebounded nicely, and better than almost anyone expected.

I agree with this statement. A rebound that most probably places the <1 mkm2 event beyond 2020.

Arctic sea ice / Re: The 2017/2018 freezing season
« on: October 14, 2017, 08:25:53 PM »
Therefore, expect a normal or above-normal ice extent growth.

Arctic sea ice / Re: 2017 sea ice area and extent data
« on: October 12, 2017, 02:09:36 PM »
Why speculate when the forecast is just a click away?
It's really cool but how do we quantify forecasted area or extent? Perhaps you have a tool for that?
Thanks for this work btw

Arctic sea ice / Re: 2017 sea ice area and extent data
« on: October 12, 2017, 01:17:06 PM »
JAXA Sea Ice Extent:
Jim, your post shows the graph updated only until Oct 6.

Arctic sea ice / Re: The 2017 melting season
« on: October 09, 2017, 04:06:38 PM »
Amazing work, thank you.
I am intrigued not only by the blob of recent summers, warm yet cooler than 2012 and prior, but by some diagonals that appear crossing many years and survive even the strongest filtering. Difficult to ascertain what they could mean.

Arctic sea ice / Re: The 2017 melting season
« on: October 09, 2017, 09:16:26 AM »
The ranking for July was 29th. Preceded by 16th for May and 15th for June. The (co)incidence of this cold summer with the thin ice out of the previous winter is remarkable, and final extent just reflects so.
Great graph, Zach.

Arctic sea ice / Re: The 2017/2018 freezing season
« on: September 30, 2017, 12:17:57 PM »
Thanks A Team.

I remember asking about strange ice thicknesses near the ice edge in the Beaufort earlier in the month. So it was a normalisation glitch. Comparing these before and after glitch still images attached, the glitch was especially pronounced in the magenta highlighted areas, with thicknesses stepping from dark red to blue.

But after Sept 16th, the thicknesses do look on a par with what you would expect this year - before that date, thicknesses are not trustworthy.
The ice model was forced to assimilate a PIOMAS update. (?)

Arctic sea ice / Re: The 2017/2018 freezing season
« on: September 26, 2017, 11:07:04 PM »
Yes, Neven, removable, OT, but there was a Jai Mitchell's off topic just above mine to which I reacted. As I would have, if the headline he was bringing had been ""the Arctic ice is in the best shape in years, and getting better".
All the same, letting politics and/or interests one side or other twist the truth or plainly lie.
Back to topic.

Arctic sea ice / Re: The 2017/2018 freezing season
« on: September 26, 2017, 08:55:50 AM »
Starting to get less and less interested on stories that fall on the side of greatest drama. Like a bell I have been hearing for years and is not alarming or thrilling anymore, but a bit bothering.
What about "Volume rebounds 2000 km3 from spring, but statisticaly continues its downward trend just as area and extent do"
Maybe  "A relatively cold spring and summer at high latitudes helps the Arctic end in slightly better conditions than 2016 and 2015"
Or perhaps "The least drama side (or cold-facts side) of several scientists expecting seasonally ice-free Arctic by somewhere mid-century, while not dramatic, may have some base after all"
The last one is an inconvenient statement for some with apocalyptic thoughts who want to see the blue Arctic in their lifetimes  ;) preferably next year.

Really? Please tell us how you measure "excellence of weakness" and where this was "proven". Air temperature is only one of many components contributing to refreeze season outcome and FDD is only a crude summary of it. The days of just eyeballing the Arctic are long gone.

Clinging to the simplicity of rough measures does not add value because there's no extra compute time in replacing them with something much more refined. That's why FDD and 80ºN are little used in climate science modeling of the Arctic Ocean. They don't have the spatial or temporal resolution commensurate with other model components, mooting precision improvements there and so introducing gratuitous error.

In fact I can't prove such excellence. I just meant to note that the FDD of 2015 and 2016 were extremely anomalous, and it showed in 2016 and 2017 state of ice prior to summer, nothing else.
Lately I tend to be overly sarcastic on occasions, my excuses. Actually my opinion is that your work with ESRL data is really excellent, I wish I had the time and resources to get hands-on with Panoply and produce material for the forum as well.
So I am just another guy with an opinion, and I'll try to stay quiet :)

There is no coverage of previous years so what best provides historical context for a 'weak freezing season'?
Imho a map over the Arctic Basin of freezing-degree-days should show which freezing seasons are relatively weak, and in which regions. That data exists for previous years as we have their temperature maps.
The 80N FDD, a simple scalar per day, has proven an excellent indicator of weakness of the past two freezing seasons.That and the amount of Fram export can help assess the state of the ice in May (plus some thickness and ice age products to know the ice distribution, and we have had those since a long time ago. Pre-Panoply times)

Arctic sea ice / Re: The 2017 melting season
« on: September 16, 2017, 01:30:37 PM »
5days out is unreliable, but as it's quiet here - GFS is predicting 978hpa
The ECMWF has it a little lower but in about the same position for the 20th. I think that it has been noted to be pretty reliable for a few days out. Not my cup of tea, reading these charts, but this looks like the makings for a strong gradient setup.
Le coup de grâce to this thread

Arctic sea ice / Re: IJIS
« on: September 14, 2017, 02:55:25 PM »
Some years like 2016 had areas of below 15% slush but it wasn't really ice free. I'd prefer to count end-September extent to rank annual minimums
That goes both ways. Hard to consider some >15% areas of last year as not ice free for practical purposes, like negligible volume aggregated, avaliable heat for release, and even apt for navigation

Arctic sea ice / Re: NSIDC 2017 Arctic SIE September average: August poll
« on: September 12, 2017, 11:34:46 PM »
Unless there is an unexpected fast refreezing, like last year but even faster, September extent can't be above 5 million km2, something is wrong in your assumptions (two things I'd say).

Arctic sea ice / Re: 2017 sea ice area and extent data
« on: September 09, 2017, 11:52:58 AM »
And minimum extent any day now. The forecast turns really cold for the Central Arctic and the Pacific side.

Arctic sea ice / Re: Latest PIOMAS update (September update)
« on: September 06, 2017, 11:09:04 PM »
A comparison of Piomas to ice thickness at the new NOAA-RASM-ESRL-PSD site ( shown). It's not clear that a netCDF file exists for Piomas thickness, they seem still into fortran mode. This makes quantitative comparisons fairly difficult. Maybe that's the idea (?).
No. The idea in academia is don't break what it works. Be it fortran 77 using a non standard grid. And that there is one or two digits less available in the amount for grads and post docs to refactor code compared to industry or big institutions.

Arctic sea ice / Re: The 2017 melting season
« on: September 06, 2017, 12:31:23 AM »
no net refreezing growth anywhere

Yes, which is starting to be harder to reconcile with observational products, areas shooting up by some 100k's in a few days and things like that.
The net melt map of ESRL shows positive melt indeed, but of really small magnitude (order of milimeters/day rather than cm in some places) in growingly extense area of the Arctic. It also shows an unfortunate selection of minimum melt / minimum freeze color: white for both. Therefore we cannot know if indeed there is melt everywhere or, finally, refreeze is forecasted somewherein the white areas. I cannot process the nc myself, no way to know. :(

Arctic sea ice / Re: The 2017 melting season
« on: September 04, 2017, 06:37:35 PM »
i give it another 5-10 days to admit defeat LOL
The strong warmer winds from the Atlantic are more certain to materialize, so indeed I would not admit defeat in another 5 - 10 days, despite the ice pack to start closing in the most broken areas.
Hey, it's been cold up there!

This is how hycoms sees ice drift in five days, conditions lasting for two or three days.

Arctic sea ice / Re: Home brew AMSR2 extent & area calculation
« on: September 03, 2017, 10:30:06 PM »
No.... The ESRL products did not show anything particularly indicative of refreezing for today.

Oh wait there was the helloutta snowing and -6C or lower in many areas of the CAB in their forecast, but I guess those were mistaken

Arctic sea ice / Re: The 2017 melting season
« on: September 03, 2017, 12:45:11 PM »
Perhaps some got caught up in day to day details and misleading forecasts ---myself about a week ago---.
It is safe to say, no matter if the minimum is today or by end of the month, that the amount of ice, and more importantly the spatial distribution of it, is similar to last year's end of season, with more and thicker ice in the Atlantic side, and sparser and thinner ice in the Pacific side, although the way the ice pack has reached to it is really different. There will be ---most probably--- more volume, extent and area at minimum, but the differences will not be that significant. If the Arctic experiences another winter as 2015/2016 or 2016/2017, it will have to dodge another bullet in 2018. If.
Really interested on how this winter is going to be.

Arctic sea ice / Re: The 2017 melting season
« on: September 03, 2017, 09:15:18 AM »
Really, that nobody stands up to you and your arrogance...
I'd rather you take this back. It's a science forum, not a personality forum.
I wish I could do what A-Team calls for, I lack the computing power, the technical know-how, the time, and mostly the discipline to acquire what I lack. But I still commend it. And I do my utmost best to avoid ad-hominem statements.
I think you are right (and the moderator). I have removed the post, I dislike ad-hominems as well.
I apologize for that.

Arctic sea ice / Re: The 2017 melting season
« on: August 31, 2017, 07:41:40 PM »
A. Snow does not constitute refreezing, even though it may somewhat affect area readings.
B. -2 and even -6 deg temps do not generally freeze seawater, though they refreeze meltponds (again affecting area readings).
I get it. I just say, I thought I saw a significant cooling in the ESRL forecast for a vast region of the pack, comprising not only North of 80N but also the pacific-side edge, and it looked more agreeable with freezing than melting, that's all. I understand bottom melt will continue at places, but if cold temperatures dominate, even that can abate earlier than expected... Or coexist with ocean surface freezing, briefly

Arctic sea ice / Re: The 2017 melting season
« on: August 31, 2017, 07:29:47 PM »
Right. So who's we?  In my opinion
You should write the chief scientist there and tell them of the big mistake in their model.
No, I don't find anything essentially mistaken in their model, don't misunderstand my words.
Let's not make a ball effect of misunderstandings. I don't agree with some of what you said, not with what the maps indicate. You being whatever collectivity or an individual. Ok? That's all.

Arctic sea ice / Re: The 2017 melting season
« on: August 31, 2017, 03:02:11 PM »
Right, there is net melt everywhere through Sept 4th. As far as we know, the freezing season has not started. There'll be some overlap in a few weeks though.
Right. So who's we?
In my opinion, the ESRL graphs show as many symptoms of continued melting as already overlapping symptoms of refreezing in very extensive areas of the Arctic. These snows shown above come accompanied of temperatures below -3ºC, sometimes below -6ºC, also shown in the same web page. Snow is made of frozen water, and with these temperatures, it may remain frozen, as far as I know.
Some locations near the Beaufort "appendix" show SSTs close to -2C, and some early signs of expansion (not dispersion) of the pack, coexisting with other areas where the water heat excess is melting the ice in a matter of days.

Arctic sea ice / Re: The 2017 freezing season
« on: August 30, 2017, 09:11:39 AM »
Significant cooling and snowing over the CAB toward the Beaufort side in the next days. The snow models of ESRL and GFS:
Not sure how to bring these animations here out of the noaa page.
The winds seem to keep pushing the ice from the South at Laptev and ESS from this model.

Arctic sea ice / Re: 2017 sea ice area and extent data
« on: August 29, 2017, 07:33:12 PM »
Actually the inverted dipole is getting in a location to spread the pack even more (the low is creeping into the Central Arctic) with colder, much colder temperatures over Beaufort Chukchi and the adjacent portion of the CAB. However, strong warmer winds over Laptev and ESS are keeping melt up in these areas, as Wipneus map over AMSR2 thread shows.
What may be happening is that NSIDC lower resolution picks the first effect but not the second for extent. UH extent has kept falling steadily, the pack is very broken.
Relative equilibrium situation in regards to extent, but since UH area keeps falling, extent is candidate to further loses later (I guess, weather dependent).

Arctic sea ice / Re: The 2017 freezing season
« on: August 28, 2017, 07:47:42 PM »
The inverted dipole that has seized the Arctic will be pulling air from the Atlantic/Asia and compacting the ice North of Barents, so I would expect more extent loses. But the winds across the Arctic become Northernlies at the broken ice edge of the Pacific side, where one would expect those sudden refreezes like last year would happen first. So who knows.

Arctic sea ice / Re: The 2017 freezing season
« on: August 28, 2017, 02:00:57 PM »
Hi Sterks

This link will get you regular updates of their current location:

Thank you!

Arctic sea ice / Re: The 2017 freezing season
« on: August 27, 2017, 08:43:03 PM »
Thanks Niall. I read in the dedicated ASIF thread that they are approaching the pack through the Beaufort bite, and if this is 80 N , they are just at the edge of broken ice.
Is there a web where they are posting regular updates and their location?

Arctic sea ice / Re: The 2017 melting season
« on: August 26, 2017, 03:16:55 PM »
Sterks: check the EPS daily average, not the 1-5 day period. However, the "Garlic Press" isn't as pronounced as it was a few days ago.
Thank you :)
The multiple averaging of the EPS across simulations and over 5 days must smear the isobars through CAA. These are clear when looking at the daily ECMWF.

Arctic sea ice / Re: The 2017 melting season
« on: August 26, 2017, 01:51:06 AM »
That's great A-Team.
The only doubt I have is how DMI satellite-based SST maps can display above-zero SSTs under the ice (notably at the Beaufort appendix).
But I assume that it is normal noise, and also may be caused by the current thinness and sparseness of ice over there.

Arctic sea ice / Re: The 2017 melting season
« on: August 25, 2017, 11:46:44 PM »
Plenty of compacting winds for the next five days, warm from the Atlantic too, that will bring losses of extent for the rest of August.
I don't see a garlic press happening though from the Hycom drift forecasts. But at any rate the Hycom forecasts are not at its height in reliability, momentarily

Arctic sea ice / Re: The 2017 melting season
« on: August 25, 2017, 06:13:15 PM »
total melting has the limitation of being cut off at 0.35 cm/day,  the computed melt is much higher at many ice edge locations.
That is a good one to write them about ... questions are encouraged.

It turns out that there is a tab dedicated to thickness change (snow and ice), and the scale does not cut off the different melts (bottom, lateral, top). In this case I cropped the right-side palette scales to fit the screenshot into the 700x700, but they were identical to the scale for the left-upper melt map (ice bottom melting).
In fact, bottom melt is forecasted of the order of 1 cm/day and up to 2 cm/day in the very edge of the pack.
It surprises me how much bottom melt varies day to day, and how dependent it is of the changing winds in the next days.
And it surprises me the almost absence of noticeable lateral melt in the model forecasts. Nothing going on inside the "soup"? Even with these temperatures I would have expected to see something under the white bin, of -0.3 /day (funny that in the total melt graph, the researcher sets up an Upper cut-off of close to 0.3/day, if we combine this bottom melt map with the total melt map, we almost get the complete picture of it)
As soon as it gets "quiet", bottom melt is reduced, that is nicely reflected in the forecast.
Can we consider the "2017 Surface Melting Season" finished?

Arctic sea ice / Re: The 2017 melting season
« on: August 23, 2017, 11:00:19 PM »
Since the ESRL postprocessed total melting has the limitation of being cut off the at the rather meager value of 0.35 cm/day, I can't but suppose that the computed melt is much higher at many ice edge locations.
This tool can be validated, no better moment than September. During those few days when the pack goes white in the concentration maps and compactness has a fast increase, this tool will have to show mostly zero or negative melt (refreeze) in general inside the pack.

Arctic sea ice / Re: The 2017 freezing season
« on: August 23, 2017, 10:44:14 PM »
Ned very interesting. Off the cuff, most areas minimum is determined by export into them. Best shown by the Greenland Sea. The CAB is really the best indicator for real freezing onset.
In addition I suspect your criteria are picking up weirdness somehow. Hudson refreezing on day 220? Bering refreezing before Chukchi? Possibly small transitory blips cause this. Maybe add a threshold criterion of an absolute or percentage gain to mark a day as past the minimum. And/or use the last time at the minimum rather than the first.
Great, this is exactly the response I wanted.

* Yes, it's quite possible that export (er, "import" in this case) is actually what produces the first rise after minimum in many basins in many years.

* Yes, some of the "weirdness" you identified was due to my poor choice of using the first increase after the first instance of the minimum.  I've now re-done the graph using the first day of increase after the last instance of the minimum:

The results are somewhat different, including addressing both the points of weirdness that you identified (though in 2000 the Bering still shows its first increase only three days after the Chukchi). 

Here are the updated medians:

GrnLS   239   26-Aug
Baffn   250   7-Sep
CAB   256   13-Sep
CAA   258   15-Sep
KaraS   265   22-Sep
Beauf   266   23-Sep
Laptv   268   25-Sep
ESS   269   26-Sep
Baren   270   27-Sep
Chukc   273   30-Sep
Hudsn   274   1-Oct
Okhot   311   7-Nov
Berng   312   8-Nov

I'm going to continue to think about this and see if I can come up with further improvements.
Greatness! Thanks Oren for suggesting the improvement.
We don't have a NASA cluster yet a nice list of what to expect region by region in the coming weeks based on past years, that's more than expected. Thanks Ned.
Of course there is the unpredictability component.

Arctic sea ice / Re: The 2017 freezing season
« on: August 23, 2017, 06:27:31 PM »
@Ned nice job, for further discredit of my opening post :)
For the last metric, I was expecting area to really start reaching bottom, but not really. As unusual as this season usually has been. The area curve should be getting flat now and extent keep dropping, not the opposite.

Arctic sea ice / Re: The 2017 freezing season
« on: August 23, 2017, 10:01:45 AM »
Every party needs a pooper, that's why we invited you. Party pooper.
I am not going to respond to your insult.
My speculation has easily been put in question by cold numbers (see Ned's above) and experience (see Neven's above), but it is not affected by insults.
We can make of this, 1 Cross-firing of ad-hominems WUWT Style, 2 A dead thread until the freezing season is well-acknowledged 3 Somewhere to place facts of starting symptoms of the pack refreezing even before the minimum, be it on August or October, ... or not refreezing if you wish
I prefer 2 or 3

Arctic sea ice / Re: The 2017 freezing season
« on: August 23, 2017, 12:26:58 AM »
Every JAXA daily minimum so far has been during the two week interval of Sept 7-21.

On average, a slowdown like this occurs 11 days before the minimum ... but it ranges from 28 days before minimum (in 2005) to 2 days after minimum (in 2008).

The fascinating thing, though, is that an early slowdown like this is anticorrelated with an early minimum.  Years with an early slowdown tend to have late minimums.
The data are noisy and the standard error is large, but the p-value is highly significant (0.012) at a=0.05.

Based on that model, one would expect the 2017 minimum to be somewhere between days 257-271 (i.e., September 13-27) with a best estimate of day 264 (Sept 20).

Make of it what you will.
 Yes, it may happen, at least you have the numbers, I just have the hunch this year will be slow and early, adding noise to the stats. Been a weird melting season.

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