December Med/Long Range Discussion Part 2

[mdsnowlover]

According to article in wash post artic is 40-50 degrees above normal, can someone verify that please??

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[mitchnick]

3 minutes ago, mdsnowlover said:

According to article in wash post artic is 40-50 degrees above normal, can someone verify that please??

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Could be. 6z gfs initialized this

[Yeoman]

37 minutes ago, mdsnowlover said:

According to article in wash post artic is 40-50 degrees above normal, can someone verify that please??

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fake news story - check Breitbart for the truth

http://bfy.tw/93ve

I can't believe people are this lazy and/or stupid

[Yeoman]

34 minutes ago, mitchnick said:

Could be. 6z gfs initialized this

Holy massive +NAO.. even the temp anomalies resemble a vortex

[midatlanticweather]

 

[WinterWxLuvr]

24 minutes ago, midatlanticweather said:

 

Pretty hard to take these Euro humpers seriously.

Both models came to basically the same conclusion with yesterday's 12z runs.

[psuhoffman]

At least things have improved enough to be worth talking about the guidance a bit again.  For several days it was nothing but ugly on EVERYTHING.  However, I am not getting carried away, if we were actually in a good pattern now looking at what were now seeing in the long range we would probably be less then excited.  But beggars can't be choosers so... My take on the full overnight runs is the long range continues to be more ambiguous then it was.  Ambiguous is good when the alternative was being locked into a god awful death pattern.  But make no mistake, the look shown on the long range GEFS and EPS is not great, just kinda meh.  The GGEM is actually still showing the god awful look but its also totally on its own around day 7-10 with some major changes that take place and by being off on that it remains locked into the pattern with no change in the long range.  Since the EPS and GEFS are now in agreement on the events a week out I am tossing the GGEM ensembles as I strongly feel they are late to the party here and are missing the pattern evolution completely. 

Both the GEFS and EPS pump a ridge into AK that helps a trough get into the east around day 7-10.  This is a new and encouraging development.  It wasnt showing up when it was out at long range and just kind of popped up around day 10.  This trough is transient as both the AK ridge and the WAR are a bit west and east respectively of where we need them to help lock in a cold pattern.  I have doubts about the ability to score a meaningful snow event from this period since we usually do better with second or third chances in a cold pattern and the trough being transient, unless we get perfect timing, its probably a rainstorm, cold, then warm up before anything else comes.  But the fact that this whole development was completely unseen when it was beyond day 10 is encouraging, both that the models may be totally off on some of the not so good features they still have in the long range, but also that the AK ridge seems to want to be a recurring feature this year.  While that alone wont guarantee anything it keeps us in the game and will help cold push south when it goes up. 

After this transient cold blast the models become less sure of what to do in the long range.  I actually like the EPS look a bit better, keeps the AK ridge stronger and is kind of neutral in the NAO domain.  By no means is it a good look but its not terrible either.  We would get some cold with that look but it would probably be transient and we would struggle to get storms not to cut without timing something up well.  Same old problems we are used to in a not ideal pattern.  Its workable at least, better then we were seeing the last week. 

My take is based on what were seeing in the guidance that perhaps this coming period is going to be more transient and volatile then the long term eastern ridge of death look we were getting before.  That is a definite step in the right direction.  What I am not seeing yet though is much evidence we are heading into a long term snow friendly pattern for us.  There are some things that seem to be showing themselves as trends this year that may be stable.  The WAR, AK ridge, strong PAC jet, and SE ridge.  Those 4 seem to be the most consistent features.  Given those might be the base state of this winter what I think is our best chance and what I am looking for is what the Para-GFS last night actually showed in the long range (see below).  I think if we keep those features all season the best way to beat down the SE ridge and offset the PAC jet will be to get either the AK Ridge to build up into the Arctic or the WAR to retrograde back into the NAO domain.  You get either to happen and you force the PV to drop down and then the other ridge will naturally fill the void and link up the two and suddenly we have a -NAO/-AO and a trough in the east.  The cold is there so it wouldn't that long to get into a good pattern either.  The Para GFS actually shows this, it pumps the AK ridge up and forces the PV out of its position, and towards the end you can clearly see the heights building in the NAO domain in response as the two ridges start to link up.  Basically get that PV to drop and the WAR will naturally retrograde in above it to fill the void.  I dont know that it will happen or when, but given the look we seem to have for this winter that series of events is our best bet to get a really good window for snow this winter.  That look on the long range PARA GFS is one that it would be hard for us to get out of without some snow.  I doubt it happens that fast, not much support for it yet, but I think it may be previewing what could happen at some point this winter.  Probably later in January or February. 

[Bob Chill]

Totally agree PSU. It's a crawl/walk then hopefully at some point run transition. Other than a mixed event, the d7-10 period isn't very promising. But we're moving from the shutout pattern were in now to one that would offer at least a chance at something. That is where my optimism comes from. It started feeling like a shutout pattern would dig in and drive us nuts for a long time. Considering the AK ridge just sorta popped up instead of being hinted at late in ens runs, there is no way to feel confident in making guesses as to what happens down the line. My guess is a slog in mediocrity and chasing flawed events for a while. I'm fine with that. Better than nothing I suppose. 

[Eskimo Joe]

Jan 6th is the start of the PA Farm Show...there's either a snow storm that week or one showing up within D5 on the models almost every year.  

[psuhoffman]

1 minute ago, Eskimo Joe said:

Jan 6th is the start of the PA Farm Show...there's either a snow storm that week or one showing up within D5 on the models almost every year.  

I wonder if the PA farm show is aware of their profound impact on the weather?

[WinterWxLuvr]

19 minutes ago, psuhoffman said:

At least things have improved enough to be worth talking about the guidance a bit again.  For several days it was nothing but ugly on EVERYTHING.  However, I am not getting carried away, if we were actually in a good pattern now looking at what were now seeing in the long range we would probably be less then excited.  But beggars can't be choosers so... My take on the full overnight runs is the long range continues to be more ambiguous then it was.  Ambiguous is good when the alternative was being locked into a god awful death pattern.  But make no mistake, the look shown on the long range GEFS and EPS is not great, just kinda meh.  The GGEM is actually still showing the god awful look but its also totally on its own around day 7-10 with some major changes that take place and by being off on that it remains locked into the pattern with no change in the long range.  Since the EPS and GEFS are now in agreement on the events a week out I am tossing the GGEM ensembles as I strongly feel they are late to the party here and are missing the pattern evolution completely. 

Both the GEFS and EPS pump a ridge into AK that helps a trough get into the east around day 7-10.  This is a new and encouraging development.  It wasnt showing up when it was out at long range and just kind of popped up around day 10.  This trough is transient as both the AK ridge and the WAR are a bit west and east respectively of where we need them to help lock in a cold pattern.  I have doubts about the ability to score a meaningful snow event from this period since we usually do better with second or third chances in a cold pattern and the trough being transient, unless we get perfect timing, its probably a rainstorm, cold, then warm up before anything else comes.  But the fact that this whole development was completely unseen when it was beyond day 10 is encouraging, both that the models may be totally off on some of the not so good features they still have in the long range, but also that the AK ridge seems to want to be a recurring feature this year.  While that alone wont guarantee anything it keeps us in the game and will help cold push south when it goes up. 

After this transient cold blast the models become less sure of what to do in the long range.  I actually like the EPS look a bit better, keeps the AK ridge stronger and is kind of neutral in the NAO domain.  By no means is it a good look but its not terrible either.  We would get some cold with that look but it would probably be transient and we would struggle to get storms not to cut without timing something up well.  Same old problems we are used to in a not ideal pattern.  Its workable at least, better then we were seeing the last week. 

My take is based on what were seeing in the guidance that perhaps this coming period is going to be more transient and volatile then the long term eastern ridge of death look we were getting before.  That is a definite step in the right direction.  What I am not seeing yet though is much evidence we are heading into a long term snow friendly pattern for us.  There are some things that seem to be showing themselves as trends this year that may be stable.  The WAR, AK ridge, strong PAC jet, and SE ridge.  Those 4 seem to be the most consistent features.  Given those might be the base state of this winter what I think is our best chance and what I am looking for is what the Para-GFS last night actually showed in the long range (see below).  I think if we keep those features all season the best way to beat down the SE ridge and offset the PAC jet will be to get either the AK Ridge to build up into the Arctic or the WAR to retrograde back into the NAO domain.  You get either to happen and you force the PV to drop down and then the other ridge will naturally fill the void and link up the two and suddenly we have a -NAO/-AO and a trough in the east.  The cold is there so it wouldn't that long to get into a good pattern either.  The Para GFS actually shows this, it pumps the AK ridge up and forces the PV out of its position, and towards the end you can clearly see the heights building in the NAO domain in response as the two ridges start to link up.  Basically get that PV to drop and the WAR will naturally retrograde in above it to fill the void.  I dont know that it will happen or when, but given the look we seem to have for this winter that series of events is our best bet to get a really good window for snow this winter.  That look on the long range PARA GFS is one that it would be hard for us to get out of without some snow.  I doubt it happens that fast, not much support for it yet, but I think it may be previewing what could happen at some point this winter.  Probably later in January or February. 

I like your post.  Good stuff.

I have to admit that I think the better pattern might happen faster than modeled.  3 days ago nothing looked even decent.  Once a glimmer appeared, it actually sped up by about 24 hours.  As you said, at first none of them saw much of anything beyond 10 days.  That kind of thing leaves open the possibility of even better things showing up. And worse. For whatever reason, I can't get the PSU site to load on my phone, but the gefs spaghetti plots show several solutions with the se ridge popping right back up after the day 9-10 period.

[psuhoffman]

13 minutes ago, WinterWxLuvr said:

I like your post.  Good stuff.

I have to admit that I think the better pattern might happen faster than modeled.  3 days ago nothing looked even decent.  Once a glimmer appeared, it actually sped up by about 24 hours.  As you said, at first none of them saw much of anything beyond 10 days.  That kind of thing leaves open the possibility of even better things showing up. And worse. For whatever reason, I can't get the PSU site to load on my phone, but the gefs spaghetti plots show several solutions with the se ridge popping right back up after the day 9-10 period.

Most of the GEFS members actually pop the SE ridge again, some of them tank the AO and lock the cold in but they are a minority.  However, the guidance has struggled beyond day 10 even more then usual and there is enough divergence in the members to think that period is still to be determined.  You may be right about things just popping up this year.  Things are very unstable and the models are struggling at range.  We are talking about some pretty major H5 features that need to move around though so I don't expect it to happen right in front of our face like day 1-5.  But I also think its very likely the guidance may not see it day 11-15 either.  This may not be something where we see the signs way out and have to wait for it to slowly develop.  The AK ridge could just decide to go gorilla all of a sudden day 7 and force a chain reaction that ends with a -AO and a good pattern.  It would be nice to have that happen rather then having to wait for it to slowly develop. 

[psuhoffman]

6z Para GFS does it again, goes ape with the AK ridge forcing PV to drop then links up with the higher heights from the WAR.  This look would be the beginning of a VERY good pattern.  While I doubt it happens this fast, its good that some sporadic runs of the guidance are showing it as that means the pattern does support it happening at some point. 

 

[Bob Chill]

I do like the GEFS but it's hard not to admit that it has been downright awful with the AO beyond d10 and the tendency to bust WAY low since late Nov is unmistakable. Until AN heights in the AO/NAO domain space start showing up inside of 10 days, the GEFS should mostly be ignored for HLB looks. 

[Prestige Worldwide]

45 minutes ago, Eskimo Joe said:

Jan 6th is the start of the PA Farm Show...there's either a snow storm that week or one showing up within D5 on the models almost every year.  

Is it near Carbondale?  If so lock in a big snowstorm now. 

[Bob Chill]

For S&G's...I can extrapolate a pretty good snowstorm. Transient well timed blocking and sprawling hp to our north...haha

 

 

 

 

[dallen7908]

Likely PA is different but other than 1996, I can't recall a big snow storm during that period. What storms are you referring to? 

[BTRWx]

What am I missing here?  To me, the Upper Midwest looks like two different scenarios from one run between 850mb and 2m...

[mappy]

is the midwest supposed to be colder than upper 20s? Your first map is saying it is up to +10 than normal. 

[nj2va]

12z GEFS continues pushing higher heights in the GOA beginning shortly after the new year.

[BTRWx]

14 minutes ago, mappy said:

is the midwest supposed to be colder than upper 20s? Your first map is saying it is up to +10 than normal. 

Exactly my point.  There's something awry going on between the two layers.

eta: As an example, Des Moines averages with a high of freezing on the 25th. https://www.wunderground.com/history/airport/KDSM/2016/12/25/DailyHistory.html?req_city=Des+Moines&req_state=IA&req_statename=&reqdb.zip=50321&reqdb.magic=6&reqdb.wmo=99999

[psuhoffman]

39 minutes ago, Bob Chill said:

For S&G's...I can extrapolate a pretty good snowstorm. Transient well timed blocking and sprawling hp to our north...haha

 

 

 

 

The end of the GFS op is perfectly acceptable.  It does nothing on the Atlantic side but it goes ape with the AK ridge to the point that it extends into western Canada and that would do the job just fine.  I also don't think its transient, if you loop the last 72 hours the ridge is still building in AK into northern Canada and if we roll that pattern forward its likely going to displace the PV further and eventually raise heights on the NAO side as well.   Of course we know things aren't going perfectly when we are extrapolating a day 16 prog. 

[BTRWx]

10 minutes ago, BTRWx said:

Exactly my point.  There's something awry going on between the two layers.

eta: As an example, Des Moines averages with a high of freezing on the 25th. https://www.wunderground.com/history/airport/KDSM/2016/12/25/DailyHistory.html?req_city=Des+Moines&req_state=IA&req_statename=&reqdb.zip=50321&reqdb.magic=6&reqdb.wmo=99999

The op shows an inversion at Des Moines, but gefs data would show it even stronger.  Odd.

[MN Transplant]

1 hour ago, BTRWx said:

What am I missing here?  To me, the Upper Midwest looks like two different scenarios from one run between 850mb and 2m...

 

 

I think you are just seeing an eroding cold airmass at the surface being overtaken slowly by warm air advection aloft.  Also, there is good snowcover right now, especially from northern IA and north.

[psuhoffman]

Euro day 10 leaves us in a pretty good pattern actually.  Again it is just one run of an op, but we are now seeing a lot of random runs showing the AO going negative either initiated by the AK ridge or in the case of the Euro from the WAR retrograding into Greenland.  Either works for us.  I still think this is probably rushing it, but it opens the slim chance that perhaps we do just slide right into this look quickly without much warning.  Have to see if support for it starts to show up in future runs and ensembles.  But to me the fact that numerous runs keep trying to get the PV out of its location and raise heights over the AO/NAO domain makes me think something in the pattern drivers wants to take us there and perhaps we will get there eventually if not sooner, later.  Thing's definitely look a lot better now then 48 hours ago. 

 

[BTRWx]

20 minutes ago, MN Transplant said:

 

I think you are just seeing an eroding cold airmass at the surface being overtaken slowly by warm air advection aloft.  Also, there is good snowcover right now, especially from northern IA and north.

Thanks, though I must question the bold. lol

[PaEasternWX]

1 hour ago, psuhoffman said:

Euro day 10 leaves us in a pretty good pattern actually.  Again it is just one run of an op, but we are now seeing a lot of random runs showing the AO going negative either initiated by the AK ridge or in the case of the Euro from the WAR retrograding into Greenland.  Either works for us.  I still think this is probably rushing it, but it opens the slim chance that perhaps we do just slide right into this look quickly without much warning.  Have to see if support for it starts to show up in future runs and ensembles.  But to me the fact that numerous runs keep trying to get the PV out of its location and raise heights over the AO/NAO domain makes me think something in the pattern drivers wants to take us there and perhaps we will get there eventually if not sooner, later.  Thing's definitely look a lot better now then 48 hours ago. 

 

Its nice to see the reds and blues in the right places.

[EastonSN+]

52 minutes ago, PaEasternWX said:

Its nice to see the reds and blues in the right places.

Would that negative PNA hurt us?

[Heisy]

Decent 18z GFS run for the LR. Not an amazing pattern or anything, but def something we could work with. 

[MAG5035]

1 hour ago, EastonSN+ said:

Would that negative PNA hurt us?

With that progged nice ridge that pokes up through Greenland and somewhat over the top of the pole a -PNA can certainly be workable and even successful, although that alignment would suggest to me storm potential of the northern branch or unphased variety vs any kind of major coastal development. It's definitely a cold look for sure, the northern Pac ridging would ensure the airmass source is an Arctic one coming into the US. Lose that Greenland ridge though and you allow the western trough to rise heights more in the east (SE ridge) and make the Mid-Atlantic vulnerable to cutters or being on the wrong side of the gradient when a storm comes along.