January Medium/Long Range Disco Thread

[Vice-Regent]

6 minutes ago, CAPE said:

The -NAO with a horrid Pac isn't likely to make many people happy, so..

The other interesting thing with the advertised +heights over Baffin in the LR- and this is being debated in the NE forum- is that it may be the result of mild Pac air flow across Canada, warming and expanding the column, and producing those anomalous 500 mb heights, vs an actual ridge(anticyclone) which should have an adjacent trough over the east. I am not sure if I buy that, but there doesn't seem to be much curvature to the height lines once the +heights move into the sweet spot. I think that is probably more an artifact of a smoothed mean 15 days out. Either way, the PAC needs to become less hostile going forward or we will likely continue to struggle for chances of frozen.

[aldie 22]

Just now, leesburg 04 said:

bootleg

get it....get it....GET IT!!!

[CAPE]

Just now, leesburg 04 said:

bootleg

I think we had one of those in Jan 2016.

[Ji]

this might be the most disheartning. Our #1 teleconnection for snow is a -AO.  

 

[CAPE]

2 minutes ago, Vice-Regent said:

Retro the trough and get an EPO ridge(or coupled +PNA/-EPO) and we can shut off that firehose.

[aldie 22]

1 minute ago, Ji said:

this might be the most disheartning. Our #1 teleconnection for snow is a -AO.  

 

Have you planned your epic meltdown or are you just going to wing it?

[psuhoffman]

1 hour ago, CAPE said:

Extended GEFS has the look we need to flush the Pac puke and inject legit cold into our source region. Hopefully we get there, but it will take some time.

eta- h5 is actually much improved out west by mid Jan, but still relatively mild in the lower levels at that time.

This post isn’t specific to our snow chances. So hopefully everyone won’t freak out.  It can still get cold enough to snow. That temp profile would probably work. Barely. Let’s also assume (because it’s scary not too) that is skewed a bit warm by some outliers. But what’s scary is that is literally the perfect pattern for us to be cold. Look at our source region...straight off the North Pole. The coldest anomalies in the northern Hemisphere are over N America and it’s weak sauce. Mostly -2 to -4 stuff. That’s it. And even that is bottled up on the Canadien prairie without the depth needed to press and spread southeast. @cbmclean pointed out how Asia and Europe have been cold, but their cold source is different. Siberia is a huge land locked high latitude region that is perfect to build deep cold. It’s one thing to see cold there.  But even when we get cross polar flow on guidance and the “cold” shifts to our side...it’s not really cold.  I’ve been watching this for a while and I’d like to see some evidence we can still build true deep arctic airmasses over North America without that once in a blue moon direct shot from Russia. And even then it seems to moderate quickly once out of the Siberian cold seeding grounds. 

[North Balti Zen]

My favorite is gonna be when there finally is a change and some cold gets here that we are told it will be another few weeks beyond that before we have a chance as the first few systems after said change pass to the northwest still and will be needed to “get things right” and that when the storm after the storm after the storm gets here the spacing won’t be right and piece of energy will act as kicker to boot storm off the coast then pattern will re-shuffle and then it is March and the parts of the forum that live with mountain goats tell us March 25 snow is at hand while it rains sideways off an east wind as true blocking finally kicks in and stays until may 20.

[Ralph Wiggum]

14 minutes ago, Ji said:

this might be the most disheartning. Our #1 teleconnection for snow is a -AO.  

 

This is why I'm not a fan of numeric indices. They don't give the true story of what is happening wrt real weather at the surface. We would have looked at that chart if it were a prog outlook before the season and assumed wall to wall cold and most would have had warning criteria snows by now. Not even remotely the case.

[Ralph Wiggum]

1 minute ago, North Balti Zen said:

My favorite is gonna be when there finally is a change and some cold gets here that we are told it will be another few weeks beyond that before we have a chance as the first few systems after said change pass to the northwest still and will be needed to “get things right” and that when the storm after the storm after the storm gets here the spacing won’t be right and piece of energy will act as kicker to boot storm off the coast then pattern will re-shuffle and then it is March and the parts of the forum that live with mountain goats tell us March 25 snow is at hand while it rains sideways off an east wind as true blocking finally kicks in and stays until may 20.

Is the period broken on your keyboard? 

[aldie 22]

6 minutes ago, psuhoffman said:

This post isn’t specific to our snow chances. So hopefully everyone won’t freak out.  It can still get cold enough to snow. That temp profile would probably work. Barely. Let’s also assume (because it’s scary not too) that is skewed a bit warm by some outliers. But what’s scary is that is literally the perfect pattern for us to be cold. Look at our source region...straight off the North Pole. The coldest anomalies in the northern Hemisphere are over N America and it’s weak sauce. Mostly -2 to -4 stuff. That’s it. And even that is bottled up on the Canadien prairie without the depth needed to press and spread southeast. @cbmclean pointed out how Asia and Europe have been cold, but their cold source is different. Siberia is a huge land locked high latitude region that is perfect to build deep cold. It’s one thing to see cold there.  But even when we get cross polar flow on guidance and the “cold” shifts to our side...it’s not really cold.  I’ve been watching this for a while and I’d like to see some evidence we can still build true deep arctic airmasses over North America without that once in a blue moon direct shot from Russia. And even then it seems to moderate quickly once out of the Siberian cold seeding grounds. 

So do you really think some on here won't freak out?

[CAPE]

16 minutes ago, psuhoffman said:

This post isn’t specific to our snow chances. So hopefully everyone won’t freak out.  It can still get cold enough to snow. That temp profile would probably work. Barely. Let’s also assume (because it’s scary not too) that is skewed a bit warm by some outliers. But what’s scary is that is literally the perfect pattern for us to be cold. Look at our source region...straight off the North Pole. The coldest anomalies in the northern Hemisphere are over N America and it’s weak sauce. Mostly -2 to -4 stuff. That’s it. And even that is bottled up on the Canadien prairie without the depth needed to press and spread southeast. @cbmclean pointed out how Asia and Europe have been cold, but their cold source is different. Siberia is a huge land locked high latitude region that is perfect to build deep cold. It’s one thing to see cold there.  But even when we get cross polar flow on guidance and the “cold” shifts to our side...it’s not really cold.  I’ve been watching this for a while and I’d like to see some evidence we can still build true deep arctic airmasses over North America without that once in a blue moon direct shot from Russia. And even then it seems to moderate quickly once out of the Siberian cold seeding grounds. 

It does get some -6 to -10 up there a few days later. Outside of something dramatic happening as a result of the SWE, we will probably have to make do with moderate cold.

[aldie 22]

6 minutes ago, CAPE said:

It does get some -6 to -10 up there a few days later. Outside of something dramatic happening as a result of the SWE, we will probably have to make do with moderate cold.

It's 8 degrees in Minneapolis

[psuhoffman]

53 minutes ago, CAPE said:

The -NAO with a horrid Pac isn't likely to make many people happy, so..

The other interesting thing with the advertised +heights over Baffin in the LR- and this is being debated in the NE forum- is that it may be the result of mild Pac air flow across Canada, warming and expanding the column, and producing those anomalous 500 mb heights, vs an actual ridge(anticyclone) which should have an adjacent trough over the east. I am not sure if I buy that, but there doesn't seem to be much curvature to the height lines once the +heights move into the sweet spot. I think that is probably more an artifact of a smoothed mean 15 days out. Either way, the PAC needs to become less hostile going forward or we will likely continue to struggle for chances of frozen.

I am with Webb on this.  The look being thrown out there...west based NAO with a trough west of SW of AK is our best snow look. It’s the most common look that came up when I studied every warning event.  Without a block the trough in the north Pac would be a death sentence. But historically a -NAO has been plenty able to offset that and essentially what we get is all that pac energy crashing into the CONUS and being forced under the blocking with just enough cold. It’s not a cold look. Most of our snowiest periods were barely cold enough to snow.  Frankly everyone wishing for these pac patterns that lead to arctic outbreaks...that’s NOT our snow look. That’s a cold dry warm wet look absent blocking. 80% of our snow comes in “barely cold enough to snow” blocking patterns with domestic cold sources.  Yes getting a big huge epo ridge and a -NAO would be great...and some guidance even suggests that’s possible, but that’s also super rare. When you have a ridge on the NAO side there is usually going to be a trough on the Pac side. That’s basic wave physics. Only in rare instances where the TPV has been completely obliterated (and this year might end up that) can you get a ridge across the whole northern Hemisphere high latitudes. If that’s what we need to snow now...well I’d like to believe that’s not true. 
 

We already need so many moving parts to go right. But there will always be this one other thing we could point to and say “well that isn’t perfect” but imo keeping it real that look SHOULD work.  I’m not saying it won’t.  I think models are underplaying the cold.  And HM pointed out the cold usually lags the SSW by 20 days.  He also showed a graphic that clearly shows the warmth surge into the eastern US around the time of the SSW supporting the hypothesis we talked about yesterday.  We probably just have to be patient.  But in the end if we get a west based block I’m not going to just dismiss its failure as “well the pac” because in the past the pac look we have now was just fine with a -NAO!  

As for your second point wrt #bootleg I agree. I touched on this last night.  I do think there is some truth to that point in that the warmth is biasing the NWP towards higher heights. But there is ample evidence it’s not just that.  When you look at individual runs of OPs and control runs there is legit ridging and even a Rex block at times.  So why are we to believe the ensembles have the same height pattern but not the blocking?   Furthermore, at that range those are some crazy anomalies to explain fully by warmth. Lastly the pattern around wouldn’t fit. If that was totally due to pac warmth you would see a wave 1 look with a full latitude trough in the pac and a full latitude ridge in eastern N America. We do see that for a time when the NAO is east based and more of a WAR. But once it retrogrades suddenly you see a trough migrate east under the blocking. You wouldn’t see that if it was bootleg with that pac. And like you said smoothing at that range will mute the lines.  At a specific time members have the ridge centered over Hudson Bay, some Baffin, some Davis, some Greenland. Timing and location differences will smooth out details.   I respect their hypothesis and the one piece of evidence to support that theory is the pathetic temp response to the blocking however that can be explained in other ways (the temp base state on our side of the globe is just horrid right now) and the preponderance of all other evidence doesn’t support that conclusion imo. 
 

ETA: what made 2014 and 2015 work were rare oddities. A huge full latitude positively tilted EPO PNA ridge in 2014 and a crazy displaced TPV in 2015. Those were super rare and not typical ways we snow. I don’t want to rely on that 1/20 year type pattern to get snow. 

[WinterWxLuvr]

Cold will be less of issue once these aren’t the storm tracks ..

[Yeoman]

Bring on the pac puke!

[psuhoffman]

15 minutes ago, WinterWxLuvr said:

Cold will be less of issue once these aren’t the storm tracks ..

Yes but that’s a chicken or the egg argument. One of the reasons the storm track is so far north (even during periods with a half decent pattern) is the warmth.   Storms will ride the zone of best baroclinicity along the thermal boundary between subtropical air and polar air. When that boundary is up in Canada we’re screwed no matter what the steering currents are. 

[Kevin Reilly]

8 minutes ago, WinterWxLuvr said:

Cold will be less of issue once these aren’t the storm tracks ..

You forgot to draw in a big blue H off the coast of the Southeastern United States.  Time and time again the warmth is gathering in Texas off to the east and southeast deflecting the storms to follow a developed baroclinic zone west of the southeast ridge. 

[cbmclean]

37 minutes ago, psuhoffman said:

This post isn’t specific to our snow chances. So hopefully everyone won’t freak out.  It can still get cold enough to snow. That temp profile would probably work. Barely. Let’s also assume (because it’s scary not too) that is skewed a bit warm by some outliers. But what’s scary is that is literally the perfect pattern for us to be cold. Look at our source region...straight off the North Pole. The coldest anomalies in the northern Hemisphere are over N America and it’s weak sauce. Mostly -2 to -4 stuff. That’s it. And even that is bottled up on the Canadien prairie without the depth needed to press and spread southeast. @cbmclean pointed out how Asia and Europe have been cold, but their cold source is different. Siberia is a huge land locked high latitude region that is perfect to build deep cold. It’s one thing to see cold there.  But even when we get cross polar flow on guidance and the “cold” shifts to our side...it’s not really cold.  I’ve been watching this for a while and I’d like to see some evidence we can still build true deep arctic airmasses over North America without that once in a blue moon direct shot from Russia. And even then it seems to moderate quickly once out of the Siberian cold seeding grounds. 

Last sustained cold to affect me was late December 2017/early January 2018.  That was a legit cold period here, and I think up you guys way as well.  Not sure where it's source was.  Also, there was a pretty nice outbreak that hit the Midwest in Jan 2019, but never made it here.

[psuhoffman]

10 minutes ago, leesburg 04 said:

It's 8 degrees in Minneapolis

Yea that’s why I said this discussion is NOT about our our chances.  That look is cold enough to snow. But it’s annoying when any ridge brings +15 anomalies and under ideal perfect conditions the best a cold airmass can muster is -5. 

[Ji]

5 minutes ago, psuhoffman said:

Yes but that’s a chicken or the egg argument. One of the reasons the storm track is so far north (even during periods with a half decent pattern) is the warmth.   Storms will ride the zone of brew test baroclinicity along the thermal boundary between subtropical air and polar air. When that boundary is up in Canada we’re screwed no matter what the steering currents are. 

i always keep thinking about what you said about the extremely warm November we had and the recovery time it takes from such an occurence

[CAPE]

14 minutes ago, psuhoffman said:

I am with Webb on this.  The look being thrown out there...west based NAO with a trough west of SW of AK is our best snow look. It’s the most common look that came up when I studied every warning event.  Without a block the trough in the north Pac would be a death sentence. But historically a -NAO has been plenty able to offset that and essentially what we get is all that pac energy crashing into the CONUS and being forced under the blocking with just enough cold. It’s not a cold look. Most of our snowiest periods were barely cold enough to snow.  Frankly everyone wishing for these pac patterns that lead to arctic outbreaks...that’s NOT our snow look. That’s a cold dry warm wet look absent blocking. 80% of our snow comes in “barely cold enough to snow” blocking patterns with domestic cold sources.  Yes getting a big huge epo ridge and a -NAO would be great...and some guidance even suggests that’s possible, but that’s also super rare. When you have a ridge on the NAO side there is usually going to be a trough on the Pac side. That’s basic wave physics. Only in rare instances where the TPV has been completely obliterated (and this year might end up that) can you get a ridge across the whole northern Hemisphere high latitudes. If that’s what we need to snow now...well I’d like to believe that’s not true. 
 

We already need so many moving parts to go right. But there will always be this one other thing we could point to and say “well that isn’t perfect” but imo keeping it real that look SHOULD work.  I’m not saying it won’t.  I think models are underplaying the cold.  And HM pointed out the cold usually lags the SSW by 20 days.  He also showed a graphic that clearly shows the warmth surge into the eastern US around the time of the SSW supporting the hypothesis we talked about yesterday.  We probably just have to be patient.  But in the end if we get a west based block I’m not going to just dismiss its failure as “well the pac” because in the past the pac look we have now was just fine with a -NAO!  

 

Not sure those composites necessarily match what we have going on now all that well. Sure they are close at first glance. The one on the left implies a PNA ridge and the one on the right has some ridging in the EPO/WPO domain. Also hard to gauge the strength of the NE PAC trough, and what may be different impacts from ENSO background state, ocean temp anomalies, and Pac jet strength/ position now vs using 10+ year old analogs.

[psuhoffman]

10 minutes ago, Ji said:

i always keep thinking about what you said about the extremely warm November we had and the recovery time it takes from such an occurence

I do think that is a huge part of this. Even more then simply base state warming.  We are a month behind in generating cold in our source regions. Plus we flipped right from that horrid (really was maybe the worst November into early December EVER) to a high latitude ridging pattern that locked in that puke airmass meaning the cold on our side has to develop mostly on its own without an infusion from Asia. And while the pattern has been better since there have still been periodic episodes of pacific maritime intrusion to delay the process. So in a way we still have a N American thermal profile more indicative of late fall not going into January. 

[PivotPoint]

3 hours ago, Ralph Wiggum said:

January of which year? 2022?

I've never seen guidance track so many ull and surface lows to our South and yield rain to SE Canada during prime climo with such a distinct west-based NAO in my 30 years of tracking. New Englanders must be jumping from bridges. At least we are used to regularly failing down this way.

 

1 hour ago, CAPE said:

The -NAO with a horrid Pac isn't likely to make many people happy, so..

The other interesting thing with the advertised +heights over Baffin in the LR- and this is being debated in the NE forum- is that it may be the result of mild Pac air flow across Canada, warming and expanding the column, and producing those anomalous 500 mb heights, vs an actual ridge(anticyclone) which should have an adjacent trough over the east. I am not sure if I buy that, but there doesn't seem to be much curvature to the height lines once the +heights move into the sweet spot. I think that is probably more an artifact of a smoothed mean 15 days out. Either way, the PAC needs to become less hostile going forward or we will likely continue to struggle for chances of frozen.

Lesson learned from this year: stable and early in the season blocking can screw us... badly. The issue here for winter weather this season is simple. Our source region had no time to build up cold and the PAC has a mean trough look. Pretty simple actually. There’s other side dishes in there but the meat and potatoes is there is no cold within 2000 miles to our N/NW. -5, -10 temp anomalies in central Canada have people saying “that’s cold enough for snow”. Well, yes. For them though, not for us. By the time that airmass were to reach us it would be modified and mixed to the degree that it would not support snow down here in the mid Atlantic. The only way to help fox our source region this late in the game would be a SSWE, or perhaps an EPO ridge and +NAO combo that allows cold to build back up for 4-5 weeks, then we hope for a cold March. It’s becoming pretty clear to me that any major snow chances might be a real outside chance (again) this year. I think we’ll probably luck into some times front that has some trailing energy to allow enough cold drainage for snow, but there’s a real chance that NOVA/DC metro gets blanked. Even if it does snow I bet we have surface temp galore problems not having any juice behind an artic high or even a modified front. Not feeling warm and fuzzy about our chances through foreseeable future. Maybe mid feb-March will produce.

[psuhoffman]

34 minutes ago, CAPE said:

Not sure those composites necessarily match what we have going on now all that well. Sure they are close at first glance. The one on the left implies a PNA ridge and the one on the right has some ridging in the EPO/WPO domain. Also hard to gauge the strength of the NE PAC trough, and what may be different impacts from ENSO background state, ocean temp anomalies,, and Pac jet strength/ position now vs using 10+ year old analogs.

I was comparing them to the projected looks in mid January. Looks close enough to me. 
GEFS and EPS extended 

What I was talking about was the fact people are saying even that look is no good and why it’s still warm on the long range guidance. Now if that look never comes this is moot. But that  look is actually a great snow look historically. That’s all I’m saying. 

Your second point is interesting. The one biggest change is the enhanced pac jet. But that seems to be a new normal since it’s existed for quite a while now regardless of enso state.  But perhaps that has made that look less supportive then it once was. And your point about outdated analogs is true. But that also kind of feeds my point which summed up is “we better hope that look still works because it’s responsible for A LOT of our best snowstorms and it’s not like we’re picking up new ways to snow to replace it in this warmer climate base state”. 

[WinterWxLuvr]

42 minutes ago, psuhoffman said:

Yes but that’s a chicken or the egg argument. One of the reasons the storm track is so far north (even during periods with a half decent pattern) is the warmth.   Storms will ride the zone of brew test baroclinicity along the thermal boundary between subtropical air and polar air. When that boundary is up in Canada we’re screwed no matter what the steering currents are. 

If we are doing the chicken and egg thing then let’s talk about that Everest style mountain of heights off the east coast

[roardog]

If you watch the extended 2M temperature anomalies on a regular basis, you will see they have a huge warm bias on all of the models. Maybe in a mild pattern they might be ok but in a cold pattern, they’re always terrible. The models seem to do much better with the 850mb temp anomalies. I love it when it forecasts  a cold source region, well below normal 850 temp anomalies and above normal 2M temps. lol

[psuhoffman]

4 minutes ago, WinterWxLuvr said:

If we are doing the chicken and egg thing then let’s talk about that Everest style mountain of heights off the east coast

It’s all symbiotic. The way you knock that down is to get storms into that area. The wave break from those amplifying storms helps retrograde the ridge into the NAO domain. What derailed the last attempt to set off that chain reaction was the boundary ended to so far NW that storms cut and got stuck up in Canada. Never making it into the regions we need to set off the positive feedback cycle. 

[psuhoffman]

@CAPE but technically the long range guidance is starting to “hint” at a workable temp profile. This is the end of the GEFS. This should support what we need. 

[CAPE]

7 minutes ago, psuhoffman said:

I was comparing them to the projected looks in mid January. Looks close enough to me. 
GEFS and EPS extended 
 

What I was talking about was the fact people are saying even that look is no good and why it’s still warm on the long range guidance. Now if that look never comes this is moot. But that  look is actually a great snow look historically. That’s all I’m saying. 

Your second point is interesting. The one biggest change is the enhanced pac jet. But that seems to be a new normal since it’s existed for quite a while now regardless of enso state.  But perhaps that has made that look less supportive then it once was. And your point about outdated analogs is true. But that also kind of feeds my point which summed up is “we better hope that look still works because it’s responsible for A LOT of our best snowstorms and it’s not like we’re picking up new ways to snow to replace it in this warmer climate base state”. 

Yeah they look close. I just think there are probably enough subtleties than cant be detected by comparing past h5 composites to a current projected mean. I would have to be convinced that the current Pacific state is not more hostile than say back in Feb 2010, despite the similar h5 looks.

As I said in a discussion we had the other day, I am willing to consider the possibility that what used to be our "money looks" for snow events here may not work as well anymore. Maybe a  -EPO becomes the new -AO.