December 2021 Medium/Long Range Discussion Thread

[frd]

 

 

Interesting as well are the changes in the placement and orientation of the PV as we near the end of the month.  

 

 

 

 

 

[BristowWx]

it’s notably stable pattern on the GEFS…but through 324…it’s just stable above normal for us.  Yet when compared to past 4 runs you can see lower heights in the east post Xmas.  No idea but it’s something. It is what it is and who knows if that deep arctic air in w. Canada will move SE.  

[poolz1]

9 minutes ago, BristowWx said:

it’s notably stable pattern on the GEFS…but through 324…it’s just stable above normal for us.  Yet when compared to past 4 runs you can see lower heights in the east post Xmas.  No idea but it’s something. It is what it is and who knows if that deep arctic air in w. Canada will move SE.  

That is one impressive -NAO signal toward the end of the month for an ensemble mean. 

[BristowWx]

You can see the impressive -NAO flexing post 354 at least on this run

[BristowWx]

1 minute ago, poolz1 said:

That is one impressive -NAO signal toward the end of the month for an ensemble mean. 

You’d think the PV would just pop like a grape at this point.  

[BristowWx]

You’d think 2m temps would at least be BN by 366…nope.  

[CAPE]

15 minutes ago, BristowWx said:

it’s notably stable pattern on the GEFS…but through 324…it’s just stable above normal for us.  Yet when compared to past 4 runs you can see lower heights in the east post Xmas.  No idea but it’s something. It is what it is and who knows if that deep arctic air in w. Canada will move SE.  

It's not what I would call stable. Beginning this weekend the anomalous ridge flattens with some NS energy/chilly air impinging, so temps will go back and forth a bit. As advertised we could be generally colder by Xmas, and esp thereafter as the -NAO becomes more established.

[CAPE]

8 minutes ago, poolz1 said:

That is one impressive -NAO signal toward the end of the month for an ensemble mean. 

This is kinda pretty. 

[BristowWx]

2 minutes ago, CAPE said:

It's not what I would call stable. Beginning this weekend the anomalous ridge flattens with some NS energy/chilly air impinging, so temps will go back and forth a bit. As advertised we could be generally colder by Xmas, and esp thereafter as the -NAO becomes more established.

You’re right.  Impressive -NAO for sure this run.  

[poolz1]

2 minutes ago, CAPE said:

It's not what I would call stable. Beginning this weekend the anomalous ridge flattens with some NS energy/chilly air impinging, so temps will go back and forth a bit. As advertised we could be generally colder by Xmas, and esp thereafter as the -NAO becomes more established.

I was just thinking that it looks like we may have a false start to this pattern next week, warm up a bit for the holidays (of course) and then the pattern becomes better established.  

[BristowWx]

That was an inspiring GEFS run.  That -NAO doesn’t look transient to this untrained eye.  It looks as stable and sprawling as my mother in law on the couch on Xmas

[psuhoffman]

1 hour ago, WEATHER53 said:

Really

This Again?-pattern change just a month away. Probably the most over stated yet under occurrent statement that gets made here, along with the 360 GFS always showing a big winter event 

 

 

On 11/24/2021 at 11:07 PM, WEATHER53 said:

I think we are In the favorable two months mostly below average trait DC displays. Not April May or Sept Oct this time. So we got from now until about 1/1/22-1/15 .

 

They can’t be worse than your call.  I was wrong about December also…but I don’t go around throwing stones…

[frd]

22 minutes ago, CAPE said:

This is kinda pretty. 

 

 

Fits @brooklynwx99 's roll-forward West based - NAO research. Pretty cool ! 

[StormchaserChuck!]

Honestly, -PNA with strong -NAO is not that bad. We do best snowstorms with GOA Low which is -PDO pattern. Problem is probably the STJ. -360dm on a 372hr average of 25 ensemble member is strong. 

[Yeoman]

1 hour ago, BristowWx said:

You can see the impressive -NAO flexing post 354 at least on this run

Damn.. if it were only within 330 hours I would get excited

[Ji]

Damn.. if it were only within 330 hours I would get excited

Its amazing how we never have to wait 384 hours for warm

[clskinsfan]

MJO enters 8 on Christmas day. Merry Christmas!

http://www.cpc.ncep.noaa.gov/products/precip/CWlink/MJO/diagram_40days_forecast_GEFS_member.gif

[Maestrobjwa]

So...what's the over/under on ninas with a -NAO?  (that actually have cold air to work with, that is)? Make any difference? Or is this to specific of a thing to look at?

[frd]

 

Will need to watch this constructed analog progression in the weeks ahead centered on 1-13-22.   

 

 

 

[psuhoffman]

22 minutes ago, Maestrobjwa said:

So...what's the over/under on ninas with a -NAO?  (that actually have cold air to work with, that is)? Make any difference? Or is this to specific of a thing to look at?

Last year was really odd. I’ve never seen that good an Atlantic combined with that atrocious a pac. 

I’ve said before there are two types of Nina’s. Ones with a flat pac ridge and ones with a more poleward ridge. The ones with a flat ridge typically are warm and ugly wrt snow.  if you imagine the flow in the map above its straight across the pac and enhanced by gradient between the flat ridge and the vortex to its north in the wpo and epo domains.  That’s as ugly a pac as possible. 
 

What's odd is those Nina’s typically don’t feature much blocking. That kind of pac isn’t very conducive to a -NAO. Usually that kind of enhances zonal flow in the pac will destructively interfere with attempts at blocking. 

But we got some of the best blocking of the last decade. A very odd combo. And the blocking did save us from a year like 2008 or 2012.  We had way more chances and places not far NW of 95 did ok. That isn’t true in a typical flat pac ridge Niña where it’s common to see little snow until you get well into New England.  But that dreadful pac prevented a good winter. 
 

This year the pac ridge isn’t flat it’s been poleward and projections continue that base state. Look at the gefs for the end of the month. 

The north pac is completely reversed from Last year.  The ridge poleward alters the flow.  Now the flow into the conus is from the arctic not off the pacific.  
 

This type of Nina also is more typically linked with blocking. The poleward ridge transports more heat into the high latitudes and disrupts the polar vortex making blocking more likely.  
 

If the pac ridge remains poleward AND we get some blocking we should get a colder outcome then last year.  Dry and miller Bs are still a way we can fail in that look but lack of cold not as much.  
 

This is the setup I expected to get at least some point this winter and why I went with below avg snowfall but not way below and a more decent outcome for a Nina.  But luck will have a say.  We will get chances but we have to score on some.  

 

 

[yoda]

49 minutes ago, frd said:

 

Will need to watch this constructed analog progression in the weeks ahead centered on 1-13-22.   

 

 

 

Can someone explain this please?  Thanks :)

[jaydreb]

Well the GFS is interesting.  
 

[Maestrobjwa]

4 minutes ago, jaydreb said:

Well the GFS is interesting.  
 

No it ain't! Don't worry the squash foot is a-comin...euro run from earlier probably has the right idea.

[jaydreb]

3 minutes ago, Maestrobjwa said:

No it ain't! Don't worry the squash foot is a-comin...euro run from earlier probably has the right idea.

Of course, but it’s always nice to see the blue over us. 

[Maestrobjwa]

1 minute ago, jaydreb said:

Of course, but it’s always nice to see the blue over us. 

Our responses to fantasy snow are interesting...When we see it on a run, it's almost like, for a moment, we can almost feel it happening. That excitement/the good feels...I guess that explains the angst over the digital "snow" being "taken away" in a future run. A strange psychology...lol

[Weather Will]

WB OZ GFS….BELIEVE…if only for 6 hours,

[Weather Will]

WB OZ Can big shift this run toward GFS solution…BELIEVE…if only for 6 hours,

[yoda]

At least we got it to Day 7 lol

[yoda]

54 minutes ago, jaydreb said:

Well the GFS is interesting.  
 

Get that HP a bit further west and we in business 

[Weather Will]

WB OZ EURO, nice jog toward GFS,  BELIEVE…. Long time since I have woken up for the EURO and not been depressed….