And we begin

[Weltanschauung]

SAI:

 

[hosj III]

Impressive.  As you know, I look at raw coverage for Week 42.  Looking at it that way, it's 1976 and 1978 (not 1966) that top the list.  The coverage now (we are midway through Week 42) is on par with 1978.  Sorry, because of the image handling for the weeklies on the Rutgers site, I can't post 1978 here.  But compare today:

 

 

...to the image at this link:

 

http://climate.rutgers.edu/snowcover/chart_vis.php?ui_year=1978&ui_week=42&ui_set=0

 

In the details, looks like this year still trails 1978 a little - we definitely have less around the edges right now.  But the weeklies, to the best of my knowledge, are just a daily snapshot at the END of the week. So, if we get any further expansion over the next four days, this could easily match or even surpass 1978.  Of course, at this time of year, that's a big "if"... we could, potentially, see melt around the edges over the next several days.  We'll just have to wait and see.  But clearly, this is some pretty epic snow cover we've got right now.  Of course, high snow cover is still no guarantee (hello 2006!), but it sure doesn't hurt!

http://www.instantweathermaps.com/GFS-php/showmap-nh.php?run=2014101812&var=SNOWC_sfc&hour=132

 

GFS showing pretty good gains by the 23rd. We'll probably top 1978, if just barely.

[GaWx]

http://www.instantweathermaps.com/GFS-php/showmap-nh.php?run=2014101812&var=SNOWC_sfc&hour=132

 

GFS showing pretty good gains by the 23rd. We'll probably top 1978, if just barely.

 

 Actually, a better date match for week 42 would be earlier such as this one (0Z 10/21), which actually shows more snow than the one as of 10/23 due to melt of some of the new snow in western regions during the 10/21-3 period (this looks similar to 1978 to me with my estimate of a whopping 17 msk):

 

http://www.instantweathermaps.com/GFS-php/showmap-nh.php?run=2014101812&var=SNOWC_sfc&hour=060

 

Edit: So, per several recent GFS/Euro runs, I'm projecting that the week 42 # will be near 17 msk, which would be near 1978 and would trail only 1976, which was near 18 msk.

[Yanksfan]

 Actually, a better date match for week 42 would be earlier such as this one (0Z 10/21), which actually shows more snow than the one as of 10/23 due to melt of some of the new snow in western regions during the 10/21-3 period (this looks similar to 1978 to me with my estimate of a whopping 17 msk):

 

http://www.instantweathermaps.com/GFS-php/showmap-nh.php?run=2014101812&var=SNOWC_sfc&hour=060

 

Edit: So, per several recent GFS/Euro runs, I'm projecting that the week 42 # will be near 17 msk, which would be near 1978 and would trail only 1976, which was near 18 msk. Being a big winter fan myself, that's good to hear. However, unless we have the proper teleconnections to bring all that cold air down to the states, all that snow cover way up north would be a mute point.

[Yanksfan]

 Actually, a better date match for week 42 would be earlier such as this one (0Z 10/21), which actually shows more snow than the one as of 10/23 due to melt of some of the new snow in western regions during the 10/21-3 period (this looks similar to 1978 to me with my estimate of a whopping 17 msk):

 

http://www.instantweathermaps.com/GFS-php/showmap-nh.php?run=2014101812&var=SNOWC_sfc&hour=060

 

Edit: So, per several recent GFS/Euro runs, I'm projecting that the week 42 # will be near 17 msk, which would be near 1978 and would trail only 1976, which was near 18 msk.

Being a big winter time fan myself, that's good to hear. However, unless we have the proper teleconnections to bring the cold air down, all that snow cover up north would all be a mute point.

[DTWXRISK]

then you are  totally missing  the point... the  snow cover  in siberia if it is  of the right size and timing and build  up ...makes the  pattern in North America  much more favorable  for get the cold air  ": down" into the  conus

 

Being a big winter time fan myself, that's good to hear. However, unless we have the proper teleconnections to bring the cold air down, all that snow cover up north would all be a mute point.

[GaWx]

 I just realized that assuming we really do get close to 17 msk as of 10/20/14, that would almost surely be much higher than week 42 for 1978. Why? Because week 42 in 1978 ended on 10/23, not 10/20, per the site:

 

http://climate.rutgers.edu/snowcover/chart_vis.php?ui_year=1978&ui_week=42&ui_set=0

 

 Look at the dates in the left margin: week 42 10/17-23/1978

 

 Keep in mind that week 42 saw massive increases in 1978 as per looking at this week 41 of '78 map:

 

http://climate.rutgers.edu/snowcover/chart_vis.php?ui_year=1978&ui_week=41&ui_set=0

 

 As this shows, SCE was only 5.64 msk as of week 41 of 1978! So, that means there was an increase of >11 msk during week 42 of '78! If I were to interpolate to make a guess as to the 10/20/78 SCE, I'd come up with only ~12 msk. So, week 42 in 2014, which would be as of 10/20/14, will be way ahead of week 42 in 1978 in all likelihood.

 

 That would leave only 1976 to be ahead of 2014. 1976's week 42 ended on 10/18/76. meaning the opposite adjustment is needed:

 

http://climate.rutgers.edu/snowcover/chart_vis.php?ui_year=1976&ui_week=42&ui_set=0

 

 So, I need to interpolate between week 42 and week 43 for 1976. Week 42 was at 18.39 msk while week 43 was at 22.55. Interpolation yields ~20 msk as of 10/20/76, which means 2014 would be ~ 3 msk behind 1976 for 2nd place as of 10/20.

 

 To summarize, here are the three years in question as of 10/20 per interpolations for 76 and 78 and per model consensus estimates for 2014:

 

 1976: 20

 2014: 17 projection est.

 1978: 12

 

 Actually, '78 falls behind these others using interp.: 66, 70, 71, 02, 04, 06, 13.  So, '78 would end up is in 10th place. However, '14 would safely remain in 2nd place. '66 would be in 3rd at ~15. Then, 70, 71, 02, 04, 06, and 13 would all be within 12-15.

 

So, as of 10/20:

 

1976: 20

2014: 17 projection est.

1966: 15

70, 71, 02, 04, 06, and 13: 12-15

1978: 12

 

  *** This paragraph now outdated because underlying calc.'s have been redone more accurately. See below this. If we do get to ~17 as of 10/20/14, that would mean already over 11 for the SAI, which would be already near the average SAI for the entire month...and that's with ~2 higher than average start to the month (2 handicap of sorts)! The largest SAI for the entire Oct. was 1976's ~21. 2nd was 2009's ~16. 3rd was 2012's ~15.5. 4th was 1970's ~14.5. 5th was 2003's ~14.25. 6th was 1968's ~14. So, with 2014 being projected to be over 11 as of 10/20, there will be a reasonable chance for it to make it ahead of 1968, 2003, and 1970 for the whole month. Beating the ~15.5-16 of 2012 and 2009 will be a challenge though stil possible. 1976 is virtually unbeatable.***

-----------------------------------

 

 

**EDIT** To be fair, I need to look at these top years again and make sure the differing dates for each week from year to year won't make me feel an interp. based adj. is best.

 I just redid these with interp.'s and the rankings changed little though 1976 came way down while still staying #1. Here are the estimates for Oct.:

 

1976: 16.75 (had been way up at 21)

2009: 16

2012: 15.5

2003: 14

1970: 13.75

1968: 13.75

 

 To compare, 2014 is projected to be over 11 as of 10/20 and with 11 days still to go. Passing 2003, 1970, and 1968 would be quite doable assuming a continued snowy pattern, which would put 2014 in 4th place out of 46 years. Passing any of the top three will be tough though not nearly at all far-fetched assuming the snowy pattern stays.

[Yanksfan]

then you are  totally missing  the point... the  snow cover  in siberia if it is  of the right size and timing and build  up ...makes the  pattern in North America  much more favorable  for get the cold air  ": down" into the  conus

 

If that's the case, along with our developing EL Nino, then we could potentially be looking at one heck of a winter. It'll be interesting to say the least how it all works out.

[hosj III]

then you are  totally missing  the point... the  snow cover  in siberia if it is  of the right size and timing and build  up ...makes the  pattern in North America  much more favorable  for get the cold air  ": down" into the  conus

 

A crappy pacific can easily negate a favorable AO. Look at 2012-2013.

[weathafella]

Being a big winter time fan myself, that's good to hear. However, unless we have the proper teleconnections to bring the cold air down, all that snow cover up north would all be a mute point.

Being a big winter time fan myself, that's good to hear. However, unless we have the proper teleconnections to bring the cold air down, all that snow cover up north would all be a mute point.

Meaning we won't hear about it?

[weathafella]

A crappy pacific can easily negate a favorable AO. Look at 2012-2013.

Speaking for mby....I'd take that winter again.

[RONALD B]

A crappy pacific can easily negate a favorable AO. Look at 2012-2013.

U mean 2012-2013 the 2nd year lanina ?

[Ginx snewx]

then you are  totally missing  the point... the  snow cover  in siberia if it is  of the right size and timing and build  up ...makes the  pattern in North America  much more favorable  for get the cold air  ": down" into the  conus

 

WAPO graphic

[millwx]

A crappy pacific can easily negate a favorable AO. Look at 2012-2013.

You're both right. DT is correct that the snow cover causes the forcing. So, saying that it can still get screwed if the pattern is bad is a little blind to the fact that the snow cover is helping to MAKE the pattern. On the other hand, the entire system is complex and the snow cover isn't 100% successful (ahem, 2006)... because it IS correct to say that other factors, if they're bad enough, can run over any snow effects like a freight train.

Bottom line... this snow cover isn't the be all and end all, but it IS important. It's also particularly helpful because it has a longer lead time than most other drivers. So, for the other drivers we're still depending on forecasts of the drivers, which may be inaccurate. But for the snow cover, this is real-time, factual, settled data. It's one of the only forcing mechanisms that can be viewed as a 100% guaranteed lock (by next week). So, yes, it's imperfect and the signal COULD fail. But it's one of the best pieces of info on hand right now.

[millwx]

I just realized that assuming we really do get close to 17 msk as of 10/20/14, that would almost surely be much higher than week 42 for 1978. Why? Because week 42 in 1978 ended on 10/23, not 10/20, per the site:

http://climate.rutgers.edu/snowcover/chart_vis.php?ui_year=1978&ui_week=42&ui_set=0

Look at the dates in the left margin: week 42 10/17-23/1978

Keep in mind that week 42 saw massive increases in 1978 as per looking at this week 41 of '78 map:

http://climate.rutgers.edu/snowcover/chart_vis.php?ui_year=1978&ui_week=41&ui_set=0

As this shows, SCE was only 5.64 msk as of week 41 of 1978! So, that means there was an increase of >11 msk during week 42 of '78! If I were to interpolate to make a guess as to the 10/20/78 SCE, I'd come up with only ~12 msk. So, week 42 in 2014, which would be as of 10/20/14, will be way ahead of week 42 in 1978 in all likelihood.

That would leave only 1976 to be ahead of 2014. 1976's week 42 ended on 10/18/76. meaning the opposite adjustment is needed:

http://climate.rutgers.edu/snowcover/chart_vis.php?ui_year=1976&ui_week=42&ui_set=0

So, I need to interpolate between week 42 and week 43 for 1976. Week 42 was at 18.39 msk while week 43 was at 22.55. Interpolation yields ~20 msk as of 10/20/76, which means 2014 would be ~ 3 msk behind 1976 for 2nd place as of 10/20.

To summarize, here are the three years in question as of 10/20 per interpolations for 76 and 78 and per model consensus estimates for 2014:

1976: 20

2014: 17 projection est.

1978: 12

**EDIT**

Actually, '78 falls behind these others using interp.: 66, 70, 71, 02, 04, 06, 13. So, '78 would end up is in 10th place. However, '14 would safely remain in 2nd place. '66 would be in 3rd at ~15. Then, 70, 71, 02, 04, 06, and 13 would all be within 12-15.

So, as of 10/20:

1976: 20

2014: 17 projection est.

1966: 15

70, 71, 02, 04, 06, and 13: 12-15

1978: 12

Edit #2: If we do get to ~17 as of 10/20/14, that would mean already over 11 for the SAI, which would be already near the average SAI for the entire month...and that's with ~2 higher than average start to the month (2 handicap of sorts)! The largest SAI for the entire Oct. was 1976's ~21. 2nd was 2009's ~16. 3rd was 2012's ~15.5. 4th was 1970's ~14.5. 5th was 2003's ~14.25. 6th was 1968's ~14. So, with 2014 being projected to be over 11 as of 10/20, there will be a reasonable chance for it to make it ahead of 1968, 2003, and 1970 for the whole month. Beating the ~15.5-16 of 2012 and 2009 will be a challenge though stil possible. 1976 is virtually unbeatable.

To be fair, I need to look at these top years again and make sure the differing dates for each week from year to year

won't make me feel an interp. based adj. is best.

GaWx, your posts on this are great. Keep it coming! It will be VERY interesting to see where we end up by mid next week. It will also be interesting to see if the climo models get affected by this and start cooling off. Most of them did cool in their October runs, but the CFS is still torching. I *think* (I'd have to go back and check... operating on memory here) it began abandoning it's warm winter forecast last year around mid-October, just after the impressive increase in Siberian snow cover. So, it'll be interesting to see what effect this has on the models, if any.

[GaWx]

GaWx, your posts on this are great. Keep it coming! It will be VERY interesting to see where we end up by mid next week. It will also be interesting to see if the climo models get affected by this and start cooling off. Most of them did cool in their October runs, but the CFS is still torching. I *think* (I'd have to go back and check... operating on memory here) it began abandoning it's warm winter forecast last year around mid-October, just after the impressive increase in Siberian snow cover. So, it'll be interesting to see what effect this has on the models, if any.

 

Thanks. I just looked at the top years again for total Oct. SAI and redid these with interp.'s due to variations from year to year regarding the exact days for each week. The rankings changed little though 1976 came way down while still staying #1. Here are the estimates for Oct. SAI:

 

1976: 16.75 (had been way up at 21)

2009: 16

2012: 15.5

2003: 14

1970: 13.75

1968: 13.75

 

 To compare, 2014 is model projected to be over 11 as of 10/20 and with 11 days still to go. Passing 2003, 1970, and 1968 would be quite doable assuming a continued snowy pattern, which would put 2014 in 4th place out of 46 years. Passing any of the top three will be tough though not nearly at all far-fetched assuming the snowy pattern stays. Getting to ~14 for this year's final SAI would seem to be a pretty nice landmark to pass as that would put 2014 in pretty select company with very good chances for a solidly -AO this winter. 5 of these top 6 all had DJF AO's of < -1 and 3 of them had it <-2!

**Edit** These 3 within this group of 6 that had sub -2 DJF AO's were the only Nino's in this group of 6 as well as the only sub -2's since at least 1950-1...now that's even more encouraging should 2014 reach 14 for SAI.

[millwx]

Thanks. I just looked at the top years again for total Oct. SAI and redid these with interp.'s due to variations from year to year regarding the exact days for each week. The rankings changed little though 1976 came way down while still staying #1. Here are the estimates for Oct. SAI:

1976: 16.75 (had been way up at 21)

2009: 16

2012: 15.5

2003: 14

1970: 13.75

1968: 13.75

To compare, 2014 is model projected to be over 11 as of 10/20 and with 11 days still to go. Passing 2003, 1970, and 1968 would be quite doable assuming a continued snowy pattern, which would put 2014 in 4th place out of 46 years. Passing any of the top three will be tough though not nearly at all far-fetched assuming the snowy pattern stays. Getting to ~14 for this year's final SAI would seem to be a pretty nice landmark to pass as that would put 2014 in pretty select company with very good chances for a solidly -AO this winter. 5 of these top 6 all had DJF AO's of < -1 and 3 of them had it <-2!

**Edit** These 3 within this group of 6 that had sub -2 DJF AO's were the only Nino's in this group of 6...now that's even more encouraging should 2014 reach 14 for SAI.

UKMO did a study in support of their GloSea5 model and found an autumn El Niño is correlated to a -NAO winter. Given the relationship between the AO and NAO it doesn't surprise me that a Niño helps amplify the -AO. Now, whether or not we have an autumn El Niño this year is questionable (only half way thru Oct so far)... but we should, albeit a weak one. Given that it'll be weak, I suspect it's influence will be small. But it should try to at least slightly push the NAO and AO negative.

...anyway, point is, it makes complete sense that the Niño-Snow pairing provides the best -AO signal.

[GaWx]

IF the 12Z Euro ensemble mean were to be close to reality, Eurasian SCE could very well reach the 19.5-20 msk range at the end of the month (2nd highest of last 46 years to 1976). If that were to occur, the 2014 Oct. SAI would end up around the 14-14.5 area, which would make it the 4th highest of 46 years. If that were to occur and if we actually get El Niño, it would appear that a strong -AO in DJF would actually become, dare I say, likely based on all of the indicators.

**Edit: In concert with the advancing snowcover, this Euro ens run has significant below normal temp. anomalies dominating Asia north of 50N and E Europe for the rest of this month (i.e., over the bulk of the snowcovered areas)

[chionomaniac]

The depth is directly based off the snow depth parameter in the GFS model, without any post-processing. Oftentimes the observed time-0 snow depth can be a bit off (such as showing a placeholder amount of an inch or two when actually a lot more fell but no confirmed observations have happened yet), but not much can be done about that without compromising my maps' equality with the raw model output.

 

You probably meant to post the image below. For bandwidth and archival reasons we don't allow hotlinking of our images. I highly encourage posting of images from my site, though; just use a site like Imgur to rehost them instead of directly linking. There is a wonderful Firefox addin that turns the uploading into a one-click task as well.

 

Hi, can I ask a question please?

 

In the sfc snow cover graphs and change of sfc snow cover graphs there is a percentage figure in the bottom right hand corner. Is this figure a percentage of the whole Northern hemisphere ( rather than say a percentage figure of the gain, for instance)?

 

Thanks.

[InstantWeatherMaps]

Hi, can I ask a question please?

In the sfc snow cover graphs and change of sfc snow cover graphs there is a percentage figure in the bottom right hand corner. Is this figure a percentage of the whole Northern hemisphere ( rather than say a percentage figure of the gain, for instance)?

Thanks.

It is in fact the percent of the entire Northern Hemisphere -- specifically, the areal average in the Northern Hemisphere of the binary variable defined by {1 if snow depth > 1 inch, 0 otherwise}. The change is the absolute percentage value of change, not the relative percentage compared to the original. (Example: a change from 10% to 11% is +1%, not +10%)

[chionomaniac]

It is in fact the percent of the entire Northern Hemisphere -- specifically, the areal average in the Northern Hemisphere of the binary variable defined by {1 if snow depth > 1 inch, 0 otherwise}. The change is the absolute percentage value of change, not the relative percentage compared to the original. (Example: a change from 10% to 11% is +1%, not +10%)

Thanks, that is what I thought but just wanted to check.

[millwx]

Looks like we lost a bit of snow cover in the last 24 hours  (http://climate.rutgers.edu/snowcover/chart_daily.php?ui_year=2014&ui_day=291&ui_set=0 ...toggle between this and previous day).    But not alarming.  Should be natural to lose a bit around the edges between events (and though I haven't looked closely at the day-to-day forecast, I'm pretty sure we're "between events", given the huge gains yesterday).  Plus, the coverage is still great.  Just a teensy, tiny bit disappointing to see us take a small step back.  Hopefully, the next event sweeps through soon and hammers them.

 

We'll see... only two days (three days of reports, since they come out the day after) left in Week 42.  Not that Week 42 is magic... Week 41 and 43 correlate well (to U.S. winter temps) as well.  Week 42 is just when the relationship/correlation peaks (oddly, the peak correlation to the winter AO is Week 43, even though the peak correlation to temps is Week 42... to me, the end result - sensible weather - is most important; so, I key in on Week 42... but it's fair to continue paying close attention through Week 43 and to the end of October - which is only a little beyond Week 43; beyond that, November is virtually irrelevant).  Anyway, over the next two days, the GFS does project an increase in snow cover:

 

 

...but it's a little bit of a mixed bag and focused over the far western portion of the area of interest.  So, it'll be interesting to see what the actual numbers end up being.  I hope someone with access to the daily numerical data will post it on here (on Tuesday... the data issued that day, for Monday, will mark the end of Week 42).  Unfortunately, Rutgers doesn't give the numbers on the dailies; and they don't update the weeklies on a regular basis (they were supposed to change this a few years ago, as I inquired about this, but they never made the change)... they wait for the end of the first week that completes in the new month, then they update the monthly chart for the previous month AND all of the weeklies for that previous month.  So, we won't get the official Week 42 number from Rutgers until November 4th, or there about.  So, I'm hoping someone with the raw SCE data who processes it themselves (so they have the numerics) will post it here.

[GaWx]

Millwx ,

Thanks for all of your very interesting info! I also noticed the fairly small snowcover loss yesterday. However, like you, I definitely feel that some loss days between events are perfectly normal. I think this is especially the case just after huge gains since the gains are likely largely pretty thin. Interestingly, even the Oct. champ 1976 struggled in late Oct. and then in the 1st half of Nov. as it got way ahead of climo before that. Regardless, my look at the 0Z models and especially the Euro ensemble mean continue to tell me that Eurasia will very likely have a sig. net gain between now and 10/31. These models continue to also show a sig. cold anomaly over much of the snowcover regions. I agree that good gains over western sections over the next 2-3 days look likely per models.

Regarding week 42 vs. the entire month's Eurasian SCE increase, I think that strictly based on the research I did yesterday that the latter has been a better indicator for DJF -AO when considering the top 6 for sure and probably a larger number than top 6, even when ignoring the calendar week differences from year to year, which demote 1978 quite a bit. Now, I realize you're talking about something totally different from DJF -AO, i.e., the average US winter temperature. So, I'm not refuting your research about week #42, itself, since I didn't look at US winter temperatures. OTOH, I can also say that Atlanta DJF temperatures and quite possibly those for much of the SE US fwiw have negatively correlated better with the top years for the entire October Eurasian SCE increase than the top years for week 42 Eurasian SCE (with or without calendar difference related adjustments). For these reasons and with the very impressive gains for 2014 so far this month even after a significant headstart that could easily have hurt 2014, I'm even more interested in the Eurasian total October SCE increase than I was before yesterday's research. I felt the need to say this because I prefer that this thread also continue to give plenty attention to SCE increase.

[millwx]

Millwx ,

Thanks for all of your very interesting info! I also noticed the fairly small snowcover loss yesterday. However, like you, I definitely feel that some loss days between events are perfectly normal. I think this is especially the case just after huge gains since the gains are likely largely pretty thin. Interestingly, even the Oct. champ 1976 struggled in late Oct. and then in the 1st half of Nov. as it got way ahead of climo before that. Regardless, my look at the 0Z models and especially the Euro ensemble mean continue to tell me that Eurasia will very likely have a sig. net gain between now and 10/31. These models continue to also show a sig. cold anomaly over much of the snowcover regions. I agree that good gains over western sections over the next 2-3 days look likely per models.

Regarding week 42 vs. the entire month's Eurasian SCE increase, I think that strictly based on the research I did yesterday that the latter has been a better indicator for DJF -AO when considering the top 6 for sure and probably a larger number than top 6, even when ignoring the calendar week differences from year to year, which demote 1978 quite a bit. Now, I realize you're talking about something totally different from DJF -AO, i.e., the average US winter temperature. So, I'm not refuting your research about week #42, itself, since I didn't look at US winter temperatures. OTOH, I can also say that Atlanta DJF temperatures and quite possibly those for much of the SE US fwiw have negatively correlated better with the top years for the entire October Eurasian SCE increase than the top years for week 42 Eurasian SCE (with or without calendar difference related adjustments). For these reasons and with the very impressive gains for 2014 so far this month even after a significant headstart that could easily have hurt 2014, I'm even more interested in the Eurasian total October SCE increase than I was before yesterday's research. I felt the need to say this because I prefer that this thread also continue to give plenty attention to SCE increase.

Nor would I refute anything you're saying. As mentioned, for AO, week 43 is best. And, as I've also noted, I *believe* the weeks are defined by their end date data. So, Week 43 this year ends 10/27. And as you've noted in your interpolation data, our weeks this year seem to be on the early side. So... Week 43, for most years, ends pretty close to the end of October. In short, yup... for your AO response, the entire month of October is relevant. Beyond that (Nov) the correlation drops precipitously.

As for the Atlanta temps... eh, can't be surprised one way or the other. It's just one datapoint. The data I use is population weighted (which will, by definition, be East weighted) US HDDs. I wouldn't be surprised at all to learn there's some regional variations in there. Furthermore, while Week 42 is the best correlation nationally, Week 41 and 43 (in that order) don't trail by much. That could simply be sampling noise. So... I'll continue to train my focus on Week 42, but Week 43 / the rest of October is ABSOLUTELY very relevant.

[griteater]

The pattern on the Euro Ensemble continues to look good for Eurasian snow advance.  Above normal anomalies at the surface and upper levels across northern Eurasia (500mb 6-10 day mean shown below), with storm systems delivering the snow to the south.

 

[CoastalWx]

I wouldn't worry about common daily fluctuations. Should be another slug of snow shoved further S and SW next week before it levels off perhaps right near the 31.

[mitchnick]

Looks like we lost a bit of snow cover in the last 24 hours  (http://climate.rutgers.edu/snowcover/chart_daily.php?ui_year=2014&ui_day=291&ui_set=0 ...toggle between this and previous day).    But not alarming.  Should be natural to lose a bit around the edges between events (and though I haven't looked closely at the day-to-day forecast, I'm pretty sure we're "between events", given the huge gains yesterday).  Plus, the coverage is still great.  Just a teensy, tiny bit disappointing to see us take a small step back.  Hopefully, the next event sweeps through soon and hammers them.

 

We'll see... only two days (three days of reports, since they come out the day after) left in Week 42.  Not that Week 42 is magic... Week 41 and 43 correlate well (to U.S. winter temps) as well.  Week 42 is just when the relationship/correlation peaks (oddly, the peak correlation to the winter AO is Week 43, even though the peak correlation to temps is Week 42... to me, the end result - sensible weather - is most important; so, I key in on Week 42... but it's fair to continue paying close attention through Week 43 and to the end of October - which is only a little beyond Week 43; beyond that, November is virtually irrelevant).  Anyway, over the next two days, the GFS does project an increase in snow cover:

 

 

...but it's a little bit of a mixed bag and focused over the far western portion of the area of interest.  So, it'll be interesting to see what the actual numbers end up being.  I hope someone with access to the daily numerical data will post it on here (on Tuesday... the data issued that day, for Monday, will mark the end of Week 42).  Unfortunately, Rutgers doesn't give the numbers on the dailies; and they don't update the weeklies on a regular basis (they were supposed to change this a few years ago, as I inquired about this, but they never made the change)... they wait for the end of the first week that completes in the new month, then they update the monthly chart for the previous month AND all of the weeklies for that previous month.  So, we won't get the official Week 42 number from Rutgers until November 4th, or there about.  So, I'm hoping someone with the raw SCE data who processes it themselves (so they have the numerics) will post it here.

according to these maps, we gained a ton in one day

yesterday's map

 

 

this evening's map

 

[mitchnick]

Sea Ice is way above recent years too

[millwx]

according to these maps, we gained a ton in one day

yesterday's map

 

 

this evening's map

 

 

That's intriguing.  The Rutgers data is something of the Bible on this, but it shouldn't disagree with NOAA.  Also odd is the date.  I was going to just chalk it up to data delay (the Rutgers data did show a large increase TWO days ago).  BUT, you would usually put the DATA date on the image, NOT the posting date.  So, does NOAA already have the 19th processed?  That doesn't seem reasonable, since the 19th was BARELY even over, as of the time you posted this (in Z time; in local time, it's NOT over... but I assume they use Z time).  On the other hand, the increase seen in the maps (most notably in the west, towards Europe... though there is some elsewhere) is precisely in line with the model projections for today (which is almost over) and tomorrow showed.  A little confusing.  The Rutgers update may provide clarity if there is an increase in their update tomorrow which matches the maps you posted (thanks for sharing them; I don't often go to this site... I rely on Rutgers, despite their lower res data).  My suspicion... we will see that increase on Rutgers tomorrow.  Why?  The polar orbiting satellites, with their microwave instruments (can see through clouds), provide much of the data for snow and ice.  Depending on the timing of the orbit, all NHEM data may be available prior to midnight (Z time).  So, it's possible the image can be produced prior to the day ending (perhaps well prior).

 

I really don't like leaning on single day fluctuations (hard to imagine how one day's snow/melt is going to impact U.S. weather).  But as the saying goes, it is what it is.  Each day affects the total.  So, any day-on-day increases are good to see.

 

Again, thanks for posting this.  Makes me curious to see what the Rutgers site is going to show tomorrow.  I *suspect* we'll see positive gains similar to the maps you posted.

 

(Note:  I kinda went on ad nauseam without even mentioning up front the date issue.  The dates being compared in the link from my post are 10/18 and 10/17.  That's when the slight snow loss occurred.  The dates on the images you posted for comparison are 10/19 and 10/18.  Making the grand assumption that everyone's using the DATA date, as they should... you've posted brand new data, which will appear in Rutgers early tomorrow - 10/20 - when they post the 10/19 data.  That's what I *think* we'll see.  So, I don't think there's any discrepancy here... I *think* there's just new data - that you posted - since my earlier post.)

[GaWx]

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 updates 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! I'll feel that way if Oct. ends up near 19.5 msk or higher.