January Mid/Long Range Disco 3: The great recovery or shut the blinds?

[jayyy]

the 06z GEFS has a really interesting pattern evolution, as the strong -AO ends up dislodging the TPV into Canada. there are also hints of a -NAO developing, which would help greatly with this kind of -EPO setup. a decent handful of members have a ridge bridge between the potential -NAO and -EPO, which would be lights out. there's even some split flow with the weak troughing over the SW US

so, even though the GEFS has some initial weak SE ridging as the pattern establishes itself, which often happens, the pattern quickly becomes very cold and pretty damn favorable north of Philly, but it certainly can work for you guys if the boundary pushed far enough S. I like seeing the signals that the TPV will get displaced and elongated, as we'd have no source region issues at all and HPs will pack a bigger punch... antecedent airmasses are more likely to be favorable as well, and there's semi-permanent confluence where the TPV locates itself:

the EPS and GEPS look favorable due to a farther E ridge into the PNA domain. they both manage to keep the SE ridge offshore and the baroclinic zone S. these patterns would provide numerous chances:

 
I do understand the hesitation and even the pessimism given how this winter has gone, believe me. it's been really frustrating. but looking in a vacuum, this has the potential to become a legitimately good pattern with a bit of luck. there is a risk of cutters, but there's a risk in pretty much every pattern outside of Feb 2010. we're likely going to see one around the 22nd or so that establishes the cold airmass, but that's how these types of patterns go
moving forward, I want to see the -NAO trend a bit more cohesive. this has been happening, but this would change the pattern into something decent to good into a potentially great one. I also want to see the +PNA ridge tick east or for the cross polar flow to strengthen via the potential cutoff high N of AK. this would "force" cold air east regardless of the PNA, similar to what the GEFS has
overall, I still want to wait a bit to see which ensemble suite has the correct evolution, but I'm honestly kind of excited to see where this will go. if the boundary is far enough south, which is certainly possible even without -NAO help (which may show up), then these types of patterns can provide events quickly. regardless, there will be tons of cold air on our side of the globe, and it's a thousand times better than what we've been seeing for the last couple weeks

.

[DarkSharkWX]

38 minutes ago, brooklynwx99 said:

the 06z GEFS has a really interesting pattern evolution, as the strong -AO ends up dislodging the TPV into Canada. there are also hints of a -NAO developing, which would help greatly with this kind of -EPO setup. a decent handful of members have a ridge bridge between the potential -NAO and -EPO, which would be lights out. there's even some split flow with the weak troughing over the SW US

Where do you get the first image from?

[brooklynwx99]

6 minutes ago, DarkSharkWX said:

Where do you get the first image from?

it's the PSU E-wall, it's really useful for looking at the GEFS and GEPS indies

http://www.meteo.psu.edu/fxg1/ewallmref.html

[psuhoffman]

4 hours ago, WxUSAF said:

Good news. Pattern change only 9.5 days away!

 

Fine…..

This is the first serious pattern analysis I’ve done in a while, hopefully it’s warranted and there are more of these coming. 
 

First of all I don’t see a can kick YET. EPS at day 10 looks almost identical to previous runs. 

Whatever differences are incredibly minor for day 10 and noise imo. 
 

The eps was always taking longer to initiate a colder thermal regime after the longwave pattern shift but that’s simply because it doesn’t have the same cold bias as the GEFS and so it doesn’t just magically snap cold instantly the way the Gfs likes to do!  The actual pattern change remains the same on the eps.  Doesn’t mean it’s correct or real, we aren’t in the safe zone yet but no signs it’s a head fake as of now so I guess it’s time to take it more seriously and start a deeper look into what it could mean. 
 

This is the 5 day mean day 10-15  

for reference sake I’m posting the best example of a similar pattern that worked out in a big way here Jan 2014

This is not a prediction I just want something to reference for comparison and as a what to look for.  
 

The most prominent  features are a full latitude easterly centered epo ridge with a ridge bridge over the top with a -AO and a WAR.  

The similarities to 2014 are evident but that doesn’t mean similar results.  But this pattern is fairly rare.  It’s not that 2014 was a rare outcome it’s more that 2014 was a rare pattern combo to lock in for a long period.  There aren’t that many good comps one way or the other.  
 

But from the few there are there are several keys to success

1) location and orientation of the epo ridge.  It cannot end up any further west than it is right there.  That’s already living dangerously as it is without more PNA help.  So far the gefs and eps have been slowly heading towards a compromise. That’s ok so far so long as that compromise doesn’t end up any further west with the pac ridge that currently projected.

2) the orientation and depth of the CONUS trough.  We don’t want it too sharp or deep.  That would lead to a cutter quick cold shot and moderation pattern  cold dry warm wet.  We want a more SW to NE oriented trough which is what the eps shows above at the moment.  We need to watch for changes there.  
 

3) The amplitude of the WAR.  In this look some war can actually help keep waves from being squashed IF it’s suppressed some.  We don’t want to see the WAR building up into the 50/50 space.  
 

All 3 of these factors play off each other.  If the pac ridge shifts east then we could survive a little more WAR and or trough amplitude.  If the pac ridge shifted east into a pna ridge then we would actually want a deeper trough.  If the epo ridge shifts west at all we would need more NAO help and a 50/50 (way less WAR) or we would be toast!  It’s a interrelated equation and each factor influences the others.  

Lastly what made 2014 work in this look was that there was a constant wave train along the boundary but almost none amplified.  There was just a constant train of weak progressive waves.  It’s amazing some of them ended up dropping 8-12” in places frankly given the lack of amplitude but that might be a new normal where it takes less to create a respectable qpf event.  But anything amplified would likely cut.  There were only 3 truly amplified waves that winter and 2 did cut.  The other in Feb tried but it initiated really far SE and there was such a cold airmass with snow cover everywhere over the top of it.  It did still flip to rain in the cities though.  But trust me given our total lack of arctic air lately we don’t want to try that game again.  We need the waves to eject in a progressive way and not an amped up cut off system in that pattern.  We won’t know those details until we’re much closer, for now we wait and hope. 

 

[psuhoffman]

One thing I forgot to point out, don’t let temp anomalies fool you.  As long as we get a temp profile back close to normal the storm track is more important.  And that works both ways.  We can have a high of 45-50 but if the airmass is reasonably dry and a system tracks under is it will snow.  On the flip side we can see a 5 day mean (or a day 10 mean) showing cold because behind a wave it gets cold and the boundary pushes to our south but it systems are too amplified and the ridge axis it too far west on the pac side when the next wave comes it will cut west.  So the pattern looks cold but it’s warm when it’s precipitating.  We all know that cycle!  We need to wait for the details we can’t know yet to find out whether this is actually a good look or not. 

[Ralph Wiggum]

SPV getting beaten to a pulp. This is the most extreme look, on the op, just for visual purposes. All ens means have similar albeit somewhat muted given they are means:

[Ralph Wiggum]

^^^ anything to shake it up a little. Still thinking backloaded times are in store. Whether that means 2nd half fun or a week in March is anyone's guess. This Nina is acting differently and I don't think we have seen all the longwave looks it has to offer just yet.

[peribonca]

The surface low pressure on Saturday afternoon is trending closer to the coast. Anyone think we may end up getting some snow showers out of it? Gfs already showing a dusting in the tidewater.

[psuhoffman]

It’s definitely going to snow. Nora gave me this and said it’s the snowman we’re going to build when it snows. 

[psuhoffman]

2 minutes ago, peribonca said:

The surface low pressure on Saturday afternoon is trending closer to the coast. Anyone think we may end up getting some snow showers out of it? Gfs already showing a dusting in the tidewater.

My guess is it ends up exactly what it looked like days ago from the type of system it is, an eastern New England event possibly.  If I was in Boston I would keep an eye on this. Could we get some snow showers sure but that’s a pretty low bar. 

[psuhoffman]

29 minutes ago, Ralph Wiggum said:

^^^ anything to shake it up a little. Still thinking backloaded times are in store. Whether that means 2nd half fun or a week in March is anyone's guess. This Nina is acting differently and I don't think we have seen all the longwave looks it has to offer just yet.

Agree. But considering we’ve had no snow at all, if we just get a coating between now and April it’s a back loaded winter.  

[EastCoast NPZ]

44 minutes ago, psuhoffman said:

It’s definitely going to snow. Nora gave me this and said it’s the snowman we’re going to build when it snows. 

That's precious. 

[psuhoffman]

6z OP GFS was relatively good for showing the details of how such a pattern could work in reality.  It takes several waves to slowly establish a colder profile into our area.  But eventually we get a snow to ice event and are set up for possibly another frozen event right after the run ends.  But the key to that frozen event day 14 was the wave spacing.  Any more space between waves and that would have been rain also.  But overall a constant wave train like that and it would be unlikely we miss out on EVERYTHING, if we are looking at an extended period in such a pattern.  Todays 12z op was a positive IMO and showed what the details COULD look like.  Not that we want to put much stock in those details but its interesting when an OP does actually match up in general with the pattern the ensembles are showing to get an idea what the details could be in such a look.  

 

[Ralph Wiggum]

54 minutes ago, psuhoffman said:

It’s definitely going to snow. Nora gave me this and said it’s the snowman we’re going to build when it snows. 

Meanwhile my 11 daughter says if it doesn't snow she's taking her scout knife to both of our professional snow tubes. We need snow, really, we do.

[WxUSAF]

8 minutes ago, psuhoffman said:

12z OP GFS is a relatively good for showing the details of how such a pattern could work in reality.  It takes several waves to slowly establish a colder profile into our area.  But eventually we get a snow to ice event and are set up for possibly another frozen event right after the run ends.  But the key to that frozen event day 14 was the wave spacing.  Any more space between waves and that would have been rain also.  But overall a constant wave train like that and it would be unlikely we miss out on EVERYTHING, if we are looking at an extended period in such a pattern.  Todays 12z op was a positive IMO and showed what the details COULD look like.  Not that we want to put much stock in those details but its interesting when an OP does actually match up in general with the pattern the ensembles are showing to get an idea what the details could be in such a look.  

 

I think you’re looking at 6z, but the point is still valid. An active pattern gives us that many more rolls of the dice. There just probably still be more cutters than people want… I think we go from “guaranteed shutout” to “non-zero chance” after the 20th, then chances hopefully get a little better with each subsequent wave.

[brooklynwx99]

3 minutes ago, WxUSAF said:

I think you’re looking at 6z, but the point is still valid. An active pattern gives us that many more rolls of the dice. There just probably still be more cutters than people want… I think we go from “guaranteed shutout” to “non-zero chance” after the 20th, then chances hopefully get a little better with each subsequent wave.

the 12z GFS OP drops the AO to like -7, the NAO to like -5, and the EPO to like -3 and would deliver a sick overrunning pattern. i'll take it

[brooklynwx99]

it's also very important to note that when dealing with a -EPO pattern that features lots of low level cold, heights can be very misleading

using the 12z GFS OP as an example, there's a huge mid level ridge centered over the NE US, absolute torch, right?

nope! not even close. there's a ton of low level cold air in SE Canada with highs in the teens and 20s in New England. a WSW level thump then ensues

keep this in mind when people freak out about weak SE ridges or WARs in the extended on the means. it tells you absolutely nothing about the low levels. the heights are only high because it's torching at like 500-700mb when it's insignificant to precip type

[WinterWxLuvr]

We should have left “shit the blinds” as the title 

[psuhoffman]

8 minutes ago, WxUSAF said:

I think you’re looking at 6z, but the point is still valid. An active pattern gives us that many more rolls of the dice. There just probably still be more cutters than people want… I think we go from “guaranteed shutout” to “non-zero chance” after the 20th, then chances hopefully get a little better with each subsequent wave.

Yea it was the 6z for some reason.  Ill edit my post.  12z actually shows how the pattern COULD fail... everything is too amplified and keeps cutting west and never pulling the boundary far enough east.  But this look at the end is just infuriating. 

HOW is the SE ridge bullying this longwave pattern????  LOOK AT THAT.  TPV trapped south of Hudson bay, huge 50/50 low, extremely -NAO/AO, HUGE EPO ridge.  And a ridge to kingdom come up the east coast! 

 

Yea I see the STJ wave in southern CA and before someone yells "but the PNA" yea BUT the EPO AO NAO 50/50!  There was a huge negative exactly there while we were snowing again and again in 2010!   Like I've said there is an "equation" to all this...and we shouldnt need EVERY SINGLE FACTOR to be totally perfect.  If we do we are FOOKED.  Each thing is an independent variable and if we need 7 or 8 to all line up at some point you reach a point where the math is almost impossible.  This look is going in my notes which are becoming a War and Peace length novel at this point.  

[psuhoffman]

9 minutes ago, brooklynwx99 said:

it's also very important to note that when dealing with a -EPO pattern that features lots of low level cold, heights can be very misleading

using the 12z GFS OP as an example, there's a huge mid level ridge centered over the NE US, absolute torch, right?

nope! not even close. there's a ton of low level cold air in SE Canada with highs in the teens and 20s in New England. a WSW level thump then ensues

keep this in mind when people freak out about weak SE ridges or WARs in the extended on the means. it tells you absolutely nothing about the low levels. the heights are only high because it's torching at like 500-700mb when it's insignificant to precip type

Dunno...that's close for you..but awful for us.  Unless what you are doing is "editing" the run to what you think would happen and that's fine but its also not what it actually shows.  That would be a decent pattern from NYC northward but just rain down here.  WAY too much ridging.  I agree that upper level look SHOULD be a good pattern...but the model is saying it won't be.  Normally...had I not lived through the last 7 years I would say its BS and it will be colder...but I have experienced the last 7 years and time again we have been warmer than I thought we should be given historical precedence in a similar pattern.  So I have stopped doubting when I see what I would think is a "ridiculous warm" outcome from a pattern.  

[TSG]

24 minutes ago, Ralph Wiggum said:

Meanwhile my 11 daughter says if it doesn't snow she's taking her scout knife to both of our professional snow tubes. We need snow, really, we do.

Clearly some strong snow weenie genes you've passed on. You should be proud!

[brooklynwx99]

8 minutes ago, psuhoffman said:

Yea it was the 6z for some reason.  Ill edit my post.  12z actually shows how the pattern COULD fail... everything is too amplified and keeps cutting west and never pulling the boundary far enough east.  But this look at the end is just infuriating. 

HOW is the SE ridge bullying this longwave pattern????  LOOK AT THAT.  TPV trapped south of Hudson bay, huge 50/50 low, extremely -NAO/AO, HUGE EPO ridge.  And a ridge to kingdom come up the east coast! 

 

Yea I see the STJ wave in southern CA and before someone yells "but the PNA" yea BUT the EPO AO NAO 50/50!  There was a huge negative exactly there while we were snowing again and again in 2010!   Like I've said there is an "equation" to all this...and we shouldnt need EVERY SINGLE FACTOR to be totally perfect.  If we do we are FOOKED.  Each thing is an independent variable and if we need 7 or 8 to all line up at some point you reach a point where the math is almost impossible.  This look is going in my notes which are becoming a War and Peace length novel at this point.  

that pattern would probably deliver a huge overrunning event soon, though. tons of cold, and the low off the coast drags the boundary down, energy in S CA ejects, and bang

I wouldn't get too stressed about this run. that ULL in Baja will always lead to a SE ridge, btw. it's like a -4 to -5 sigma anomaly shoving tropical air into the E US, would've popped a ridge here in like 1890. not going to happen like that either way, not really worried about it

[psuhoffman]

2 minutes ago, brooklynwx99 said:

that pattern would probably deliver a huge overrunning event soon, though. tons of cold, and the low off the coast drags the boundary down, energy in S CA ejects, and bang

maybe, probably, but we would have to endure at least one more rainstorm before that likely as the next wave is already amplifying and the boundary is to our NW.  After that maybe we're in business but my point is at that moment its still disturbing when I see a near record -AO/NAO/EPO combo and the SE ridge is still bullying the pattern.  That is a BIG PROBLEM if you are south of 40.  

[brooklynwx99]

2 minutes ago, psuhoffman said:

maybe, probably, but we would have to endure at least one more rainstorm before that likely as the next wave is already amplifying and the boundary is to our NW.  After that maybe we're in business but my point is at that moment its still disturbing when I see a near record -AO/NAO/EPO combo and the SE ridge is still bullying the pattern.  That is a BIG PROBLEM if you are south of 40.  

it's due to a transient feature that's causing it, though. I wouldn't expect that to happen, and once that ejects, you can get a huge storm. and if it shears, you probably get record cold. that pattern would certainly make the entire CONUS cold, it's just the GFS going off the rails a bit. highly doubt that happens

this kind of stuff happens the other way, too. I've seen anomalous 50/50 ULLs keep us at like -10 to -15 at 850 while the rest of the US is a blowtorch

[Maestrobjwa]

15 minutes ago, psuhoffman said:

maybe, probably, but we would have to endure at least one more rainstorm before that likely as the next wave is already amplifying and the boundary is to our NW.  After that maybe we're in business but my point is at that moment its still disturbing when I see a near record -AO/NAO/EPO combo and the SE ridge is still bullying the pattern.  That is a BIG PROBLEM if you are south of 40.  

Maybe we should save the freakout for if it actually happens? Lol I mean I know it's not impossible, the last 7 years, etc but...we ain't there yet, man. I wouldn't even let my brain go there unless we get closer and it starts getting support.

Question: Is it overly simplistic to say a SE ridge is caused by a warm Atlantic? Not sure I understand exactly what influences it.

[Heisy]

Difference between GEFS & GEPS pretty large @ Day 10-11


.

[thunderbolt]

3 minutes ago, Heisy said:

Difference between GEFS & GEPS pretty large @ Day 10-11


.

In what way

[WxUSAF]

4 minutes ago, Heisy said:

Difference between GEFS & GEPS pretty large @ Day 10-11


.

Haven’t seen the GEPS, but hopefully it has that western ridge more onshore. GEFS keeps wobbling it west which will frustrate us.

[psuhoffman]

12 minutes ago, brooklynwx99 said:

it's due to a transient feature that's causing it, though. I wouldn't expect that to happen, and once that ejects, you can get a huge storm. and if it shears, you probably get record cold. that pattern would certainly make the entire CONUS cold, it's just the GFS going off the rails a bit. highly doubt that happens

this kind of stuff happens the other way, too. I've seen anomalous 50/50 ULLs keep us at like -10 to -15 at 850 while the rest of the US is a blowtorch

Not recently. Seems the last 7 years the “weird” only goes one way. But on a longer timescale you’re correct. 

[Ji]

looks like we never got to Phase 8

http://www.bom.gov.au/climate/mjo/