January Long Range Disco Thread

[CAPE]

Just now, WinterWxLuvr said:

LOL that’s one of the best runs we’ve had for the gfs and the first thing said is what’s wrong with it. Time for me to do something else.

That's at least 2 runs in a row.

[cbmclean]

3 minutes ago, CAPE said:

We shouldn't be "afraid" to mention/discuss unfavorable pattern elements that show up on an ens run in a LR thread. 

Maybe we need fainting couches for those who are perpetually on the edge of panic in here. 

 

5 minutes ago, CAPE said:

We shouldn't be "afraid" to mention/discuss unfavorable pattern elements that show up on an ens run in a LR thread. 

Maybe we need fainting couches for those who are perpetually on the edge of panic in here. 

I admit to being a fainter, but I try to keep my spells off of the board.

That being said, I am only able to devote a tiny percentage of the time to this hobby that I would like right now so I depend on this board for pretty much all my LR information.  I'm actually going to try to make myself a little chart to encapsulate a subjective opinion the status of how good or bad the pattern looks on the two primary ensembles (GEFS, EPS).  To keep it apples-to-apples I am only going to ignore the 06Z and 18Z GEFS, and just consider at the 00Z and 12Z runs. 

So my plan is to fill in this chart with values from 1 - 10, with 1 being last January and 10 being the best pattern you can imagine.

I accept any and all suggestions for numbers

                        00Z GEFS        00Z EPS

Day1 - 5                3                      3

Day 6 - 10             5                      5

Day 11-15            7                      1

 

[cbmclean]

12 minutes ago, WinterWxLuvr said:

You saying the EPO has no correlation to cold? Cold has a correlation to snow.

But it also has a correlation to dryness.  No moisture, no snow.

[psuhoffman]

2 hours ago, CAPE said:

Yeah I get the great snow analogs and all with the big ass NE Pac trough, but that works better in a Nino, and the Pac jet has been on steroids in recent years.

True but that enhanced pac jet (which isn’t really a Nina issue it’s a byproduct of the increased thermal gradient in the pac due to the warning base state supercharging the jet and it’s been there regardless of enso for a long time now) has put us in a double bind. You’re right that with a strong pac jet the trough in the N PAC directs that pac firehouse up into Canada and destroys our cold source regions. But if that N PAC trough relaxes the forehose usually ends up directed right into the lower 48 and that leads to either a totally zonal puke pattern or if there is a trough out west a super ridge in the east and we are 65 degrees.  That enhanced jet also makes it very unlikely to sustain the kind of crazy concurrence of variables needed to offset it. Yes if we could get a perfectly placed stable full latitude east based positively tilted EPO ridge that would mitigate the pac. But the enhanced jet makes that even more unlikely then it would be normally (and it’s pretty rare to begin with). That fast jet has destructively interfered with every attempt at high latitude ridging and PV disruption for years. Imo the fact we had a N PAC trough (imo aided by the very off warm over cold SST pattern) muted the issue and it’s not a coincidence that coincided with the first stable long lasting winter high latitude blocking regime we’ve had in forever. 
 

So the double bind is this...with that N PAC vortex you direct an enhanced pac jet into Canada and wrench the thermal profile of our source region. But if you lose that the pac jet goes zonal and blasts pac puke into the lower 48 and the fast zonal flow in the pac destructively interferes with any blocking attempts so we get a +NAO and ridge in the east!  I don’t see a “win” there but the lesser of the evils imo is the N PAC vortex. Maybe Im wrong but given enough chances I feel the odds were better if eventually getting a couple of the perfect track storms to be “just” cold enough v battling with the imo more destructive effects of the pac jet in a more zonal flow. But I could be wrong. It’s frustrating. We really need that pac jet to relax but it hasn’t for a long time and that is regardless of enso. 
 

ETA: this is a bigger picture long timescale point. I think this year we might get a window where we get that rare “just right” Goldilocks in between balance. But longer term we’re going to be really frustrated if that’s what it takes to ever snow. 

[Dabuckeyes]

Great run for GFS and Para. The window PSU has been talking about is now showing up with a good looking storm. That’s step 1. Temp and precip type is a long ways away. 

[cbmclean]

4 minutes ago, psuhoffman said:

increased thermal gradient in the pac due to the warning base state

I am curious as to why there is an increased thermal gradient.  My understanding is that high latitudes are warming faster than the tropics so I would expect that to lead to a reduced thermal gradient.

[cbmclean]

6 minutes ago, psuhoffman said:

 I don’t see a “win” there but the lesser of the evils imo is the N PAC vortex.

The NPAC vortex is also probably an even lesser of the two evils when it is not preceded by a month long +AO torch that causes Canada to be warm to begin with.  

[cbmclean]

An ignorant question I know, but when actually are the approximate times that the 00Z/12Z ensembles tend to become available?

[psuhoffman]

@WinterWxLuvr @CAPE

I added some ETA to my last post before even reading these posts because of “this” issue.  I agree with you Cape that multiple threads would be better partly for this reason. There are discreet threat level thoughts, long range longwave pattern level, and then even super long term decadal level patterns thoughts. And they all get mixed in here. Sometimes I am making an observation about something pertaining to decadal level pattern and people take it as pertaining to a current threat.  I can multitask in this one thread and it doesn’t bother me that much but some seem to confuse these different trains of thought and conversation and it gets frustrating. 

[cbmclean]

Just saw a post in the banter thread from leesburg 04 that the 12Z  GEFS caved to the EPS.  Is this true? 

[WxUSAF]

I don’t think a “pattern” vs “storm” thread would work well. But maybe a “inside 7 days” vs “beyond 7 days” could work?

[psuhoffman]

@CAPE one last point wrt the pac issue. To simplify the relationship with the N PAC vortex...the warmer base state of the PAC has enhanced the jet and that in a nutshell means there is going to be this big firehose of warmth directed somewhere. And unfortunately we are downwind of it. But where would we rather it directed?  Across the mid latitudes (directly at us) and enhancing a screaming zonal flow around the mid latitude northern hemisphere that also enhances the PV to its north!  We have seen what that looks like plenty recently right?  Big ring of red around with a blue ball of death over the pole. Good luck!  Or do we want a vortex in the north Pac to take the fire hose and direct it up into the high latitudes and at least disrupt the PV and create chaos!  Either way the whole base state is warm. But one seems to give us more of a fighting chance. Again this is just a 10,000 foot view observation. 

[psuhoffman]

4 minutes ago, WxUSAF said:

I don’t think a “pattern” vs “storm” thread would work well. But maybe a “inside 7 days” vs “beyond 7 days” could work?

I agree with that. We shouldn’t be discussing details with a storm more then 7 days out anyways. I was thinking more for stuff day 3-6. We used to have threads before we decided that was bad luck. 

[CAPE]

1 minute ago, psuhoffman said:

I agree with that. We shouldn’t be discussing details with a storm more then 7 days out anyways. I was thinking more for stuff day 3-6. We used to have threads before we decided that was bad luck. 

Maybe just have a LR discussion thread(this one) and then make another one for identifying/discussing potential discrete threats inside 6 days. When we get inside 3 with a legit threat we can make a specific storm thread and jinx it.

[SnowDreamer]

18 minutes ago, cbmclean said:

An ignorant question I know, but when actually are the approximate times that the 00Z/12Z ensembles tend to become available?

Depends a lot on the forecast range you're waiting for, but WxBell lists the following: 

GEFS: 10:30-1:20

EPS: 1:45-2:50

Since we tend to favor ensembles in the LR, my personal rule of thumb is to wait an hour until after the OP starts. 

[psuhoffman]

12 minutes ago, cbmclean said:

Just saw a post in the banter thread from leesburg 04 that the 12Z  GEFS caved to the EPS.  Is this true? 

My source is only updated to day 13 so I can’t say what happens at the end but day 9-13 looks much better on the GEFS still with a more elongated trough that extends into the Atlantic vs dumping it all into the west right after the initial dump around the 15th. 
0z EPS

12z GEFS same time 

[MocoMike]

10 minutes ago, cbmclean said:

Just saw a post in the banter thread from leesburg 04 that the 12Z  GEFS caved to the EPS.  Is this true? 

Hmm...from what I can tell, it did not. It actually looks a little better in the Pacific  than 0z, no? 

0z v 12z

 

[nw baltimore wx]

15 minutes ago, cbmclean said:

Just saw a post in the banter thread from leesburg 04 that the 12Z  GEFS caved to the EPS.  Is this true? 

Yes. And worse, IND about to cave to BUF.

[psuhoffman]

1 hour ago, cbmclean said:

I am curious as to why there is an increased thermal gradient.  My understanding is that high latitudes are warming faster than the tropics so I would expect that to lead to a reduced thermal gradient.

It’s more about potential energy. An increase in water temps from 80 to 85 will add a lot more heat/energy then an increase from 35 to 45 in the higher latitudes. Same with the air. Warning in the tropics will add a lot more heat then the warning in the Arctic does. 

[CAPE]

29 minutes ago, WxUSAF said:

I don’t think a “pattern” vs “storm” thread would work well. But maybe a “inside 7 days” vs “beyond 7 days” could work?

I am fine with everything in one thread, but others seem to get annoyed with some of the more esoteric posts(SSWE) and discussion/analysis of LR/extended tools.' so it was a  suggestion to alleviate that 'issue'. I get that it may quickly turn into a mess if people are not cognizant of what belongs where.

Your call my friend.

 

[psuhoffman]

Wrt the GEFS v EPS... hope this illustrates the difference better 

features 1-4 are the same on both. But 5/6 are there on the GEFS and not EPS. GEPS is kind of in between. Feature 5 there is crucial. That extension of the pac ridge into the high latitudes taps true polar cold and directs it down into the Conus. That creates a broader colder trough in the US that presses the thermal boundary into the east allowing storms to amplify further east under the block which leads to feature 6. The SE ridge (2) can be mitigated by 5/1/6 in that look. It’s a critical mass thing. Get a cold enough profile to set off the chain reaction we want and that all starts with that ridge up near AK. The strong 50/50 signature along with a cold enough airmass will stop storms from cutting end the SE ridge could even end up helping us to stop suppression. But if that ridge near AK fails and not enough cold gets into the pattern the trough won’t press, it will pull back fully into the west and storms will cut and then wash out when they hit the blocking ridge.  The NAO block will be rendered useless. ATT I favor the GEFS look. The high latitudes have favored ridging this year and the pacific progression favors that. But I’m not ruling out the EPS. I’d like to see it flip back.  Hopefully I’m not driving everyone nuts with this stuff. Just trying to explain what could make the pattern go one way or the other. 

[Ralph Wiggum]

1 hour ago, CAPE said:

That's at least 2 runs in a row.

Signal for that period 18th-23rd getting stronger across the board with each run.

[frd]

2 minutes ago, Ralph Wiggum said:

Signal for that period 18th-23rd getting stronger across the board with each run.

Optimism 

[frd]

10 minutes ago, CAPE said:

I am fine with everything in one thread, but others seem to get annoyed with some of the more esoteric posts(SSWE) and discussion/analysis of LR/extended tools.' so it was a  suggestion to alleviate that 'issue'. I get that it may quickly turn into a mess if people are not cognizant of what belongs where.

Your call my friend.

 

I am with you CAPE but I feel this is one of the best overall winter long range threads on the web 

[Ralph Wiggum]

Just now, frd said:

Cautious Optimism 

Fyp

[cbmclean]

9 minutes ago, psuhoffman said:

Hopefully I’m not driving everyone nuts with this stuff.

Honest question, who could you possibly be driving nuts with this?  If one is not interested in discussions like that, why would they be here?  I'm honestly perplexed.

[frd]

@poolz1   

 

 

[Scraff]

3 minutes ago, frd said:

I am with you CAPE but I feel this is one of the best overall winter long range threads on the web 

I’m a much bigger fan of the old Accuweather forums....said nobody ever!!

[frd]

 

 

@psuhoffman

This has to be a positive in my book. 

 

 

[psuhoffman]

1 hour ago, WinterWxLuvr said:

You saying the EPO has no correlation to cold? Cold has a correlation to snow.

It has some correlation to cold. It definitely correlates to cold in the US but that correlation becomes weaker the further east of the Miss you get.  Almost every arctic outbreak does coincide with a -EPO because it produces cross polar flow. But most of our Arctic outbreaks don’t feature significant snowstorms.  Details matter but in general an EPO ridge will focus the cold too far west of us and unless there are mitigating coinciding factors like a -NAO or displaced TPV in SE Canada the storm track will be to our west. The gradient often isn’t that far away so the cold can get in behind each wave but with the longwave trough axis so far west anything that amplifies will usually cut. You get a little NW of us or into New England and that can be a great pattern with storms riding the gradient. But we usually end up SE of the track here. Only in very rare cases like 2014 and 2015 does it work out and they took some rare combinations of a displaced TPV and an extremely positively tilted poleward EPO ridge. Looking at all our warning snowfalls the EPO was almost evenly split. The EPO alone just doesn’t correlate much to our snowfall. I will end with this since some have pointed this out...if we need true arctic air going forward to get snow then the EPO probably will become more correlated to snow. But that would be a VERY BAD thing!