2026-2027 Record-breaking El Nino

[jconsor]

23 hours ago, GaWx said:

 The chart below has 10 mb/60N winds back to 1949. According to it, Nov 2026 is going to per ERA obliterate the old record (all of the way back to at least 1949) earliest SSWe whether it gets down to 0 (major SSW) or stays just above. The earliest SSW on record is 1952’s ~Nov 15th SSW. So, 2026 is headed to possibly beat 1952 by ~11 days!

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 Looking at the above chart for only El Niño Novs, the only three that got to +5 or lower per ERA5 in Nov were 1968 (-5 on Nov 27th), 1976 (+4 on ~Nov 15th), and 2009 (+5 on ~Nov 15th). These three had the lowest DJF AO of any winters since at least 1949-50. Thus, these very strong winter -AOs were quite possibly connected to a large extent to the very weak Nov SPV period. Thus, a case could be made for a better than average chance for a strong -AO averaged out in 2026-7 despite the lack of seasonal model support:

1968-9: AO -2.3

1976-7: AO -2.6

2009-10: AO -3.4

@Typhoon Tip
 

*Edited for typo 

Very nice find, Larry!

While the seasonal model support for a strong -AO is mostly lacking, the sub-seasonal support is growing.  There is increasing support for a -AO in the last two-thirds of Nov.  EPS and GEFS long range weather regime charts show an increasing proportion with Greenland High (GH) or Alaskan ridge (AR) vs. prior forecasts. 

This is also reflected in individual member AO forecast charts from the long range EPS and GEFS.

Taking El Ninos of any strength, the four with a Nov AO below -1.0 saw that -AO persist overall through the winter and most of these were memorable winters with at least one KU event:

1957-58: -0.9
1965-66: -1.5
1968-69: -2.3
2002-03: -0.6
 

[snowman19]

I agree here that this is different than much of the last decade plagued by split forcing. I don't know that in the end it will mean any more snow or cold...but it is different and we shouldn't assume the last 12 years will necessarily hold this year. 

In the last 50+ years, the super El Niño that most closely resembles this one in development/evolution, forcing and orientation (even though this one is much stronger and more east-based) is 1997, hands down

[forkyfork]

remember in april when you hive members were trying to will this event under +2 because you knew it would be really bad for cold and snow this winter? now it's +3 and you're willing some kind of magic block that will defeat the pacific vortex