And we begin

[DTWXRISK]

MONSTER  500MB   SURFACE  PATTERN  LAST 10 DAYS OF OCT  IN  SIBERIA

 

WOW... i  mean  just  plain FOOKING  WOW

 

 DAY 6   

 

 

 DAY 9

 

 

 

[millwx]

Millwx/Mitchnick,

 I'm roughly estimating there was a whopping 1-1.5 msk gain today, alone! I'm guessing the losses yesterday were only a couple of hundred thousand. I think Rutgers will update pretty soon (maybe within an hour based on other days) but I may be mistaken. I thought I recall them sometimes doing these udates before bed. Regardless, the models, were, indeed, spot on. This has been a tremendous Oct. so far and with more to come during the next couple of days! This snow advance is pretty relentless. The only thing that may slow it down markedly is that it is liable to start to run out of room since it is so early in the season. Regardless, the model consensus predicts healthy snowfall in many areas til the end of the month, including some new areas. We are getting closer and closer to the point where a strong -AO this winter would become likely based on analogs!

 

GaWx, I caught your original post before you deleted/edited it, lol!  So, I knew you were assuming, as I am, that what "mitchnick" posted was the new data.  Assuming this is the case... One minor (positive) area of disagreement with you... while the models were, indeed, spot on with the major increase in/near Europe, there also appears to be a smaller, but NOT insignificant increase along the southern edge near Mongolia (which the models did NOT predict well).  That is big for two reasons... #1:  I know one of the key years to beat (1978) was stretching into that area.  And #2:  I don't know if all of that near-Europe snowfall is within the "Eurasian" domain (I don't know the specific definition of that domain... some of that snow MIGHT be too far west); so, achieving gains elsewhere is important in ensuring significant day-on-day gains.

 

...now let's see if the Rutgers data follows suit, as we suspect.

 

EDIT:  As I speak, Rutgers updated.  It doesn't match the NOAA site identically (not quite the Mongolian expansion) but, for the most part, it does.  Good increases, esp. in the west, near Europe.  Hey, "Mitchnick", good catch... I didn't realize the NOAA site updated before Rutgers.

[GaWx]

Millwx,

 Comparing the anomaly with the normal for his date via eyeballing, it looks to me that we're very close to being a whopping 75% above the normal for 10/19 in Eurasia! For those not following this too closely, no sensationalizing is being done here...this is really happening, folks!

[InstantWeatherMaps]

GFS is spitting out huge snow cover amounts by the end of the month.

Source

 

 

The 00Z is actually one of the tamer recent GFS runs as well when it comes to snow cover... the 18Z, for instance, goes absolutely ballistic with the end result.

Source

 

By comparison, here is the current snow cover:

Source

 

This, along with the unusually early appearance of Wave 1 activity in the stratosphere, looks very promising for a -AO this winter.

[griteater]

And #2:  I don't know if all of that near-Europe snowfall is within the "Eurasian" domain (I don't know the specific definition of that domain... some of that snow MIGHT be too far west); so, achieving gains elsewhere is important in ensuring significant day-on-day gains.

 

The Eurasia definition in Cohen's SAI paper is essentially all of Europe and Asia.  Specifically, it states it as 25-85 deg N and 0 to 180 deg E

[GaWx]

The Eurasia definition in Cohen's SAI paper is essentially all of Europe and Asia.  Specifically, it states it as 25-85 deg N and 0 to 180 deg E

 

 Based on that def., I roughly estimate Eurasian snowcover is ~16.5 as of 10/19. I've been saying that getting to near 19.5 as of 10/31 would be a very important milestone. Why? That much would make 2014's Eurasian Oct. snow increase ~14 msk, meaning the 4th highest of 46 and in territory suggesting the likehood of a strong (<-1) -AO for DJF averaged as per analogs, especially if a Nino is finally starting. Even a very rare <-2 AO wouldn't at all be out of the question! I say this because there have been only three sub -2 AO DJF's since 1950-1: 1968-9, 1976-7, and 2009-10. All three of these were Nino's with an Oct. Eurasian snowcover increase of 13.75+. Only six of 46 had 13.75+.

 So, the big milestone imo would be hit if a net 3 msk were to be added by 10/31. Per model consensus for snowfall and cold, this would seemingly be quite doable though I'm not yet ready to call this likely.

[wildweatherman179]

That forecast snow growth is absolutely nuts. So is the current ice growth. Very awesome to see.

[wildweatherman179]

Based on that def., I roughly estimate Eurasian snowcover is ~16.5 as of 10/19. I've been saying that getting to near 19.5 as of 10/31 would be a very important milestone. Why? That much would make 2014's Eurasian Oct. snow increase ~14 msk, meaning the 4th highest of 46 and in territory suggesting the likehood of a strong (<-1) -AO for DJF averaged as per analogs, especially if a Nino is finally starting. Even a very rare <-2 AO wouldn't at all be out of the question! I say this because there have been only three sub -2 AO DJF's since 1950-1: 1968-9, 1976-7, and 2009-10. All three of these were Nino's with an Oct. Eurasian snowcover increase of 13.75+. Only six of 46 had 13.75+.

So, the big milestone imo would be hit if a net 3 msk were to be added by 10/31. Per model consensus for snowfall and cold, this would seemingly be quite doable though I'm not yet ready to call this likely.

I'd take a winter 1976-77 for sure!

[millwx]

The Eurasia definition in Cohen's SAI paper is essentially all of Europe and Asia. Specifically, it states it as 25-85 deg N and 0 to 180 deg E

He starts at zero east?!?!?! Seems excessive to me, but I won't question it... he's the one that's done the research. As I've noted numerous times, I'm more locked into raw coverage, not increase. For that I use Rutgers' numbers. I wonder if they use the same definition. Their documentation online is, shall we say, limited. But when I get in the office I'll see if I can find it. But if they use the same, then we've gotten another huge jump today... and we certainly have with the SAI. Thanks for posting that info, Griteater... very helpful.

[DaculaWeather]

Rutger's on the 17th and the 19th/ For whatever reason, the timing of the frames isn't being displayed properly...

 

[WidreMann]

GFS is spitting out huge snow cover amounts by the end of the month.

Source

 

 

The 00Z is actually one of the tamer recent GFS runs as well when it comes to snow cover... the 18Z, for instance, goes absolutely ballistic with the end result.

Source

 

By comparison, here is the current snow cover:

Source

 

This, along with the unusually early appearance of Wave 1 activity in the stratosphere, looks very promising for a -AO this winter.

The wave 1 activity is comparable to, or weaker than, last year's. I don't know how much I'd bet on that.

[cfbaggett]

Sorry for the delay in posting... I've been traveling. Things are looking very good for snow extent. The jury is still out for snow advance, but IMO I think we are heading in the right direction!

 

[griteater]

Sorry for the delay in posting... I've been traveling. Things are looking very good for snow extent. The jury is still out for snow advance, but IMO I think we are heading in the right direction!

 

Thanks baggett for the update.  Looks good.  What is the definition of the 2 slope lines?  Is that the linear regression of the snow totals (i.e. best fit line of the data points for the 2 years, 2009 and 2007)?

[cfbaggett]

Thanks baggett for the update.  Looks good.  What is the definition of the 2 slope lines?  Is that the linear regression of the snow totals (i.e. best fit line of the data points for the 2 years, 2009 and 2007)?

That's correct. Where 2009 (2007) represents the greatest (least) slope in Cohen's SAI data series.

[GaWx]

 Looking at cfbaggett's graph of sub 60N Eurasian daily changes for Oct., yesterday's gain was ~1.3 msk (just after 10/18's loss of ~0.2), making it the 2nd highest gain of the month to 10/11's ~1.4 msk. In 3rd is 10/17's ~+1.1 msk. Out of 18 days from 10/1, there were five days of losses vs. 13 days of gains. Four of those five losses were in the ~0.1 to 0.2 range. However, the biggest loss, 10/13, was a whopping 0.7.

[GaWx]

 More analysis of cfbaggett's graphs:

 

 Looking at the graph of the five years, the 10/11/14, 10/17/14, and 10/19/14 increases are among the largest one day sub 60N increases of the five years. Looking at days with 1.0+ increases, 2014 has had three so far and we're only through 10/19! In stark contrast, 2013 looks like it had either one or zero. 2012 appears to have had two. 2009 looks like it had three though four is possible. 2007 had only one.

 

So, # of 1.0+ sub 60N Eurasian Oct. daily gains:

 

2014: 3 (that's only through 10/19)

2009: 3 (to possibly 4)

2012: 2

2007: 1

2013: 0 or 1

 

Estimate of total Oct. sub 60N Eurasian gains (correlates pretty well to # of sub 60N 1.0+ Oct. daily gains):

 

2014: 5.3 (that's only through 10/19)

2009: 7.4

2012: 6.5

2007: 3.9

2013: 3.8

 

Estimate of total Oct. Eurasian gains (correlates well to sub 60N gains):

 

2014: 11.0 (that's only through 10/19)

2009: 16.0

2012: 15.5

2007: 10.0

2009:   9.0

 

 So, note that the ratio of total Eurasian gains to sub 60N Eurasian gains was within the 2 to 2.6 range. I've been saying that reaching ~14.0 for the Oct. total Eurasian increase would be a major milestone as it would put 2014 in the top 4 of 46 years and in really good shape for chances for a strong -AO during DJF based on the other 13.75+ gain years and with 2014 likely going into a Nino. So, based on these 2-2.6 ratios it would seem that a good target for sub 60N Oct. gains would be ~7.0, which is only 1.7 higher than the month to date gain of 5.3. So, if we could get cfbaggett's graph to show 2014 sub 60N extent reaching 8.5+ as of 10/31 from the current ~6.7, that would be very good news for those wanting a strong DJF -AO. Even getting to just 8.0 extent may be enough.

[GaWx]

Fwiw: If the 12Z Euro is to be believed, there could as much as ~3 msk of current bare ground in Eurasia between 40N and 55N getting 1''+ of snow just during the next 7 days, alone, due mainly to three storms (two in E Europe/W Asia area and one in E Asia)! We'll see. Even if that occurs, we'd need to see how much would melt back by 10/31. Regardless, that would be enough snowfall to give us a really good shot at making it at least to 8 msk in sub 60N Eurasia as of 10/31, which would be a huge milestone, even after allowing for a decent amount of melting being that we're already at 6.7 as of yesterday. Based on the model's projection of very cold dominating much of E. Europe and western Asia north of 40N and much of E Asia north of 50N through 10/30, there may not be a whole lot of melting soon afterward.

[hosj III]

Fwiw: If the 12Z Euro is to be believed, there could as much as ~3 msk of current bare ground in Eurasia between 40N and 55N getting 1''+ of snow just during the next 7 days, alone, due mainly to three storms (two in E Europe/W Asia area and one in E Asia)! We'll see. Even if that occurs, we'd need to see how much would melt back by 10/31. Regardless, that would be enough snowfall to give us a really good shot at making it at least to 8 msk in sub 60N Eurasia as of 10/31, which would be a huge landmark, even after allowing for a decent amount of melting being that we're already at 6.7 as of yesterday. Based on the model's projection of very cold dominating much of E. Europe and western Asia north of 40N and much of E Asia north of 50N through 10/30, there may not be a whole lot of melting soon afterward.

Wouldn't a spike like that still enhance the SAI?

[griteater]

On 12z Euro Ensemble, the negative height anomalies keep pushing south.  Pattern pretty much looks ideal in western and central Eurasia for continued snow advance...ridging builds into far eastern Eurasia in the last 5 days of the month, so not as good to end the month there.

[GaWx]

Wouldn't a spike like that still enhance the SAI?

 

 Yes. SAI considers the entire Oct increase below 60N. If we can tack on another several msk of Eurasian snowcover, there's little doubt that that would be better for DJF strong -AO chances. In my mind, the goal is to get close to 14 msk TOTAL Eurasian increase in October to get within elite territory. So, we need about another 3 msk for TOTAL Eurasian increase based on my estimates. Getting to 7 msk of sub 60N Eurasian increase (8-8.5 of sub 60N extent) would be consistent with this goal based on past 2-2.5 ratios of total Eurasian to sub 60N Eurasian.

 Bottom line: these last 12 days of the month are very important as the story is far from concluded even though so far things look great and about as good as could be for 10/19. Models are pretty encouraging for these last 12 days overall based on model projected snowfall within 40-55N and continued domination of cold in many areas.

[GaWx]

 The new Euro weeklies are absolutely frigid for this time of year over much of Asia (outside of China) and E Europe through week #2 (through 11/2). Many areas are a whopping 9 F or more below normal (off of the scale) for these two weeks! The size of this very cold area is massive: ~7,000 miles long and 1-2K miles wide! Also, precip. is near to a bit above normal over most of the crucial sub 60N areas of E Europe and Asia. So, it is hard to imagine a much better pattern for both generating new snow as well as preserving what's on the ground through 10/31+. This bodes quite well for a solid last 11 days of the month to go with the already excellent first 20 days.

[AlaskaETC]

 The new Euro weeklies are absolutely frigid for this time of year over much of Asia (outside of China) and E Europe through week #2 (through 11/2). Many areas are a whopping 9 F or more below normal (off of the scale) for these two weeks! The size of this very cold area is massive: ~7,000 miles long and 1-2K miles wide! Also, precip. is near to a bit above normal over most of the crucial sub 60N areas of E Europe and Asia. So, it is hard to imagine a much better pattern for both generating new snow as well as preserving what's on the ground through 10/31+. This bodes quite well for a solid last 11 days of the month to go with the already excellent first 20 days.

 

Wow...topping 2009 might be a possibility then?

[griteater]

Here's the pattern (in Eurasia) that's delivered the snow thus far in Oct...

 

And here's today's 6-10 day mean on the Euro Ensemble to close out the month...

[Mallow]

If I remember Cohen's figures correctly, a ridge over northeast Siberia migrating to north-central Siberia through October (and subsequently up to the Arctic for the winter) is one of the telltale markers of a strong snow-advance/-AO year.

[millwx]

Natice site seems to be down.  Arg!  Since Rutgers updates after Natice, hope they don't depend on it for their raw data.  Or hope Natice comes back up quickly.

[WidreMann]

If I remember Cohen's figures correctly, a ridge over northeast Siberia migrating to north-central Siberia through October (and subsequently up to the Arctic for the winter) is one of the telltale markers of a strong snow-advance/-AO year.

Hope you didn't remember it backwards or we're screwed.

[Chinook]

Omsk, Russia (Population 1 million) will have to do some digging out after near-blizzard conditions

 

Conditions at: UNOO observed 20 October 2014  21:00 UTC Temperature: -3.0°C (27°F) Dewpoint: -4.0°C (25°F) [RH = 93%] Pressure (altimeter): 29.29 inches Hg (992.0 mb) Winds: from the NW (310 degrees) at 26 MPH (23 knots; 12.0 m/s)
gusting to 43 MPH (37 knots; 19.2 m/s) Visibility: 0.25 miles (0.40 km) Ceiling: indefinite ceiling with vertical visibility of 600 feet AGL Clouds: obscured sky Present Weather: BLSN +SHSN  (blowing snow, heavy snow showers) UNOO 202100Z 31012G19MPS 0400 R25/0800V1000D +SHSN BLSN VV006 M03/M04 Q0992 25490538 TEMPO 30017MPS 0200 +SHSN BLSN VV002 RMK QBB180 OBST OBSC QFE736

[GaWx]

I just found this by accident. Any opinions on this as regards Rutgers Oct. Eurasian SCE? Also, how credible is this study?

http://m.iopscience.iop.org/1748-9326/8/2/024006

[ORH_wxman]

I just found this by accident. Any opinions on this as regards Rutgers Oct. Eurasian SCE? Also, how credible is this study?

http://m.iopscience.iop.org/1748-9326/8/2/024006

 

 

I hadn't seen that paper get any play and its 18 months old now...NOAA hasn't changed their dataset though. If it was obviously faulty, they probably would. There was a recent paper that came out trying to show that the increase in Antarctic Sea Ice was a spurious internal trend as well, but NSIDC thought it was baseless. (even issuing a statement about it)

 

I guess the only way to know for sure is to ask someone who works with the Natice/NOAA dataset. The 1982-2011 trend is massively positive in October snow cover. That would be a really egregious error by the NOAA datset if the entire thing was spurious. That would also probably be a blow to Cohen's work showing that more positive AO period from the 1980s/1990s was in part due to reduced October Siberian snow cover.

[Drz1111]

But it's an important warning to those of you who like playing with multi-decade data sets that your trend or correlation is only good as the consistency of the way in which the data is measured. Particularly so since the temp trend has generally pointed in one way since the late 70s, when many of these data sets start, so a systematic change in one direction can look correlated with warm even if it's just an artifact. One satellite switch or refinement to code at NOAA a can really screw your work up, and you may not even know about it. Happened to a guy I went to grad school with and boy did he feel stupid when he found out.