05-26-2026, 02:44 PM
(This post was last modified: 05-26-2026, 02:46 PM by Durian Fiend.)
Regarding the future of our tank filling trade wind showers in a changing climate, this presentation by Harry Durgin back in December of 2025 could be of interest.
https://www.facebook.com/groups/PunaWeat...058490362/
He sums it all up in the first 7 minutes. The comparisons are for the time period 1945-1964 with 2005-2024. I was surprised to hear that the frequency of trades has actually increased for the Hilo area. 5 factors are considered important for trade generated rainfall: How often trades blow, how strong they are, how much moisture is in the air, subsidence (air rising or falling) and the inversion height. The trend for Hilo: More often, a little stronger, a bit less moisture, more subsidence and lower inversion height. Resulting in, he says, essentially no change in rainfall. (so far).
Hmm. I thought there had been a slight decrease? Perhaps it's the other sources of rainfall that are responsible for the drop off.
The study also looked at Lihue and they have trended noticeably drier, primary reason being that their mountains are lower.
https://www.facebook.com/groups/PunaWeat...058490362/
He sums it all up in the first 7 minutes. The comparisons are for the time period 1945-1964 with 2005-2024. I was surprised to hear that the frequency of trades has actually increased for the Hilo area. 5 factors are considered important for trade generated rainfall: How often trades blow, how strong they are, how much moisture is in the air, subsidence (air rising or falling) and the inversion height. The trend for Hilo: More often, a little stronger, a bit less moisture, more subsidence and lower inversion height. Resulting in, he says, essentially no change in rainfall. (so far).
Hmm. I thought there had been a slight decrease? Perhaps it's the other sources of rainfall that are responsible for the drop off.
The study also looked at Lihue and they have trended noticeably drier, primary reason being that their mountains are lower.