andyhb

Did some skimming of SSTA data tonight and I'm intrigued by that warm pool centered at ~150˚W and 30˚S to the south of the cold SSTAs with the Nina. Based on looking into some previous analogs around this time, it seems like that strong meridional dipole is not present in years such as 2006, 2009, 2012, 2017, and 2018 (generally quieter severe seasons especially late season). It is more prevalent in several big Nina springs though, including 1974, 1976, and 2011. It's probably to some degree why this CDAS-derived SSTA analog product from Tropical Tidbits is essentially grouping a who's who of Nina springs with a lot of tornadoes/severe weather, including some with very large outbreaks. You can see the SSTA dipole present in the Southern Hemisphere in the mean here.

This quote from TSSN12's sig via baro from GHD I.

Can you both take your crap to DMs?

Yes. This is exactly it. The confluence between the TPV dipping southeastward into Ontario and the SE ridge downstream.

The reason for lower totals further east is because of the shearing of the parent shortwave and resultant partial loss of dynamic support with time. This has nothing to do with temperatures.

The January 67 blizzard was not a phaser. It was one shortwave (more amplified than this one, but it was not a Jan 1978 type scenario).

No, it isn't. Stop clogging up the thread. This system has never been a "phaser" and it doesn't need to be for foot plus totals. The reasons why have been discussed ad nauseam over the past few days, but you continue with this borderline trolling nonsense.

2015? Sure. 2011? Not a chance in hell.

This. That would mean there's barely a shortwave left due to confluence from the ULL/TPV and the SE ridge, there would barely be a "brunt".

I don't really see how one can establish a "trend" when models keep flip-flopping back and forth, nor can I see a solution where Indianapolis gets the brunt of this.

This thread is a ****ing trainwreck right now.

They've been quackier than a duck farm for ages.

Crush job incoming.

IIRC didn't some of this get fixed in the most recent update of the GEFS? Or is that still associated with the v16 testing?

Going to be a lot of precip with this thing if the trough has any degree of amplitude upon reaching the OV/Lakes. Gulf is wide open.

It's almost as if @RCNYILWX knew what he was talking about or something...

I doubt a lot of people want winter to continue into April either.

re: Spring tornado chances. 2008/2017 would be more promising though.

Looks like Tropical Tidbits has their SSTA analogs up and running again. That would certainly be a favorable set for an active severe weather season, especially early season. On the other hand, rapidly decaying Ninas in 3.4 over the past 20 years have been very unfriendly to the Plains in peak season, as such years consist of 2006, 2009, 2012, 2017, and 2018.

Difficult to get cutters when you have a strong block over the Davis Strait.

Posting/discussing ensemble forecasts in that range is problematic how? That's what they're designed for. Also, you were the one that made a blanket statement about west-based La Ninas, not me. The point is that we haven't exactly been in a "typical" pattern of La Nina (or anything close to what you are claiming) recently. Ongoing -NAO argues against a torch, as does the potential for ridging over the EPAC/AK later in the month.

Interestingly the MEI data is tracking right along with 07-08 and 98-99 for the past 4-5 months, despite the SSTAs being quite a bit weaker through most zones. Well behind 2010-11 though, which is the strongest La Nina via MEI in the entire dataset going back to 1979. Also pretty close to 08-09 and 11-12. If we're talking severe weather season strictly looking at these four years, there's quite a divergence between 07-08/98-99 (highly active seasons) and 08-09/11-12 (much quieter ones). The latter two show a poleward retracted jet in AMJ as opposed to the former.

This is gibberish. With ridging into AK yielding a Siberian connection (dislodging cold air) and strong -NAO blocking near/over Greenland, an all out torch is highly unlikely ala 2012. Low frequency (ENSO) signal is not the be all/end all. Hell, south/central Texas got a substantial snow event yesterday, that doesn't typically happen in a La Nina year given the suppressed sub-tropical jet. Edit: I should've expanded my post yesterday to mention late January as well, since that looks to be when we will see more of a transition.

For lack of a better term, February looks like it could offer the chance for a blockbuster or two for the Lakes as the North American longwave pattern retrogrades plus continuing high latitude blocking (albeit likely relaxed some) and a more Nina-like regime resumes. Should note that with this high latitude blocking comes some degree of suppression to the typical SE ridge, and less likelihood for storms to cut west of the sub-forum. Going to have to watch severe weather chances down south I'd imagine as well.