February Medium/Long Range Discussion Thread

[gymengineer]

1 minute ago, psuhoffman said:

It's the only reason I still have hope those two factors are real influences and they both have strong signals right now. That gives me some pause before just saying it's over.  But it's getting late. This next reshuffle is our last chance probably.  So we have to get it right. 

People have been saying how the models Lucy us all winter. And I think I sometimes write a paragraph of analysis of what's going on behind the scenes and some simple think "yea but it didn't snow" and while I want snow too I also like trying to learn and figure this out. 

Lucy pulls the football at the *last moment* each time in the Charlie Brown stories. That applies to situations like 12/26/10 or 2/21/11 or 3/6/13 or 12/10/13--- the ones where we/parts of the area are actually under a Winter Storm Warning and the storm busts horribly. That's a crap-load of events as it is. No need to expand it to mean any moment that stresses out any model watchers. 

All the pictures or references of Lucy no matter how many days out we are-- that's just kind of lazy. I agree that a 10-12 day window of interest going wrong at day 7 is not an indictment of the state of models. That's not Lucy pulling the football at all. 

[winterymix]

7 hours ago, psuhoffman said:

This is our biggest problem and best hope all in one. The suddenly shift to crap in the medium range happened right as the mjo trended towards more amplitude into warm phases. But it's also spiking into cold by day 11. 

This is what I've been waiting for all winter.   We get into phase 7 around February 09 and I betcha were are going

to get some accumulating snow soon after.

[NorthArlington101]

NAM is more north and more amped with the Fri-Sat deal, but there is a long way to go. 

Doubt I'll bother to stay up for it, but the GEFS overnight should be telling on if we (which might just be me and WinterWxLuv) need to give up on it or not. 

[Wonderdog]

12 minutes ago, gymengineer said:

Lucy pulls the football at the *last moment* each time in the Charlie Brown stories. That applies to situations like 12/26/10 or 2/21/11 or 3/6/13 or 12/10/13--- the ones where we/parts of the area are actually under a Winter Storm Warning and the storm busts horribly. That's a crap-load of events as it is. No need to expand it to mean any moment that stresses out any model watchers. 

All the pictures or references of Lucy no matter how many days out we are-- that's just kind of lazy. I agree that a 10-12 day window of interest going wrong at day 7 is not an indictment of the state of models. That's not Lucy pulling the football at all. 

I agree that it isn't Lucy pulling the football at the last minute wrt to the models changing their tune at day 7 from Day 10-12. But what that tells me is that in the progressive pattern we are in this winter, it seems that the models can't seem to get it right (or in some cases close to right) at long leads. If you know and accept that going in, it makes the disappointment more palatable. My question is if the MJO gets into a more favorable location, would that necessarily slow the progression of the systems down across the country?

[psuhoffman]

28 minutes ago, kurtstack said:

To be honest we are probably trying to understand something that we may not possibly be able to comprehend. We use models that digest millions of data points and progress all of those pieces of data forward in time based on complex multi-variable thermodynamic and fluid dynamic equations over a spherical three dimesnional surface. You say there must be a driver causing the models to predict a -ao errantly, but perhaps there are thousands of drivers across the globe all influencing it to some extent. So i dont think it gives it justice to point to one index as the driver of any given errors in the model output but rather believe it is a complex combination of multiple variables across the globe that are affecting the forecast indices for better or worse.


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I acknowledge just what you said in my next post after the one you quoted. That it could be a "complex combination of factors in a delegate balance the models have no hope of calculating correct".  But there are some logical factors that argue it could be one or two overlaying influences. The thousand small things theory would easily explain one failing but a trend all season over and over would suggest there is something persistent in the base state the models are not giving enough weight. Or vise versa giving it too much. The odds of a lot of small influences lining up randomly to cause the same error again and again is lower. Still possible but it could be one or to things. We may never know. 

But just because we may not be able to figure it out doesn't mean we shouldn't talk about it or try. Without effort and failure there is no progress. 

[kurtstack]

4 minutes ago, psuhoffman said:

I acknowledge just what you said in my next post after the one you quoted. That it could be a "complex combination of factors in a delegate balance the models have no hope of calculating correct".  But there are some logical factors that argue it could be one or two overlaying influences. The thousand small things theory would easily explain one failing but a trend all season over and over would suggest there is something persistent in the base state the models are not giving enough weight. Or vise versa giving it too much. The odds of a lot of small influences lining up randomly to cause the same error again and again is lower. Still possible but it could be one or to things. We may never know. 

But just because we may not be able to figure it out doesn't mean we shouldn't talk about it or try. Without effort and failure there is no progress. 

You know i appreciate the effort and discussion.  I think the mystery is why we love this hobby - and the white gold - I deal with more sinplistic models to simulate how long a tank car with 1/2" thick steel loaded with crude oil and equipped with a pressure relief device will survive being engulfed in a pool fire before rupturing.  Now for some reason we cant seem to verify that forecast either - and when you dig into the root cause of the problems often times you find innacuracies in assumptions made at initiation.  I suspect the weather models are the same and since we dont have infinite amount of data points the models have to make some assumptions at initiation, and we have to tell the conputer what assumptions to make where there are no data points - then a small error on the initial assunptions progresses into larger scale inaccuracies the further out in time we go.  so to get to the root cause of errant ao forecasts we would have to identify where the greatest errors are occuring at initiation and the short range - as they are ultimately leading to the errant ao forecast downstream.   

[psuhoffman]

59 minutes ago, BristowWx said:

I sometimes wonder if JB puts out the same hype-ish forecasts to his core business traders.  It's one thing to tell a bunch of weenies it's going to be cold and snowy and then bust but another to tell those who pay for accuracy because they have skin in the weather (oil and gas futures, retailers etc) the same thing and be wrong.  My guess is no.  Those forecasts are likely his real thoughts and probably far more steeped in the facts. He might be a wishful weenie at heart but business is business and cash rules.Those type clients are not interested in snow and cold because they are winter weather enthusiasts.   Just my 2 cents.

That's an interesting thought. Of course those same clients could see his other forecast and be like "wtf". All it would take is one client going public to cause a lot of embarrassment. It's more likely he issues the same forecast but then edits it and gives more realistic day to day thoughts that are more useful then the "I'm going down with the ship" crap he pulls with the public.  

[BaltimoreWxGuy]

I mean I know we think the Sun system was dead but what a disastrous run from the GFS for Sun lol not even any precip

[kurtstack]

seems to be some improvement up top at 153 hours on the gfs - wont get it done this run but an improvement with confluence showing up.


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[SnowGoose69]

5 minutes ago, BaltimoreWxGuy said:

I mean I know we think the Sun system was dead but what a disastrous run from the GFS for Sun lol not even any precip

The GFS was entirely northern stream that run.  Whenever the GFS is going hard with something out of Canada and the Euro isn't, the GFS is usually correct.  The Euro although it's been stronger with the Sunday system than it was 2-3 days ago it has been entirely southern energy oriented. 

[stormtracker]

10 minutes ago, kurtstack said:

seems to be some improvement up top at 153 hours on the gfs - wont get it done this run but an improvement with confluence showing up.


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Hold the phone..it does seem radically different vs 18z and previous runs with that high showing up.  Hell, at 162, it starts out as snow.*  No, it doesn't get the job done, but it's a marked improvement.  I wonder if it keeps up

*nevermind, looked at the wrong thing.

[BaltimoreWxGuy]

2 minutes ago, SnowGoose69 said:

The GFS was entirely northern stream that run.  Whenever the GFS is going hard with something out of Canada and the Euro isn't, the GFS is usually correct.  The Euro although it's been stronger with the Sunday system than it was 2-3 days ago it has been entirely southern energy oriented. 

Yeah but even the Euro doesnt show much right?

[kurtstack]

The entire run was a strange evolution start to finish. The king will tell us shortly if there is any trend on the 153 hour deal.


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[psuhoffman]

Damn I think that gfs run found every way to miss us with snow possible.  

[psuhoffman]

1 hour ago, stormtracker said:

Hold the phone..it does seem radically different vs 18z and previous runs with that high showing up.  Hell, at 162, it starts out as snow.*  No, it doesn't get the job done, but it's a marked improvement.  I wonder if it keeps up

*nevermind, looked at the wrong thing.

Gefs suddenly spikes the snow mean day 7-9 and there are a few massive hits. Enough there to keep one candle lit for the threat I suppose. 

Back to sleep. Hopefully when I wake up showmethesnow will be working on his post analyzing how the EPS has several big hitters in that time period and it has promise. 

[CAPE]

5 hours ago, psuhoffman said:

Gefs suddenly spikes the snow mean day 7-9 and there are a few massive hits. Enough there to keep one candle lit for the threat I suppose. 

Back to sleep. Hopefully when I wake up showmethesnow will be working on his post analyzing how the EPS has several big hitters in that time period and it has promise. 

Decent spike in the snow mean on EPS between days 8-10. Some big hits in the mix. Looks like there is some signal for a coastal low centered on day 9.

[Wonderdog]

12 minutes ago, C.A.P.E. said:

Decent spike in the snow mean on EPS between days 8-10. Some big hits in the mix. Looks like there is some signal for a coastal low centered on day 9.

What are the things I need to look at for me to come up with the same conclusion that you have to identify signal for a storm?

[PDIII]

7 minutes ago, Wonderdog said:

What are the things I need to look at for me to come up with the same conclusion that you have to identify signal for a storm?

Wonderdog:

I think that this is the stuff they keep secret here ;). .. At any rate, I would stick to looking at the precip maps on Ops.  Although there are features, such the teleconnection indices, upper level patterns, blocking patterns, longer wave stuff.. etc (stuff that I dont understand) that may have a little bit longer lead time on the global models... these are often wrong also 10-15 days out.  

I just check the GFS OP Precip/ SLP... when the 10 day storm sticks around to 6 days... I get excited.  

 

 

[PDIII]

BTW.. there is a trailing wave on the cuttter next week on the 6Z. One week from now.

[CAPE]

21 minutes ago, Wonderdog said:

What are the things I need to look at for me to come up with the same conclusion that you have to identify signal for a storm?

For surface stuff I look at the mean, the 51 individual members, and low locations for a given period. I have been busy with work so I have not been looking at every run, but on the 0z EPS there is something during that window. Not a consensus by any means, and we have been here many times before at long leads.

[CAPE]

1 minute ago, PDIII said:

BTW.. there is a trailing wave on the cuttter next week on the 6Z. One week from now.

Thats the potential storm/period of interest...late next week

[midatlanticweather]

20 minutes ago, Wonderdog said:

What are the things I need to look at for me to come up with the same conclusion that you have to identify signal for a storm?

This is a bit helpful. Knowing patterns will help. You get pretty good descriptions from Psu and chill that help! https://www.google.com/url?sa=t&source=web&rct=j&url=https://www.abington.k12.pa.us/teachers/hurmms/Majorsnowstormchecklist_files/Stormchecklist.ppt&ved=0ahUKEwiyyNDH5O7RAhXJfZAKHfxCAU44ChAWCCIwAw&usg=AFQjCNH8x7HlChuJKTLaB0zYLMyZQMSxCQ

[psuhoffman]

I count 16 EPS members with a fairly significant snow across the area. 4"+. About 8 are massive hits. Then another handful of small shows. 1-3". Then a big cluster of very close misses. And those are split between misses to the NW and SW. Adding all those groups together actually does give a consensus for a second wave to amplify along th coast behind the cutter. And right now looking at just the 8-10 period we're the bullseye. But all that said this is not a way we typically win and especially not from long leads so I'm more skeptical then the numbers would suggest. 

[winterymix]

48 minutes ago, midatlanticweather said:

This is a bit helpful. Knowing patterns will help. You get pretty good descriptions from Psu and chill that help! https://www.google.com/url?sa=t&source=web&rct=j&url=https://www.abington.k12.pa.us/teachers/hurmms/Majorsnowstormchecklist_files/Stormchecklist.ppt&ved=0ahUKEwiyyNDH5O7RAhXJfZAKHfxCAU44ChAWCCIwAw&usg=AFQjCNH8x7HlChuJKTLaB0zYLMyZQMSxCQ

Nice PPT,  thank you.

[CAPE]

28 minutes ago, psuhoffman said:

I count 16 EPS members with a fairly significant snow across the area. 4"+. About 8 are massive hits. Then another handful of small shows. 1-3". Then a big cluster of very close misses. And those are split between misses to the NW and SW. Adding all those groups together actually does give a consensus for a second wave to amplify along th coast behind the cutter. And right now looking at just the 8-10 period we're the bullseye. But all that said this is not a way we typically win and especially not from long leads so I'm more skeptical then the numbers would suggest. 

This is probably the biggest red flag. That type of evolution seems like one of the lower probability ways to get a snow event around here. Hopefully I am wrong, but this specific "threat" will probably fade from the means pretty quickly.

[Scarlet Pimpernel]

1 hour ago, Wonderdog said:

What are the things I need to look at for me to come up with the same conclusion that you have to identify signal for a storm?

I guess others have already described what to look for meteorologically.  I was just going to add that access the Euro model and ensembles would be required too, I assume!  That's kind of the tricky part.  Not sure if you have one of those model packages...I don't (though have been tempted!), and usually look at TT which at least gives you some stuff from the Euro and the EPS mean.

[Scarlet Pimpernel]

43 minutes ago, psuhoffman said:

I count 16 EPS members with a fairly significant snow across the area. 4"+. About 8 are massive hits. Then another handful of small shows. 1-3". Then a big cluster of very close misses. And those are split between misses to the NW and SW. Adding all those groups together actually does give a consensus for a second wave to amplify along th coast behind the cutter. And right now looking at just the 8-10 period we're the bullseye. But all that said this is not a way we typically win and especially not from long leads so I'm more skeptical then the numbers would suggest. 

Yeah, this is always an iffy proposition here, but every now and then we get it to work.  Not saying that it will here, but it raises an eyebrow (somewhat, at least!) if the ensembles are actually showing some consensus on that.  March 5, 2015 is the best (recent) example I can recall where this worked out perfectly for us.  In fact it was hinted at in the models (GFS in particular sticks in my mind) a week out with a form of anafrontal snows.  In the end, we did indeed have a cold front go through before dawn, temperatures fell quickly, and a wave moved up the front several hours later after a "lull".  Good, solid, 6"+ moderate event in about a 6-8 hour period that day!  Again, a rare case I'm sure along with a certain amount of good luck.

[PDIII]

1 hour ago, midatlanticweather said:

This is a bit helpful. Knowing patterns will help. You get pretty good descriptions from Psu and chill that help! https://www.google.com/url?sa=t&source=web&rct=j&url=https://www.abington.k12.pa.us/teachers/hurmms/Majorsnowstormchecklist_files/Stormchecklist.ppt&ved=0ahUKEwiyyNDH5O7RAhXJfZAKHfxCAU44ChAWCCIwAw&usg=AFQjCNH8x7HlChuJKTLaB0zYLMyZQMSxCQ

This is Awesome.  Thank you !

[Isotherm]

Repost from NY forum, but I have been liking the trends w/ strat and other variables for mid feb onward. Nothing is guaranteed but it is more legitimate than anything I have seen so far this winter.

 

While it would be ideal to propagate upward and split through 10hpa, it isn't really necessary insofar as the induction of tropospheric blocking (primary difference would probably be a longer duration block if it splits throughout the column). Since this is a wave 2 upwelling event, positive changes at the surface are more likely to occur than waiting patiently for a typical downwelling event. This is the first time I have actually liked how the EPS look in the LR. The NAO is too far NE initially, but once it retrogrades slightly further west, the trough will be in the Northeast, regardless of the positive EPO. The PNA will improve concurrently due to tropical forcing aid. I would also target the 15th to 20th general period for something interesting. Overall, I still like what I see down the road.

[87storms]

I heard it's gonna snow next Winter.