40/70 Benchmark

March 2015 $hit the bed for my area...everything supressed into the southern half of the region...was cold and dry as the epic pack slowly fossilized and eorded. Cost me a seasonal snowfall record that I was sure I was going to get.

"Most"....right...not all. I actually did a very good job of doing so in relation to that particular forecast, as I never "took the cheese", so to speak. The PNA ridge was displaced too far west and off of the coast, as it was for most of the season. https://easternmassweather.blogspot.com/2025/02/major-storm-threat-next-week-likely-to.html

I guess I should have said "averaged very positive throughout February"....that is what I meant. My bad on that.

There was a brief period -NAO mid month...I didn't say the entire month was negative. There have always been a favorable several day windows that failed to produce...I'm not sure that warrants disregarding the NAO index. Maybe you are right and we shouldn't bother factoring in the traditional NAO value when forecasting storms, but I'm not ready to make that leap.

Chris, I am not arguing that your claim has no basis or validity, but I think there is some overattribution going on there.

I actually think the best example of a the PAC jet screwing the pooch was in January. This is especially true given the presence of stronger than average Pacific jet, which combined with +NAO in the seasonal mean made it extremely difficult to sustain a +PNA ridge in the proper location long enough to facilitate the development of a major east coast snow storm. Here is a prime example from last winter of the Pacific jet undercutting a +PNA ridge and this tilting it positively, leading to a failed phase attempt on the east coast. This was a theme of the season.

The NAO was extrmeley positive throughout February (WPO neutralized a bit at .32), which is not hostile to the interior NE, but it is for the coast....lo and behold, this is precisely what materlized. Go figure- The predominantly positive NAO during the month resulted in a southwest flow event character to the vast majority of storm systems. As a consequence of the +NAO initially forcing the lobe of the PV post split to drift westward, not only was the bulk of the cold relegated to the high plains, but the signature storm of the month tracked to the west of the area. This limited the extent to which snowfall could exceed normal relative to if the NAO had been negative.

February 2015, which is when the vast majority of the record snows fell that season, featured a -1.37 WPO. (-33 DM value). This past season had a +.45 DM WPO value. The state of the west Pacific will certainly render -NAO less effective.

I didn't say, nor imply that it was all about the NAO.....2015 was a more favorable pattern and featured a deeply negative WPO, which you omitted from my "+NAO and +WPO" reference. Again, the pattern is simply more hostile....I have asked you before to find me a strongly +NAO AND +WPO season that featured well above normal snowfall along the east coast. A positive +WPO is every bit as conducive to inland storm tracks as a storngly +NAO. Now, maybe this pattern is worse than it would have been 70 years ago...I don't doubt that, but this pattern still would have sucked 70 years ago. +WPO & +NAO Correlate to Warmth for Most of the NE and Inland Storm Tracks

Okay, I agree CC is enhancing this..I thought you were implying that the Aleutian ridge has increased more than ambient heights. My only conention regarding the last part is I still think the +NAO and +WPO are playng a significant role in the low snowfall, but I don't argue that the stronger jet is having some influence as well. But it is has been a shitty pattern, regardless....+NAO/+WPO has never ended well for the east coast snow enthusiast.

Heights are rising everywhere due to CC....not sure what that proves, as it isn't specific to the Aleutian ridge.

Yea, because there are some extremely high peaks in the northern plains....

1998 is when the multidecadal PDO cycle flipped negative, so makes sense...probably augmented by CC (west Pac warm pool), too.

We must be turning into a tropical rain forest this decade.

It was also evident in Chuck's correlation maps, too....+NAO signal peaked 2 years post max...so I think we are porked with respect to the polar domain for the next couple of winters. Its not a death knell, as there are ways around that, but it certainly makes the path to a good winter more elusive.

This implies that winter 2025-2026 and 2026-2027 will be more favorable for a stronger polar vortex than last winter, which is also consistent with other recent studies of seal level pressure patterns that revealed a +NAO pattern lagging solar max by approximately 2-4 years.

Traditionally, research correlated high levels of solar activity near solar max, as was the case for winter 2024-2025, to a stronger polar vortex and thus milder winters for much of North America and Europe. There are a multitude of theories as to why this is the case, however, most of these theories cite drivers such as UV radiation and total solar radiation (TSI), which closely mirror sunspot activity, as responsible for increasing ozone levels and temperature in the equatorial stratosphere. This warmer tropical stratosphere then results in a stronger latitudinal gradient and a cooler polar stratosphere (stronger polar vortex) via a modulated Brewer-Dobson cycle. The issue with these theories is that the peak levels of the aforementioned potential drivers of the solar-stratosphere connection coincide with solar max. And most recent research cites stronger drivers that do not coincide with solar max, such as geomagnetic energy and solar winds, which peak during solar flux or, about one year after solar max in terms of peak UV and TSI . (Maliniemi et al, 2014). Malimiemi et al theorize that geomagnetic energy makes its way into the polar region via the process of energetic particle precipitation, which then produces nitrogen oxides in the the upper atmosphere that have a protracted period of time to descend downward and increase ozone during the polar winter in the absence of any sunlight, which cools the stratosphere and strengthens the PV. This more closely corroborates both with other recent research, which cites drivers that do not peak at solar max as defined by UV and TSI (geomagnetic energy peaks approximately one year after solar max), as well as the research of Malimiemi et al (2014), which found that the declining phase of the sunspot cycle remarkably consistently produces the spacial pattern of surface temperature anomalies related to the positive NAO during the last 13 solar cycles" (Maliniemi et al, 2014). This makes sense since the geomagnetic energy peak that Maliniemi et al cite as the main driver behind the connection between the solar cycle and polar domain lags solar max as defined by UV, TSI and sunspots by approximately one year, which is during the declining phase that so strongly correlates with the +NAO response in their research.

Descending is worse than solar max for the NAO, so that isn't going to help....not saying that you were implying it would....just as an addendum.

Yea, that is resonable, although I have not closed the door on a weak warm ENSO episode...albeit looking less likely than it was a couple months ago.

I interpret that as only really having much utility at all for February, which isn't much of a news flash that February will have shitty climo if we repeat cool ENSO. I guess I don't interpret this as being as telling as you and Chris do. But like I said, with you lock-step on the NAO. That said, I won't be shocked if next season is RNA....so not necessarily arguing against that. I do think we are in for more PNA moving forward, though....regardless of what happens next year.

Yea, I think once we get beyond 2026, it becomes less hostile for -NAO, but +NAO still favored until we hit the min early next decade. The ascending portion of the cycle is best for -NAO.

I'm pretty pessimistic for the NAO the next few years....descending solar sucks. Only caveat being is if we hang near solar max for awhile, maybe we can stave of the dispersing of the geomagnetic particles by the solar wind, which is what porks the NAO.

I mean, I certainly won't be stunned if next winter is -PNA....all I mean is the days of troughs down to the baja in the seasonal mean are gone for awhile. I think last season was a sign of change....maybe it's a one step forward, two steps backward (next year), but times are changing.