Winter 2014-2015 Pattern Discussion Thread I

[burgertime]

Triple phaser ftw!  

 

There is one every year! By the way when does super thread II start? 

[packbacker]

While last nights runs (outside of the 00z GFS) didn't look great in the LR one thing I'm liking is that yesterday every model had 850 anomalies seasonal in the east for the 6-10 day range (except the Euro) and then well below in the 10-15 day range. I don't buy the Euro wrapped up solution as it has it. I get all the energy floating around I just don't think it all phases to get a super bomb. I'm betting that southern piece doesn't link up with that northern jet....or the southern energy cuts and and phases with one piece of energy for a lakes storm....just don't think it all comes together to make a bomb for the OV.

What was wrong with the GEFS? They looked great to me starting day 9 on. CMC-ENS agree.

[burgertime]

What was wrong with the GEFS? They looked great to me starting day 9 on. CMC-ENS agree.

 

Oh GEFS looks fine....Sorry I was talking about the CMC and Euro at around 240 hours last night. It looks like the cold is starting but GEFS/CMC ENS looked much better at that range. 

[buckeyefan1]

There is one every year! By the way when does super thread II start? 

Whenever you start it     

[Cold Rain]

The Euro OP at 192 is a great example of how you can have a nice west-based -NAO and still get screwed.  The trough out west will ensure a healthy ridge over the east and should promote some nice west tracking storms.

 

 

The models are becoming consistent about developing a west-based -NAO.  That is good.  It's still up in the air how long it lasts.  But all the ops dig a trough out west around D10, to some degree or another.  All of them.  It sucks to go from a garbage pattern to a crap pattern, but I guess we will have to endure that to get to something better.  Hopefully, it won't last too long.

[packbacker]

The Euro OP at 192 is a great example of how you can have a nice west-based -NAO and still get screwed.  The trough out west will ensure a healthy ridge over the east and should promote some nice west tracking storms.

 

f192.gif

 

The models are becoming consistent about developing a west-based -NAO.  That is good.  It's still up in the air how long it lasts.  But all the ops dig a trough out west around D10, to some degree or another.  All of them.  It sucks to go from a garbage pattern to a crap pattern, but I guess we will have to endure that to get to something better.  Hopefully, it won't last too long.

 

Just playing around with analogs, looked at ++PDO years (+1 or higher) that had a +PDO in the fall and you get this...

[Cold Rain]

^ Wonder when that sets in?

[packbacker]

^ Wonder when that sets in?

 

Jan 1st 

[Cold Rain]

Jan 1st 

 

Haha!  I really can see how the Ops will struggle because A) A pattern transition is in the making and B ) There is a lot of energy in the flow, and the delicate timing and interaction of these shortwaves have downstream effects in the models' rendering of the pattern.

 

Therefore, the way I look at the operational models is not focusing on individual storms beyond, say, 3 days.  I look at them more in the 5-10 day period around how they agree with each other and with the previous runs of themselves and how they agree with their ensembles regarding the overall pattern.

 

Like today, I'd give the -NAO a good chance of verifying in the 8-10 day period or so, for the above reasons mentioned.  I'd also give the trough out west a good chance of verifying.  How long either feature lasts is up in the air.  There hasn't been a lot of clarity around that yet.  The ensembles continue to show a ridge west and trough east, which is good.  At some point, and I don't know when, the Operational models HAVE to come around to that same depiction in the 5-10 day range.  And they HAVE to show it consistently (not every other run or two, like we've seen) in order to take seriously that a change to a cold pattern is imminent.

 

Until they do that, reports of favorable patterns are premature and based on hoping the analogs and ensembles turn out to be correct.  Don't get me wrong...they *should*, but any model forecast beyond 10 days, as we all know, has low skill...even if all the ensembles are in agreement (of course the skill should be higher if they are all in agreement, but beyond 10 days, skill is still low).

 

So, we must continue to wait and hope and see whether or not we eventually get what we want.  I think we will, but waiting for it sure is not an easy thing.

[Southern Track]

My morning indeces update.  PNA looks to stay at least neutral to slightly positive, while we see agreement on a -AO/NAO.

 

[Cold Rain]

From DT in the mid Atlantic forum:

 

[griteater]

Euro ens originally kept the SE in some weak ridging in the long range.  The past few days it has been flipping back and forth between weak ridging and no ridging.  Overnight run had the weak ridging again.  GFS Ens has been steady with a below normal temp pattern developing.

[deltadog03]

Through 18z TUE HR102, the gfs is further south with the Upper closed low.  The energy is more bundled as well so far vs the 00z run.  Lets see where this goes.

[Jon]

NC DT Speculation. Not bad. I don't know if that "FLAT" SE ridge will stay or not, it keeps showing up and disappearing or not being as strong on each Euro ENS run. I agree with him on everything else though and the PV location as seen from some H5 maps I've posted, it's going to be there. Other solution is we just get a ton of cold and we could still get a pattern that works, it just may not be what he pointed out considering its extremely long range. The point remains the pattern is changing.

[deltadog03]

Trof a smidge slower, but more consolidated and sharper with the trof.  Looks good, but windy...LOL

[franklin NCwx]

NC DT Speculation. Not bad. I don't know if that "FLAT" SE ridge will stay or not, it keeps showing up and disappearing or not being as strong on each Euro ENS run. I agree with him on everything else though and the PV location as seen from some H5 maps I've posted, it's going to be there. Other solution is we just get a ton of cold and we could still get a pattern that works, it just may not be what he pointed out considering its extremely long range. The point remains the pattern is changing.

it will be very cold in the low levels. That's some true Siberian air.

[Brick Tamland]

WRAL's Greg Fishel posted this on Facebook this morning:

 

The ensembles had the right idea, sorta. Ten days ago, I was impressed with the fact that so many ensemble members were amplifying the upper air flow pattern 2 weeks in advance. Well, that amplification is going to occur, but it may be very short-lived. Why? It appears many models are having a fit with a strong jet stream across the Pacific Ocean. As long as disturbances continue to ram into the west coast of the U.S., it will be next to impossible to get wintry weather into the SE United States.

[Jon]

it will be very cold in the low levels. That's some true Siberian air.

Yeah I think he may be jumping ahead and trying to point out a storm track and that's nice and everyhting but as we get closer that can change then he'll make a new map, etc. I like to just find the cold first, know we're getting that, then as we get closer look at the STJ and what not.

 

I think I mentioned to someone I saw an image of how important each index or factor was this winter. I found it. Couresy of Rob Guariano (met) he owns liveweatherblogs.com but he's been a TV met in the past...I *think* he made this image as it's in his blog post from 6 months ago lol. Not sure the science or evidence behind the percentages though, figure he did some research on it. Who knows, just thought I'd follow up.

 

[burgertime]

Don't like how the storm wraps up on the 12z but you can see the pattern change coming at 204 - 216. Good sign. 

[Batman]

My morning indeces update.  PNA looks to stay at least neutral to slightly positive, while we see agreement on a -AO/NAO.

 

It would seem to me that the forecast of a slightly -NAO and slightly +PNA (if true) would make it difficult for a trough to settle in the SW for any amount of time. Maybe the trough is broad based? Maybe it is transient? Maybe it is just one of the options on the table with the pattern changing and so much energy in the NH? Somebody with more skill and knowledge please weigh in and share your thoughts. Just seems to me that if the NAO and PNA forecasts are correct, the SW trough would be very difficult to achieve.

[burgertime]

12z GFS looks kind of ugly in the LR. Cold in the west. It eventually starts moving east. 

[metwannabe]

12z GFS looks kind of ugly in the LR. Cold in the west. It eventually starts moving east.

Ensembles don't support the west dump. The west dump could end up being right but . I actually liked the 12z run. It's very very active the 28th-2nd

[tnweathernut]

Holy - NAO batman.  That really begins to build around hour 144.  The western ridging also really builds a couple of days after, so much to that is shows eventually linking with the higher heights over Greenland, putting a lot of colder air in North America.  That kind of look, if right, would surely yield opportunity.

[BullCityWx]

12z GFS looks kind of ugly in the LR. Cold in the west. It eventually starts moving east.

That's a really bad look. Cold that seeps east will always moderate.

[BullCityWx]

Coldest temp on that run in the next 16 days for CLT is 31.

[tnweathernut]

500 moves toward a very good look, see hour 228..............and a bunch of time frames before and after it too for that matter.

 

 

Using this as a plug to buy the AmWx model center too, if you don't already have access to it.  A TON of models and maps to look through. Highly recommend!

[mackerel_sky]

Coldest temp on that run in the next 16 days for CLT is 31.

Luckily, it's just 1 op run! These models really are having a hard time in the med- long range. I think things will shake out and get a feel for the pattern, until after the Christhmas Eve storm, and how strong it is.

[griteater]

It would seem to me that the forecast of a slightly -NAO and slightly +PNA (if true) would make it difficult for a trough to settle in the SW for any amount of time. Maybe the trough is broad based? Maybe it is transient? Maybe it is just one of the options on the table with the pattern changing and so much energy in the NH? Somebody with more skill and knowledge please weigh in and share your thoughts. Just seems to me that if the NAO and PNA forecasts are correct, the SW trough would be very difficult to achieve.

 

Keep in mind that those indicies are purely from the GFS Ensemble which has been consistent in showing a cooler / colder pattern developing.  The Euro Ens from last night, on the other hand, had the PNA going negative in the final week of Dec with less of a cold air press into the southeast.

[Southern Track]

500 moves toward a very good look, see hour 228..............and a bunch of time frames before and after it too for that matter.

 

 

Using this as a plug to buy the AmWx model center too, if you don't already have access to it.  A TON of models and maps to look through. Highly recommend!

To my untrained eye, that would be a west based -NAO correct?

[CandymanColumbusGA]

Heck... I'll be happy when we finally have cold air on our side of the Globe. The rest will come with patience.

Here's the link: http://models.weatherbell.com/climate/ncep_cfsr_t2m_anom.png