Holston_River_Rambler

Wonder which PV he's talking about in the above? Stratospheric or tropospheric? #PolarVortex doesn't make it clear. It's almost as if he's looking for clicks or something. A strengthening -NAO can put pressure on the SPV and the TPV. Example from 0z Euro: I chose 30mb because that pressure level is lower and closer to where the potential -NAO is forming. The same processes that are helping to create the -NAO on the recent deterministic runs are also fluxing heat poleward at the tropopause. 500mb: Tropopause: Pac jet doesn't look terrible to me in deterministic progs. Right now, yeah, that's not good: We never really want to see it all the way across the Pac. But going forward, looks buckly to me. Of course that and anything can and will change. I'm encouraged this AM by the OPs finding the -NAO again and that wavy pac jet look. I seen years where that jet was just a fire hose all the way across the Pac in to California.

Here be ye olden control: MrGolfman, here ye go, the weeklies mean:

Someone posted on southernwx that the extended Euro control showed a pretty good way out of this mess. I see Golfman posted the snow map above, I can throw up some gifs of the 500mb anomalies and MSLPs if there is interest.

Yeah, it's wild some of the flip flopping OPs are doing right now. Huge NAO -> No NAO-> some sort of N Atlantic blocking Meandering cutoff over the Southern CONUS -> Now just a cutter I am also glad some of the runs are starting to move that Aleutian ridge around. Hopefully once they ingest the thunder we had last night for their 12z runs, things will start to move around even more

Sorry about that: https://mesonet.agron.iastate.edu/current/mcview.phtml?prod=usrad&java=script&mode=archive&frames=400&interval=60&year=1995&month=12&day=25&hour=0&minute=0

I was trying to pull the radar imagery from IEM as gif, but the file won't process. Here's a link if anyone wants to check it out: https://mesonet.agron.iastate.edu/current/mcview.phtml?prod=usrad&java=script&mode=archive&frames=400&interval=60&year=1996&month=12&day=25&hour=0&minute=0 I think most folks who were alive at that time in upper east TN and SW VA know where the pattern ends up about Jan 7 - 8, 1996.

That definitely looks better, but as far as I can tell, there's nary and Aleutian ridge o' death to be seen I had to go back to early December 1995 to see something similar:

I got this one from the NCEP reanalysis site for todays date in 1995:

We desperately need to fill up the thunder in the mountains index. There is hope tonight.

Interestingly both GFS AI and Euro AI both almost look like ensembles for the same period. Since they are machine learning models using (presumably and I could definitely be wrong) the continuity of typical patterns, I wonder if the AI models skew less amplified in the longer range, since dramatic and amplified events are somewhat rare? Would this make the AI models less useful in the medium to longer ranges until they have ingested more datasets of times where large blocks are "bullying" (quoting griteater) the pattern? How many significant, blocky patterns have wee seen since we started running AI models to give them datasets? I would say not many over the regions depicted below, but don't often look at blocky patterns anywhere else, so there could be some confirmation bias at play.

6z GFS shows a similar evolution waaaaayyyyyy out in fantasy land to 0z Euro for NC and southside VA. When people root for NAOs to impact the pattern, that's the sort of thing I want.

Good question. That's something I'd like to figure out: how to read via satellite to see where impactful tropical convection is (for the pattern over N.America in general and the TN Valley in particular) and how it that convection is evolving (moving, increasing, and decreasing) to potentially modulate weather in extra tropical regions.

No worries at all. I've been trying to think of some way to contribute, but I'm kind of burned out on looking at tropical convection, lol.

I've been thinking about weighing in on the MJO stuff, but I'm not really sure what I make of it. This sort of mess is new to me: For what seems like most years lately, its been doing this loop d loop mess between 5 and 6. When I look at the Maritime Continent region, it basically looks how it has looked to me for most of the times I've looked at it over the past few years: Sahara satellite just because it is so fun: So what are we looking for wrt tropical convection and why? I can look at the RMMs as well as anyone and see where it is, but I'd like to start to dig deeper. I'm going to poke around in this article for a while and see if I can come up with a useful summary: https://journals.ametsoc.org/view/journals/wefo/29/1/waf-d-13-00102_1.xml

Heck if I know a good answer for either of the above. Sorry. That could be interesting. There has been some on again, off again talk about a potential -NAO across the boards, depending on your source based on either wave breaks in the N. Atlantic or strat. stuff from around a month ago. Could be a little bit of both. If an Greenland block kisses an Aleutian block we might get some fun as suggested in fantasy land on the 18z GFS: 500mb: The surface has fine looking Canadian high dripping down into the CONUS: One thing about this pattern is that it's blocky is some spots in the N. Hemisphere, not just the Aleutians. I have some family in Europe right now, so I have been watching there a little more than usual and they have some intersting patterns progged by the Euro and GFS: Could you imagine if we had a pattern like that in the US? Highs over top and a series of meandering lows to the south.