December 2021 Medium/Long Range Discussion Thread

[Ji]

People forget we wasted this for a month in O1/02 
2 storms got suppressed. One phased late. One missed just northwest of us and a good overrunning setup under performed and de amplified as it got to us. But we got about as unlucky as possible from early December to Mid January. Then the bad pattern set in late January and so it was game over. 

One point specific to those other scenarios  2001/2 that look set in early December and broke around Jan 15.  If we repeat the same pattern but start around Xmas I like our odds better.  2018 we also got unlucky with a pretty good longwave pattern for about a month. But we never got much Atlantic help. In a Nina that’s huge.  The NAO is even more important in a Nina to slow down the fast NS and force it to dig and amplify under us. It’s really hard to get a significant snow here absent blocking in a Nina. So if the Atlantic cooperates some I’d like our chances more than Dec/Jan 2018 also.  But when I say that I just mean our chances to get a decent storm and make this year an ok one.  My bar is pretty low.  But it will still come down to luck  
I think some don’t like when I point out “luck” because some like to try to find reason and certainty and some think I’m excusing bad forecasting. But what I’m really doing is admitting we don’t have the skill to discern the meso scale factors that will determine one locations snowfall results at any range. We can try to identify some general longwave characteristics that will increase or decrease our probabilities at longer leads. But then we need the details to break our way and since we don’t yet have the ability to account for those little discreet details we label them “luck” or chaos. I don’t know if we will ever have the ability to accurately account for every little factor at long ranges (I kind of hope not) so for now calling it luck is good enough for me. 

It was a big one

[Ji]

It was a big one

https://www.google.com/url?sa=t&source=web&rct=j&url=https://www.weather.gov/media/lwx/stormdata/storm0102.pdf&ved=2ahUKEwjF5qL90d70AhVhj4kEHaCBCuIQFnoECBkQAQ&usg=AOvVaw0Lic4dNLpmDVgV17CyW5IB

[CAPE]

8 minutes ago, WxUSAF said:

I remember how that pattern developed in 17-18. Looked like an amazing overrunning pattern at range and the models were keying in on a storm from D8-10, but then the cold push overwhelmed it and it was suppressed to hell and gone. We got a couple minor events in a cold and dry period. 

That was the pattern that produced the bomb cyclone I think. One of those 'bad luck' deals for most of the subforum.

[poolz1]

22 minutes ago, WxUSAF said:

I remember how that pattern developed in 17-18. Looked like an amazing overrunning pattern at range and the models were keying in on a storm from D8-10, but then the cold push overwhelmed it and it was suppressed to hell and gone. We got a couple minor events in a cold and dry period. 

My memory is terrible when it comes to past patterns and even minor/mod events.  But, that fantasy overrunning event depicted on the models was droll worthy and is etched in my memory.  Would love to see an event like that really unfold.  For folks with better memories, what past event looked most like that fantasy set up?

[StormchaserChuck!]

3 strong cold waves around -NAO on 15day models for 5 straight runs now.  I like it, 4 waves around -NAO, we'll get a snowstorm if it happens like this. Last 3 models runs have been cold in the NE. 

[StormchaserChuck!]

2 hours ago, psuhoffman said:

People forget we wasted this for a month in O1/02 

97-98 had a -NAO period, too.. our 2 least snowy Winter's. This LR -NAO if it happens like on models will make 22 straight -NAO's with a -PNA or +EPO, going back to 2018.. the West to east jet stream has tremendous power. 

 

[BristowWx]

4 minutes ago, BristowWx said:

GEFS looks decent so far through 258 at h5 up top

 

[Solution Man]

22 minutes ago, BristowWx said:

 

Perhaps we are headed in a favorable direction

[Eskimo Joe]

 

[BristowWx]

15 minutes ago, Solution Man said:

Perhaps we are headed in a favorable direction

No idea…to my eyes All it’s doing is keeping it less above normal really…keeping the ridge less amped in the SE…its hard to get too excited as we move toward the end of the month with no solid prospects for anything interesting…my 2 cents …

[Weather Will]

WB 12Z GEFS

[SnowenOutThere]

4 minutes ago, Weather Will said:

WB 12Z GEFS

Lock in p15

[Ralph Wiggum]

2 hours ago, StormchaserChuck! said:

3 strong cold waves around -NAO on 15day models for 5 straight runs now.  I like it, 4 waves around -NAO, we'll get a snowstorm if it happens like this. Last 3 models runs have been cold in the NE. 

Not sure you can guarantee a snowstorm, but one of your brief and better informed posts.

[Ralph Wiggum]

Ops beginning to see the threat centered around Dec 22. STJ energy meandering East, transient PNA ridge popping, neg NAO. Brief window but in a Nina these opportunities are what we look for. Probably the first real threat so far in the overall Nina pattern. 

[Ji]

Ops beginning to see the threat centered around Dec 22. STJ energy meandering East, transient PNA ridge popping, neg NAO. Brief window but in a Nina these opportunities are what we look for. Probably the first real threat so far in the overall Nina pattern. 

We need a 5050 low

[SnowenOutThere]

Remember how we thought the last snow chance was going to be far too amped at long range, then it died to suppression. We have to remember that things won't ever end up the way they are 7 + days out. So don't worry on the specifics of the possible storm early next week, it's just not worth it. Once we get to Thursday we can take it more seriously.  

[Ralph Wiggum]

26 minutes ago, Ji said:

We need a 5050 low

 

[CAPE]

2 hours ago, Ralph Wiggum said:

Ops beginning to see the threat centered around Dec 22. STJ energy meandering East, transient PNA ridge popping, neg NAO. Brief window but in a Nina these opportunities are what we look for. Probably the first real threat so far in the overall Nina pattern. 

This has already been established as the CAPE storm. I take no responsibility for complete failure however.

[Ralph Wiggum]

6 minutes ago, CAPE said:

This has already been established as the CAPE storm. I take no responsibility for complete failure however.

Is this what TWC is calling it? 

JMA on board....probably the best look so far:

[mattie g]

5 hours ago, poolz1 said:

My memory is terrible when it comes to past patterns and even minor/mod events.  But, that fantasy overrunning event depicted on the models was droll worthy and is etched in my memory.  Would love to see an event like that really unfold.  For folks with better memories, what past event looked most like that fantasy set up?

Is that the one which was showing a massive stream of moisture coming out of the Southwest and running over a deep layer of cold air for days on end?

[Eskimo Joe]

1 minute ago, mattie g said:

Is that the one which was showing a massive stream of moisture coming out of the Southwest and running over a deep layer of cold air for days on end?

Yea that hurt having that pulled out from under us. Even I was starting to believe.

[poolz1]

23 minutes ago, mattie g said:

Is that the one which was showing a massive stream of moisture coming out of the Southwest and running over a deep layer of cold air for days on end?

That is the way I remember it looking.  Cold smoke with a crazy gradient to our south and an endless moisture stream from the SW.  One can dream... 

[psuhoffman]

47 minutes ago, Eskimo Joe said:

Yea that hurt having that pulled out from under us. Even I was starting to believe.

 

22 minutes ago, poolz1 said:

That is the way I remember it looking.  Cold smoke with a crazy gradient to our south and an endless moisture stream from the SW.  One can dream... 

We should have dismissed that just on the fact there are no comps. The only thing that came remotely close to what models were spitting out in Dec 2017 was PD2 but that wasn’t as long duration, did have a more concentrated system, and was in a Nina.  

[Chris78]

27 minutes ago, poolz1 said:

That is the way I remember it looking.  Cold smoke with a crazy gradient to our south and an endless moisture stream from the SW.  One can dream... 

I believe the gfs was showing a 3 or 4 day event with insane snow totals. 

I don't think it got inside of 5 days though on the models, but it was on there for several days out in fantasy Land if I remember correctly. 

 

[chris21]

9 minutes ago, psuhoffman said:

 

We should have dismissed that just on the fact there are no comps. The only thing that came remotely close to what models were spitting out in Dec 2017 was PD2 but that wasn’t as long duration, did have a more concentrated system, and was in a Nina.  

That ended up being an epic surprise storm for my current location at the time, Candler, NC (just west of Asheville). Forecast was for less than an inch and even though short range modeling picked up on a 2-4 deal at the last minute we ended up with 11-12 inches and then an inch or so of upslope that night with blowing snow and blizzard conditions.

[psuhoffman]

7 hours ago, Ji said:

It was a big one

2002 is probably the best example of bad luck. Not saying that year should have been good. But we had a good enough pattern for enough time that it shouldn’t have gone down that badly. 1996 is provably the best example of good luck. Yea we had some good patterns (and some bad ones) but almost every threat hit!  And honestly some of the looks that created snow weren’t that amazing. Not like 2010 when the pattern really was so good that a repeat of that longwave pattern in a Nino likely would repeat those results or something close. 

[Eskimo Joe]

1 hour ago, chris21 said:

That ended up being an epic surprise storm for my current location at the time, Candler, NC (just west of Asheville). Forecast was for less than an inch and even though short range modeling picked up on a 2-4 deal at the last minute we ended up with 11-12 inches and then an inch or so of upslope that night with blowing snow and blizzard conditions.

Glad you got a hit down there. Y'all get screwed over so many times it stinks.

[mattie g]

3 hours ago, poolz1 said:

That is the way I remember it looking.  Cold smoke with a crazy gradient to our south and an endless moisture stream from the SW.  One can dream... 

 

2 hours ago, Chris78 said:

I believe the gfs was showing a 3 or 4 day event with insane snow totals. 

I don't think it got inside of 5 days though on the models, but it was on there for several days out in fantasy Land if I remember correctly. 

This is exactly how I remember it. It was there for days, but then reality set in and it disappeared. But while it may have been anomalous, it was a dream to watch it unfold on run after run.

[Ji]

I believe the gfs was showing a 3 or 4 day event with insane snow totals. 
I don't think it got inside of 5 days though on the models, but it was on there for several days out in fantasy Land if I remember correctly. 
 

Yea man...devastating loss

[Ji]

Its not likely we will see snow this month. Maybe early January