When will the AMO enter a cold phase and will we actually return to pre-1995 levels of activity?

[Dean_175]

Nobody knows the exact answer to this. AMO cannot be predicted by models and there is still some debate as to whether or not AMO even drives the observed activity "cycles". There is even more debate with regards to how climate change will impact this.

Now that I got all that out of the way:

1)When do you think that the AMO will enter a negative phase again?

2) When the AMO enters a negative phase, will we actually see 30 full years of mostly low activity? This question is more debatable because of how long the AMO cycle is. Technology for observations and remote sensing has improved so much over the last century (understatement) that it is difficult to make precise statistical comparisons between the activity of warm and cool phases. There are some prominent researchers who have questioned the very idea of an "active phase"- including Kerry Emmanuel.

What is your opinion? 2020 is the 26th season of the "active era". Do you think we will soon go decades without seeing a hyperactive season like 1995, 2004, 2005, 2010, or 2017?

[MarioProtVI]

In my opinion, I think the current +AMO will last for another decade or so before we flip to -AMO. The peak of +AMO is likely going to be sometime in the 2020s (a study from a while back I think said 2020 could be the peak based on the previous patterns). I think it will be a gradual flip sort of similar to 1964-71, where the amount of above average seasons in terms of quality and quantity begin to decrease in frequency with one final big burst (of one or two above average seasons) before falling into a cool phase, probably by 2030 to 2032, when taking into account previous +AMO cycle durations. In fact you could argue 1971 was the start of the last -AMO given 1970 seems to have gotten quite a boost in preliminary reanalysis (remember that endless TD? Yeah that was actually a hurricane in the subtropics near the Azores so shows how better technology we have now)

However I do think the next -AMO period will be different due to the improvement in technology and ability to detect small, short-lived and high latitude tropical/subtropical cyclones, which will up the average named storm count a bit. I think seasons like 2018 (which had an -AMO look to it but ended up above average) but a bit less active will be the norm in the next -AMO, with stronger subtropics and weaker MDR. Caribbean probably not as favourable.

My final guess as to the average during -AMO would probably be 10-4-1, given the differences in technology from the last such period.

[AveryTheComrade]

I believe the AMO will flip again next decade, probably around the middle 2030s. However, with global warming i assume -AMO will be significantly more mild, perhaps similar to 2013's SSTs (obviously more favourable otherwise). So no, I don't believe that we will enter pre-1995 levels of activity again, I expect the average to go up for 2 decades with 1991 - 2020 climatology and 2001 - 2030 climatology and then steadily decrease to near where it is now with 1981 - 2010. I think the average will look something like 14-6-3, especially since we now have better techniques to identify small subtropics systems. 2018 seems like the best analog for what the next -AMO might look like.

[EquusStorm]

It's going to be interesting seeing the 1982 and 1983-esque seasons with modern technology when we switch over to -AMO; probably will have a few more storms classified in the subtropics (my own peering at old satellite imagery certainly suggests 1983 had other brief high latitude systems) but many fits of boredom and frustration on forums haha.

The fact that destructive seasons like 1979, 1985, 1988, and 1989 (and active years like 1990) happened in the last -AMO makes me think there probably won't be much of a lack of dangerous hurricanes though - just fewer per season - and we might not even notice too much for except for lower average ACE and no truly hyper seasons.