2025 Atlantic Hurricane Season

[BarryStantonGBP]

a bit too low on the numbers

https://www.cyclonicfury.com/2025/04/01/2025atloutlookapr/

[Stormchaserchuck1]

ENSO subsurface continues to be cold in the central region, which at the very least favors ENSO Neutral this season. Last year I did research on the trend regarding different Hurricane season factors. Here's how ENSO subsurface has been leading surface events:

Here's my post from last year which is a 1 year old, but you can still see the long term trends.. I think we had 18 Named Storms last year, 11 Hurricanes. 

In 1995, the AMO (Atlantic Multi-decadal Oscillation) index switched to positive, and since then it's been rising/still hasn't peaked. 

Atlantic Hurricane season activity is strongly correlated to the AMO, and Atlantic Hurricane season activity has also been in an upward incline since the 1995 AMO switch. Here is a smoothed graph of number of Tropical Storms by year: 

Since 1995, we have averaged the following number of storms per year in various ENSO states:

El Nino (8 years): 12.5 TS, 5.4 Hurr, 2.5 MH

Neutral (10 years): 16.4 TS, 8.2 Hurr, 3.8 MH

La Nina (10 years): 17.9 TS, 9.2 Hurr, 4.2 MH

In September 2022, the AMO peaked at an all time high of +0.662, and is still rising/in an inclining phase. I plotted monthly AMO numbers, up until the CPC last updated the dataset, which was January 2023:  

If you smooth out the index, it looks like a very clear rising phase is still underway: 

Since those AMO graphs, we had record +AMO last Summer, now it's cooled down to be cooler than the last 2 seasons, but still above the 30-year average. We are still on the general AMO trends. 

The Atlantic activity has been especially strong lately:

- 4 of the last 5 years have had 18+ Named Storms

- The average in the last 5 years is 20.5 Named Storms/year 

- 8 of the last 9 years have had 7+ Hurricanes

- The average is 8.7 Hurricanes/year for the last 9 years

With ENSO Neutral and slightly warm Atlantic SSTs, I'd put the over/under on this season at ~16-17 Named Storms, just based on long term trends. Remember, the rest of the globe has not been nearly as active as the Atlantic.