December 2017 Mid-Long Range Disco 2

[clskinsfan]

3 minutes ago, losetoa6 said:

I think the Gfs has shown flakes on Christmas for at least 4 or 5 runs in a row in parts of the  sub forum . Hope to see 12z continue that theme . 

Actually 6 runs have dusted some part of the sub forum 

Yep. It has shown snow for us westerners for days. But this run is way better for us and for everyone else as well.

[Interstate]

8 minutes ago, clskinsfan said:

Yep. It has shown snow for us westerners for days. But this run is way better for us and for everyone else as well.

This is a setup for you to get coal in your stocking if you live east of the fall line

[frd]

For those who know more about the MJO , here is what JB posted,  but I thought you require more amplitude to get an effect?  Is that true ??

The plot forecast shows a favorable phase but to me it looks a little weak and close to the COD

 

[Bob Chill]

14 minutes ago, frd said:

This is exactly what I saw when I viewed the maps DT had on his updated pod cast. Seems like a reload around the turn of the Year.

Bob, are you seeing what DT described , as some indications of higher hieghts building over Northern Greenland and even signs of a - AO developing the end of the year?

He stated a very dry last week of the year, but maybe indications of sometihng with the next front ( and wave ) towards the end of the year.   

Certainly the MJO increases the odds of an event I would think. I read as well , there may be up to a  10 day lag for the favorable phase of the MJO lead to a snow event in our general local. 

No signs of a classic -ao or nao right now. What is showing on the height panels is the EPO ridge folding and pressing poleward so mathmatically it's probably showing a neutral or neg AO but it's not the kind that's stable. I see nothing promising on the atlantic side but the NAO is notoriously difficult to predict. My guess is it remains positive but that's only a guess. 

[frd]

2 minutes ago, Bob Chill said:

No signs of a classic -ao or nao right now. What is showing on the height panels is the EPO ridge folding and pressing poleward so mathmatically it's probably showing a neutral or neg AO but it's not the kind that's stable. I see nothing promising on the atlantic side but the NAO is notoriously difficult to predict. My guess is it remains positive but that's only a guess. 

DT had mentioned as well in the podcast that we would need at least a neutral NAO to be in the game. I know we can score with the big time negative EPO,  but I believe he was referring to a SECS or even a MECS. 

Thanks Bob  

[Interstate]

What happened to our mega GL Blocking?

[showmethesnow]

5 minutes ago, frd said:

For those who know more about the MJO , here is what JB posted,  but I thought you require more amplitude to get an effect?  Is that true ??

The plot forecast shows a favorable phase but to me it looks a little weak and close to the COD

 

Could be wrong but the way I am reading this is he is of the opinion that MJO will enter 1 and 2 before taking a nosedive into the COD vs. what it shows now when it just enters 8.

[CAPE]

7 minutes ago, Interstate said:

What happened to our mega GL Blocking?

The same thing that always happens when the models advertise a legit -NAO. We see a day or 2 of positive h5 heights near GL, then gone.

[clskinsfan]

9 minutes ago, Bob Chill said:

No signs of a classic -ao or nao right now. What is showing on the height panels is the EPO ridge folding and pressing poleward so mathmatically it's probably showing a neutral or neg AO but it's not the kind that's stable. I see nothing promising on the atlantic side but the NAO is notoriously difficult to predict. My guess is it remains positive but that's only a guess. 

I dont know if I am allowed to paste images from Pivotal. So I wont. But if you want to see the crazy EPO ridge Bob is talking about check out this link. Talk about a squeeze play:

http://www.pivotalweather.com/model.php?m=gfs&p=500h_anom&rh=2017121906&fh=144&r=na&dpdt=

[clskinsfan]

4 minutes ago, showmethesnow said:

Could be wrong but the way I am reading this is he is of the opinion that MJO will enter 1 and 2 before taking a nosedive into the COD vs. what it shows now when it just enters 8.

The forecast is WAY better than it was just a week ago though. It wasnt even making it into 8 then. So who knows where it goes from here.

[cae]

7 minutes ago, clskinsfan said:

I dont know if I am allowed to paste images from Pivotal. So I wont. But if you want to see the crazy EPO ridge Bob is talking about check out this link. Talk about a squeeze play:

http://www.pivotalweather.com/model.php?m=gfs&p=500h_anom&rh=2017121906&fh=144&r=na&dpdt=

Pivotal is a free site, so I think it should be OK.  Here's the image.

ETA:  From Pivotal's web site:  "To share this GIF, please download it first and then distribute it elsewhere."  So they're OK with it as long as you copy it to somewhere else and don't hotlink it from their server.

[pasnownut]

8 minutes ago, clskinsfan said:

The forecast is WAY better than it was just a week ago though. It wasnt even making it into 8 then. So who knows where it goes from here.

yeah its not a strong signal, but it also doesnt appear to be "nosediving" into COD either.  From what I remember reading in the past, too strong in favorable phase can be overwhelming cold.  I think Bob/Mitch or redtaggers can confirm.

 

[psuhoffman]

1 minute ago, pasnownut said:

yeah its not a strong signal, but it also doesnt appear to be "nosediving" into COD either.  From what I remember reading in the past, too strong in favorable phase can be overwhelming cold.  I think Bob can confirm.

 

The correlation isn't precise enough to get that detailed about it.  Yes the stronger the wave the more influence it should have.  But the MJO can also have more/less influence based on other factors and what is driving the pattern.  Its not a universal correlation, nothing is, if it was this whole prediction thing would be easy.  But I would say we want the wave to be amplified enough to stay out of the COD as it goes through our money phases of 8/1.  Beyond that details aren't worth parsing.  

[poolz1]

12 minutes ago, showmethesnow said:

Could be wrong but the way I am reading this is he is of the opinion that MJO will enter 1 and 2 before taking a nosedive into the COD vs. what it shows now when it just enters 8.

I think the point of his post was to note NOAA's Line that stated the possibility of a bias toward the warm phases...A stronger 8 & 1 would be the result.  

[pasnownut]

2 minutes ago, poolz1 said:

I think the point of his post was to note NOAA's Line that stated the possibility of a bias toward the warm phases...A stronger 8 & 1 would be the result.  

8/1 are not warm in the east.  I'm confused.  

No digs on showme, just pointing out MJO plots show transition to 8/1 and not taking a hard left into COD.  No biggie, and regardless...it will look different all too soon.

 

[Bob Chill]

I keep bringing up 93-94, 13-14, and 14-15 but I can't find a better match for how winter has behaved so far. All EPO driven winters. We did have a -AO for a time this year but the NAO never cooperated. I put together some quick epo graphs for NJDF for those three year as well as Nov-Dec month to date. 

ND MTD:

 

Current progs tank the EPO again basically right now and keep it strongly there through the end of the ens runs. My guess is it lasts into January for a time at least. It's hard to deny the negative tendency for the EPO this year and it started in November. EPS D10-15 mean shows an very strong signal for a -EPO through the end of the run:

 

 

 

How does this year compare to the 3 analogs? All 3 also started in Nov but had variances in the peaks and valleys

 

93-94 NDJF

 

^ You can easily see reason for the big arctic outbreak in January. Until that point the EPO had a negative tendency but not as strong as what we're seeing so far this year. 

 

13-14 NDJF

 

^ Dec started cold but we all remember the epic warmth mid month before the reload and fun and games. The warm/cold periods of 13-14 were directly tied to the EPO and the EPO was the ONLY reason (other than lucky) for an epic winter. 

 

14-15 NJDF

 

^ This winter didn't really start until mid Feb. We had solid cold periods before that but we couldn't get a storm track right to save our life. lol. When the EPO flipped from + to - in mid Feb it was the harbinger of a pretty incredible late season. 

 

The EPO itself is a bad indicator for snow because other things are more important however, it's a good indicator of cold dumping into the conus. I would much prefer getting a -AO/NAO to deliver but if we aren't going to get that then the next best thing is the EPO working in our favor. I would have to dig through a ton of data to make a more educated guess but it seems that winters with a prominent and effective -EPO show their hand in November. This year is no exception and it's behaving differently than other years. We'll see how the second half of Dec looks after it's done but I expect the ND EPO graph to be heavy on the negative side with the lowest readings during the last 10 days of the month. 

 

 

[pasnownut]

2 minutes ago, Bob Chill said:

I keep bringing up 93-94, 13-14, and 14-15 but I can't find a better match for how winter has behaved so far. All EPO driven winters. We did have a -AO for a time this year but the NAO never cooperated. I put together some quick epo graphs for NJDF for those three year as well as Nov-Dec month to date. 

ND MTD:

 

Current progs tank the EPO again basically right now and keep it strongly there through the end of the ens runs. My guess is it lasts into January for a time at least. It's hard to deny the negative tendency for the EPO this year and it started in November. EPS D10-15 mean shows an very strong signal for a -EPO through the end of the run:

 

 

 

How does this year compare to the 3 analogs? All 3 also started in Nov but had variances in the peaks and valleys

 

93-94 DJFM

 

^ You can easily see reason for the big arctic outbreak in January. Until that point the EPO had a negative tendency but not as strong as what we're seeing so far this year. 

 

13-14 NDJF

 

^ Dec started cold but we all remember the epic warmth mid month before the reload and fun and games. The warm/cold periods of 13-14 were directly tied to the EPO and the EPO was the ONLY reason (other than lucky) for an epic winter. 

 

14-15 NJDF

 

^ This winter didn't really start until mid Feb. We had solid cold periods before that but we couldn't get a storm track right to save our life. lol. When the EPO flipped from + to - in mid Feb it was the harbinger of a pretty incredible late season. 

 

The EPO itself is a bad indicator for snow because other things are more important however, it's a good indicator of cold dumping into the conus. I would much prefer getting a -AO/NAO to deliver but if we aren't going to get that then the next best thing is the EPO working in our favor. I would have to dig through a ton of data to make a more educated guess but it seem that winters with a prominent and effective -EPO show their hand in November. This year is no exception and it's behaving differently than other years. We'll see how the second half of Dec looks after it's done but I expect the ND EPO graph to be heavy on the negative side with the lowest readings during the last 10 days of the month. 

 

 

Great stuff Bob.  For an "amateur", you sure can sling it w/ the best of em...

I realize a lot more digging required, but i'd love to know what caused the "pseudo -NAO" stuff we all thought was finally happening a couple weeks ago, from materializing?  I'd take your "un"educated guess...if you have one.  It baffles me as its been a false indicator so so many times in the last few years.

Nut

[poolz1]

15 minutes ago, pasnownut said:

8/1 are not warm in the east.  I'm confused.  

No digs on showme, just pointing out MJO plots show transition to 8/1 and not taking a hard left into COD.  No biggie, and regardless...it will look different all too soon.

 

Correct, 8 and 1 are not warm in the east.  Maybe my wording was confusing..The way I read it was that NOAA feels there could be a bias in the run toward the COD or warm phases which would result in the forecast eventually correcting toward more amplification in 8 - 1 - 2.  

[BTRWx's Thanks Giving]

3 minutes ago, poolz1 said:

Correct, 8 and 1 are not warm in the east.  Maybe my wording was confusing..The way I read it was that NOAA feels there could be a bias in the run toward the COD or warm phases which would result in the forecast eventually correcting toward more amplification in 8 - 1 - 2.  

That's possible.  Almost all long-range signals have been chaotic.  Anyone have an open-source link to ecm plumes for the MJO?

[pasnownut]

Just now, poolz1 said:

Correct, 8 and 1 are not warm in the east.  Maybe my wording was confusing..The way I read it was that NOAA feels there could be a bias in the run toward the COD or warm phases which would result in the forecast eventually correcting toward more amplification in 8 - 1 - 2.  

All good.  Thats better.  Now i got you. 

Anxious to see what the 12z's are serving up for lunch.

 

[yoda]

06z GFS also came up with a nice winter event for the 30th-31st... 24 hrs of snow thanks to a strong HP in Quebec of 1045+

[psuhoffman]

21 minutes ago, Bob Chill said:

I keep bringing up 93-94, 13-14, and 14-15 but I can't find a better match for how winter has behaved so far. All EPO driven winters. We did have a -AO for a time this year but the NAO never cooperated. I put together some quick epo graphs for NJDF for those three year as well as Nov-Dec month to date. 

ND MTD:

 

Current progs tank the EPO again basically right now and keep it strongly there through the end of the ens runs. My guess is it lasts into January for a time at least. It's hard to deny the negative tendency for the EPO this year and it started in November. EPS D10-15 mean shows an very strong signal for a -EPO through the end of the run:

 

 

 

How does this year compare to the 3 analogs? All 3 also started in Nov but had variances in the peaks and valleys

 

93-94 DJFM

 

^ You can easily see reason for the big arctic outbreak in January. Until that point the EPO had a negative tendency but not as strong as what we're seeing so far this year. 

 

13-14 NDJF

 

^ Dec started cold but we all remember the epic warmth mid month before the reload and fun and games. The warm/cold periods of 13-14 were directly tied to the EPO and the EPO was the ONLY reason (other than lucky) for an epic winter. 

 

14-15 NJDF

 

^ This winter didn't really start until mid Feb. We had solid cold periods before that but we couldn't get a storm track right to save our life. lol. When the EPO flipped from + to - in mid Feb it was the harbinger of a pretty incredible late season. 

 

The EPO itself is a bad indicator for snow because other things are more important however, it's a good indicator of cold dumping into the conus. I would much prefer getting a -AO/NAO to deliver but if we aren't going to get that then the next best thing is the EPO working in our favor. I would have to dig through a ton of data to make a more educated guess but it seems that winters with a prominent and effective -EPO show their hand in November. This year is no exception and it's behaving differently than other years. We'll see how the second half of Dec looks after it's done but I expect the ND EPO graph to be heavy on the negative side with the lowest readings during the last 10 days of the month. 

 

 

It seems lately that getting cold has been by far our bigger issue vs precip.  Typically if we get sustained cold we end up doing good.  I am not talking about some 5 day hit and run cold, but in recent winters where we get a long duration period or periods of cold eventually we score.  I wonder if the EPO isnt becoming more important for snow then it was since a cold/non snowy winter seems very rare in the last 30 years or so.   Our cold periods typically are snowy now also.  So getting a sustained -EPO that keeps us on the cold side might correlate with snowfall more then it did historically given the recent trends.  Just thinking out loud but it seems the last few times we got epo help it worked very well and so far the results have been good this year.  This could all be total luck but perhaps the long term pattern has something to do with it also.  

[Bob Chill]

8 minutes ago, psuhoffman said:

It seems lately that getting cold has been by far our bigger issue vs precip.  Typically if we get sustained cold we end up doing good.  I am not talking about some 5 day hit and run cold, but in recent winters where we get a long duration period or periods of cold eventually we score.  I wonder if the EPO isnt becoming more important for snow then it was since a cold/non snowy winter seems very rare in the last 30 years or so.   Our cold periods typically are snowy now also.  So getting a sustained -EPO that keeps us on the cold side might correlate with snowfall more then it did historically given the recent trends.  Just thinking out loud but it seems the last few times we got epo help it worked very well and so far the results have been good this year.  This could all be total luck but perhaps the long term pattern has something to do with it also.  

I think in the absence of traditional atlantic or arctic blocking, the EPO is probably the next thing in line to help us out. PNA is important too without blocking. Since the PNA/EPO regions share a little space, there is a correlation with a +PNA and -EPO from what I've seen but I haven't looked too hard. 

 

Another thing I've been pondering is whether or not a -AO/EPO/NAO can co-exist. That's an awful lot of real estate for HP to cover. Basically from one side of the arctic circle to the other. My guess is a -EPO correlates with at least a +NAO. The AO is closer to the EPO region so when an EPO ridge presses poleward it becomes a quasi or bootleg -AO at times. We've seen that before. 

[Bob Chill]

One thing all models are backing down on is the amplitude of the pre-christmas cutter. GFS is coming in more sheared with a flatter solution again. SNE could end up with a nice snow event. Not sure what it means down the line but short term hasn't been very accurate with this pattern flip. 

[Bob Chill]

6 run MSLP trend gif shows it well. HP to the N-NE is winning a small battle here. 

[WxUSAF]

8 minutes ago, Bob Chill said:

One thing all models are backing down on is the amplitude of the pre-christmas cutter. GFS is coming in more sheared with a flatter solution again. NNE could end up with a nice snow event. Not sure what it means down the line but short term hasn't been very accurate with this pattern flip. 

Well it’s not so much the amplitude, at least with this run. 990mb over Detroit at 12z on the 23rd. But yeah that ridge to the NE is stronger.

[Bob Chill]

1 minute ago, WxUSAF said:

Well it’s not so much the amplitude, at least with this run. 990mb over Detroit at 12z on the 23rd. But yeah that ridge to the NE is stronger.

Just a few days ago, euro/gfs agreed on a phased lead wave running a ridge but that has morphed to a sheared lead wave running into a bit of confluence. Now the trailing wave is amping up so it looks the same in the end but how it gets there is different. What sort of short term trends happen with the trailing wave now? This pattern is driving the models a bit crazy. For our sensible wx, it's much easier. We're getting rain until the front clears. Different story up north of us. 

[SomeguyfromTakomaPark]

GFS looks to have sped the front up again pretty significantly through 126.

[Heisy]

The 12z GFS looks way better thus far, wow!

[Bob Chill]

Just now, DCTeacherman said:

GFS looks to have sped the front up again pretty significantly through 126.

Trough more neutral instead of very positive through 120 as well. It's a small but sig change if we want to get on the cold side faster.