leo2000

I think that's unlikely based on what happened last Christmas I can see it being similar. Plus, I think we are going to an early SSW locked in for size weeks starting around first week of December last into mid January then the annual January thaw the pv reconsolidating and the some weaker again of the pv allowing for stretching of the pv but no more SSW but will allow winter cold and snow to return.

The only way for that to happen I think is through a positive PDO/positive TNH pattern.

To Bluewave- A negative IOD apparently can change the pattern, the eastern USA may see an increase in snowfall or precipitation, as the combined effects of a negative IOD and La Nina can enhance atmospheric moisture and create favorable storm tracks. To Snowman- While the blob is cooling its such a large blob and the longer it's out there the more the impacts will be felt across the northeast USA and eastern Canada with plenty of cold and snow.

Yeah but that is an historical marine heatwave in the north Pacific. Sure yes doesn't look like it will bring a prolonged +TNH but with the forecast being neutral enso for the second part of winter it's a toss up.

The big reason why I am optimistic about this upcoming winter is the north Pacific warm blob. The last time this happened back in in 2013 we all know what followed.

I ain't following all this La Nina non sense about it being moderate. This is a neutral enso winter not La Nina or El Nino. https://wmo.int/news/media-centre/la-nina-may-develop-it-likely-be-weak-and-short-lived

Just keep the MJO in the circle as all its wants to do is go into phase 6.

Not the kind of news I would like to hear. The GEFS has been doing very well with the MJO sadly. But there is a caveat perhaps we get a big displacement of the TPV that would overwhelmed the MJO signal. Oh i forgot to add ensembles and Euro Weeklies are showing the colder pattern returning early to mid January. The pattern that came in early December muted the MJO signal when it was in phase 6 will probably again. I think when the colder pattern comes back this time it could come back for much longer than last time and with abundant moisture.

I was seeing that as well. But looks like the PV will not consolidate as it will break up once again in two pieces. https://www.tropicaltidbits.com/analysis/models/?model=gfs-ens&region=nhem&pkg=z500a&runtime=2024121512&fh=354. I go with the GEFS on this as the EPS is not good with the PV and the MJO. The GEPS showing the same thing as the GEFS. https://www.tropicaltidbits.com/analysis/models/?model=gem-ens&region=nhem&pkg=z500a&runtime=2024121512&fh=348

The thing is the GEFS has been more right about the MJO progression then the EPS has. Just look at what the 12z GEFS is showing at the end. https://www.tropicaltidbits.com/analysis/models/?model=gfs-ens&region=namer&pkg=z500a&runtime=2024121212&fh=384

Depends in a La Nina Background state MJO phaase 6 is cold in the east.

Air model of the Euro is showing cold dominating through the second half of December as well as there has been hints of it on some of the GFS op models and Euro ensembles. Especially the perioa bid of 20-23 december at least. With that type of pattern setting up I can see it establishing itself as a long stable pattern persisting into a good part of January. Then I think we will get a break, the polar vortex will have taken a significant blow to itself allowing a big displacement of the vortex in early February.

In earlier runs the trough was retrogressing towards the Aleutians a few days before Christmas. not saying that will happen but I am not writing it off yet. Coastalwx, of course they do but its interesting its still showing colder outcomes before Christmas and continuing into Boxing day.

Never seen so much flip flopping before. I think the models are having a hard time capturing the pacific pattern which I think should based on the Wpac temporarily cooling off should allow for more -EPO, -WPO and more +PNA.

I don't know about that a lot of model flip flopping going on from ugly to good then back to ugly. The days before Christmas are up in the air on what is really going to happen.

Just might get a white Christmas after all MJO speeding through phase 6 to 7?.

That is that positive EPO Vortex going to be hard to get rid of that. Let's hope that doesn't happen Christmas is cooked then. I am trying to hold out hope.

Not to sound the alarms just yet but their are strong signals for a big storm around the 22nd of December as a trough tries to establish itself with cold air around too. You can see it on the GEFS and the EPS. That pops a nice positive PNA as well. https://www.tropicaltidbits.com/analysis/models/?model=gfs-ens&region=namer&pkg=z500a&runtime=2024120706&fh=360 https://www.tropicaltidbits.com/analysis/models/?model=eps&region=namer&pkg=z500a&runtime=2024120700&fh=360

It has been showing this for days now!

No pacific ridge -EPO in that graph though. I see blue low heights near Alaska.

Not as cold as weatherbell but the lastest run had just gotten colder for the east. https://www.tropicaltidbits.com/analysis/models/?model=cfs-avg&region=us&pkg=T2maMean&runtime=2024120506&fh=1002

This is interesting more red showing up in Alaska pretty close to the end of 18Z GEFS. https://www.tropicaltidbits.com/analysis/models/?model=gfs-ens&region=namer&pkg=z500a&runtime=2024120418&fh=372

Could be anytime as 1972, 1982 was only 10 years apart. Wasn't 2013-2014 winter a good positive PDO too?.

Let's hope the GFS op models are incorrect as they are showing the ridge above AK gone in the long range. Hopefully the GEFS ensembles don't follow suite.

Source from Bamwx Big colder trends on the mid-day GEFS - a step towards our forecast of staying COLDER through Mid-December vs. warmer weekly data.