40/70 Benchmark

Absolutely buy....that is the Pacific trough regime I expect to take hold around Xmas and through the first half of January that should flip to +TNH mid month.

Expect the hostile trend in the polar domain to continue for later in December.

I would expect about a mean of those 3 seasons...maybe add in 2005.

You never answered my question on FB...How did you do in December 2000, 2007 and 2008?

You can tell Tony is panicking because he keeps emphatically questioning anyone who isn't sold on a wintry December.

Could also throw 2001 in.

Maybe a compromise??

Just as you argue the SSW is unlikely to be as impactful, I would also argue that February is unlikely to be as warm and the reflection event will last longer. Notice that 2018 was on the shorter end of the spectrum...

Don't underestimate the ability of +TNH to linger into February. Here is a list provided by Lee at al (2019) of the most prominent reflection events of the past 45 years, including the primary analogs of 2001 and 2018. Courtesy Lee et al 2019 The mean length of the process is 20 days, with 10 days being the minimum, and 60 days the maximum, per Lee et al (2019). Considering the length of the 2001 (33 days) and 2018 (20) events, it as expected that a reflection event will begin between approximately January 13th and 16th 2026, and end between about February 2 and 18th.

MJO doesn't look to be much of a factor for early January, as will probably enter the COD by Xmas, so we are going to be left with a consolidating PV and PT regime.

This is also supportive of a +PNA January.

I don't think January will be cold in the mean because the second half cold will largely serve to negate the first half warmth. I think February and/or March will be colder.

Yea, but the PV isn't stout, either....you don't need February 2010 blocking to slide just under neutral in the monthly mean (NAO). This will be a good snowfall pattern for NE, but not the mid atl...agree. No KUs, but rather a series of moderate snowfalls owed to WAA/SWFEs. January will be the +PNA mismatch month this season....take that to the bank.

Another interesting tidbit about the modern climate that @Stormchaserchuck1has pointed out is the tendency for -NAO intervals to coincide with -PNA.....which is important considering there should be some -NAO episodes early on. I think there was also a graphic he posted concerning the negative correlation for the following December after a strongly +PNA (last year)....not to mention the GLAAM being significantly more negative than last year. This dove tailed nicely into my expectation for a rapid recovery of the PV and lead into a January reflection event triggering a mid season +TNH pattern.

TBH, I was nervous that I should have incorporated more of the December 2000 MJO behavior (phase 8) and gone colder, but I have learned to err on the side of caution with respect to that in this modern era (see Bluewave).