December Mid/Long Range Discussion

[cbmclean]

1 hour ago, Stormchaserchuck1 said:

We're in a bad decadal cycle in the Pacific (last 25 years):

https://ibb.co/nkdRM0v

And a higher frequency of La Nina 

https://ibb.co/GnzTZ0y

La Nina is up on El Nino 15-9 since we went +AMO in 1995. 

I thought El Nino vs La Nina was modulated by the PDO as opposed to the AMO.

[cbmclean]

1 hour ago, Maestrobjwa said:

Anybody care to weigh in on why we've been seeing this more often lately?

The @psuhoffman lending library has many volumes you could check out on this topic, but in your heart of hearts, you know the answer to this question already

[Maestrobjwa]

29 minutes ago, cbmclean said:

The @psuhoffman lending library has many volumes you could check out on this topic, but in your heart of hearts, you know the answer to this question already

I actually wasn't sure it had something to do with that or not. I keep seeing folks say the artic air is "kicked" or "trapped" on the other side of the globe...Now from a layman perspective, I thought that implied there was another mechanism that did that. So you're saying all the pac air kicks the colder air to the other side of the hemisphere, or?

And from that same perspective...I also don't get how "that" problem means warm or our side of the hemisphere but still cold there. May be a dumb question, but remember...non-scientifically oriented poster here. Sometimes we need a "for dummies" explanation of these things!

[brooklynwx99]

first larger storm signal this year? looks potent 

[jayyy]

first larger storm signal this year? looks potent 

Man, today was a great day for LR ensembles. Certainly a workable pattern being depicted by the Euro, GEFS, etc.. with some differences in the exact evolution of the pattern. A very active STJ and the arrival of colder air / blocking = BOOM. Just a matter of having a smidge more patience for the Atlantic and NAO to improve. We’ve seen coastal storm after coastal storm make their way up the coastline in 2023. Fully expecting more of the same this winter.

[Weather Will]

WB 0Z EPS has it too....

[CAPE]

1 hour ago, Weather Will said:

WB 0Z EPS has it too....

EPS has a better(colder) look for that window than the GEFS/GEPS, with a more amplified ridge shifted further west vs a flattish central Canada ridge.

[nj2va]

Nice to see Hs and Ls in the right place for that window on the 6z GFS OP.

[Weather Will]

WB 6Z GFS, late weekend storm did tick east this run with heaviest rain and wind.

[Terpeast]

8 hours ago, jayyy said:

Really not that gonna be that warm leading up to xmas… at all..

Yeah I was thinking the same. Not like Dec 2015 at all. 

[Chris78]

Not going to post maps lol but the OP gfs shows potential around the same time the Esembles are honking. 

It might get interesting after Christmas.

[CAPE]

2 minutes ago, Chris78 said:

Not going to post maps lol but the OP gfs shows potential around the same time the Esembles are honking. 

It might get interesting after Christmas.

Yeah a few runs in a row now. A lot would have to go right timing wise with no help in the NA, esp for the lowlands, but something to keep an eye on.

[dallen7908]

Yes, the PNA is positive during the last week of December but the NAO also remains positive.   On the positive side, approximately 25% of the EPS and GEFS members show a neutral or slightly negative NAO during the last portion of the last week of December.  I can't remember the last time there was anything to track during the December 27 - January 1st period.   Hopefully, the ensemble 500 means are on to something. 

[Ralph Wiggum]

Thing I've learned over the past several seasons....a good PAC can overcome a meh Atlantic. And more often than not a good Atl with a crud PAC does us no good. There are exceptions but I almost always look to the PAC side first before seeing what the Atl is doing. 

[Chris78]

5 minutes ago, Ralph Wiggum said:

Thing I've learned over the past several seasons....a good PAC can overcome a meh Atlantic. And more often than not a good Atl with a crud PAC does us no good. There are exceptions but I almost always look to the PAC side first before seeing what the Atl is doing. 

I agree. We don't want a raging +++ Nao but if it's slightly positive we can work with it especially as we get deeper into winter.

But I'm not necessarily big dog hunting either. If we want a HECS then sure. We need a - Nao and AO.  I just want some damn snow lol. Enough so that my kids can go sledding.

[aldie 22]

I miss the old fashioned 2-4" 3-6" snows don't get me wrong i love the big dogs but a couple of 3" storms would go a long way for morale around here I bet.

[wxdude64]

3 minutes ago, aldie 22 said:

I miss the old fashioned 2-4" 3-6" snows don't get me wrong i love the big dogs but a couple of 3" storms would go a long way for morale around here I bet.

^^ This 100% ^^

[TSSN+]

One serious deluge. Anyone opening a thread? 

[Ji]

30 minutes ago, dallen7908 said:

Yes, the PNA is positive during the last week of December but the NAO also remains positive.   On the positive side, approximately 25% of the EPS and GEFS members show a neutral or slightly negative NAO during the last portion of the last week of December.  I can't remember the last time there was anything to track during the December 27 - January 1st period.   Hopefully, the ensemble 500 means are on to something. 

yea usually that is a death week--

[Solution Man]

2 minutes ago, aldie 22 said:

I miss the old fashioned 2-4" 3-6" snows don't get me wrong i love the big dogs but a couple of 3" storms would go a long way for morale around here I bet.

Those events were good ole days. How many days since a Winter Storm Watch or Warning for the DC Metro. I know west of Hwy 15 has had a few. I think we are jaded.

[brooklynwx99]

1 hour ago, CAPE said:

Yeah a few runs in a row now. A lot would have to go right timing wise with no help in the NA, esp for the lowlands, but something to keep an eye on.

what’s interesting is that the central Canadian ridge actually leads to HP in a good spot since it leads to NVA aloft. so, it can provide confluence even if it’s in an unorthodox way

[Eskimo Joe]

7 minutes ago, Solution Man said:

Those events were good ole days. How many days since a Winter Storm Watch or Warning for the DC Metro. I know west of Hwy 15 has had a few. I think we are jaded.

Quick search shows no Winter Storm Warning for DC since 2019. Could be wrong.

[cbmclean]

29 minutes ago, Ralph Wiggum said:

Thing I've learned over the past several seasons....a good PAC can overcome a meh Atlantic. And more often than not a good Atl with a crud PAC does us no good. There are exceptions but I almost always look to the PAC side first before seeing what the Atl is doing. 

Yeah but based on PSU's findings it appears that the NAO may be more important in the average west-based Nino because it helps modulate the alwaye Nino tendency to inject Pacific air into NA.

I agree that in Nina the PAC is an absolute.  If it is flooding us with Pac Puke then forget the NAO.  If we have a nice EPO or PNA ridge, then perhaps the NAO is of less consequence.

[cbmclean]

Actually what I think I have learned is that THE critical factor is always whichever one sucks for us at a given time.

[SnowenOutThere]

6 minutes ago, Eskimo Joe said:

Quick search shows no Winter Storm Warning for DC since 2019. Could be wrong.

What about Jan 3rd 2022? 

[CAPE]

5 minutes ago, brooklynwx99 said:

what’s interesting is that the central Canadian ridge actually leads to HP in a good spot since it leads to NVA aloft. so, it can provide confluence even if it’s in an unorthodox way

It's not there on the GEFS, and the track looks too far N/inland. EPS suggests a track right along/off the coast with HP to the NW, LP over Atlantic Canada. Surface temps are colder. Long way out so plenty can change but we are gonna need some cold for this not to be just another rain event.

[Eskimo Joe]

Just now, SnowenOutThere said:

What about Jan 3rd 2022? 

It was a quick search on the IEMbot website, but that didn't come up as a warning for the District.

[cbmclean]

17 minutes ago, TSSN+ said:

One serious deluge. Anyone opening a thread? 

Man I hate seeing rain in Quebec in mid/late December.

[brooklynwx99]

4 minutes ago, cbmclean said:

Yeah but based on PSU's findings it appears that the NAO may be more important in the average west-based Nino because it helps modulate the alwaye Nino tendency to inject Pacific air into NA.

I agree that in Nina the PAC is an absolute.  If it is flooding us with Pac Puke then forget the NAO.  If we have a nice EPO or PNA ridge, then perhaps the NAO is of less consequence.

i can pretty much guarantee that if we see a strong -NAO there could be a prolific period as long as the Pacific isn’t absolute garbage. we are seeing a strong STJ and zero indication of any persistent SE ridging 

[WxUSAF]

So for argument’s sake, let’s say the ensembles are currently correct and we get a mean trough over us around Xmas or so. How far off is that from expectations 10 days ago? A couple days? Maybe 5 at most? Rough outcome for the never ending torch crowd.