Changes in Tropical Cyclone Intensity & Track

[Don C L]

Sailorboy1, for what its worth I think your question is certainly a valid one. But I think when you look at the research it demonstrates that our ability to measure, though improving all the time, has been adequate to make the call for many years now.

[GordMay]

Extreme Hurricane Rainfall, in the Caribbean, Five Times More Likely

A study [1], led by the University of Bristol, analysed future projections of hurricane rainfall, in the Caribbean, and found it to be particularly vulnerable to climate change, resulting in extreme hurricane rainfall events being as much as five times more likely, in a warmer world.

Due to a combination of increased stalling, and precipitation yield, under a warmer world, their analysis [1] indicates a greater likelihood of extreme hurricane rainfall, occurring in the Caribbean, under both Paris Agreement scenarios of 1.5 ∘C, and 2 ∘C Global Warming goals, compared to present climate projections.
Focusing on specific hurricane events, they show that a rainfall event, equal in magnitude to Hurricane Maria, is around half as likely to occur, under the 1.5°C Paris Agreement goal, compared to a 2°C warmer climate.

Hurricane Maria brought, as much as, a quarter of normal annual rainfall, to some regions of Puerto Rico, when it made landfall, in 2017, and storms of this magnitude are roughly once in a 100-year events.
The results show that in a 2°C warmer world, an event of similar size, to Maria, would be more than twice (2.3 times) as likely, occurring once every 43 years.
Similarly, a 100-year storm, affecting the Bahamas, would be 4.5 times as likely, under the 2°C Paris Agreement scenario, compared to the present day.
Under the more ambitious goal of 1.5°C warming, such extreme hurricane rainfall events, affecting the Dominican Republic, would occur roughly once every 57 years, which is half as likely, compared to the 2°C warming scenario, where they would occur once every 30 years.

[1] “Extreme hurricane rainfall affecting the Caribbean mitigated by the paris agreement goals” ~ by E L Vosper et al

”... Due to a combination of increased stalling and precipitation yield under a warmer world, our analysis indicates a greater likelihood of extreme hurricane rainfall occurring in the Caribbean under both Paris Agreement scenarios of 1.5°C and 2°C Global Warming goals, compared to present climate projections. Focusing on specific hurricane events, we show that a rainfall event equal in magnitude to Hurricane Maria is around half as likely to occur under the 1.5°C Paris Agreement goal compared to a 2 ∘C warmer climate ...”

Open Access ➥ https://iopscience.iop.org/article/1...48-9326/ab9794

[Hasbeen]

Until they get a handle on the effect of clouds, & include this in any models the whole thing is more scam than science. Not one prediction from these models has been correct, or even close.

[GordMay]

Originally Posted by Hasbeen

Until they get a handle on the effect of clouds, & include this in any models the whole thing is more scam than science. Not one prediction from these models has been correct, or even close.

Climate models ARE, increasingly, including the effect of clouds, in their analysis.
If you think that earlier climate predictions have not been born out, in current observations [were wrong]; you’ve not been paying attention.

The impact of clouds, on global temperature, is a complex area of research, that scientists have been working on for decades.

Clouds have long been one of the biggest uncertainties, in climate calculations. They can both shade the Earth, and trap heat.
Which effect dominates, depends on how reflective they are, how high they are, and whether it is day or night.

Things are made more complicated, because cloud dynamics are complex, and happen on small scales, that are hard to include in the models, used to predict future climate.
Atmospheric scientists have been aware, for at least two decades, that the complex effects of clouds, on radiation, and water exchanges, pose a major challenge to the understanding of climatic change.

Recent comparisons of the predictions, made by various computer climate models, show that the problem has not gone away. In some models, for instance, clouds decrease the net greenhouse effect, whereas in others they intensify it.

Most newer climate models show more future warming, than previous ones; and it may be due to how they incorporate clouds.
A review paper [1] suggests that clouds, and the tiny particles that help them form in the atmosphere, have something to do with it.

The quest for more data about clouds, and climate, continues, in parallel with the refinement of climate models. It is a slow-going process: each new piece of information must be incorporated throughout. With certain findings, the models themselves may have to be reformulated.
But the result should be an increasingly precise understanding of how sensitive the clouds are, in response to changes in external forces, and what effect those changes would have on global warming. One must hope that the model building, and data collection activities, will lead to an improved understanding of climatic change.

“Why Clouds Are the Key to New Troubling Projections on Warming” by Fred Pearce
“The debate about clouds and climate change is part of a larger concern about feedbacks in warming the world”
➥ https://e360.yale.edu/features/why-c...ons-on-warming

[1] “Context for interpreting equilibrium climate sensitivity and transient climate response from the CMIP6 Earth system models” ~ by Gerald A. Meehl et al
➥ https://www.science.org/doi/10.1126/sciadv.aba1981

[GordMay]

Originally Posted by Hasbeen

... Not one prediction from these models has been correct, or even close.

An evaluation of global climate models [1], published between 1970 and 2007, used to project Earth’s future global average surface temperatures, over the past half-century, concludes: most of the models have been quite accurate.

The results: 10 of the model projections [of 17 evaluated] closely matched observations. Moreover, after accounting for differences between modeled and actual changes in atmospheric carbon dioxide and other factors that drive climate, the number increased to 14. The authors found no evidence that the climate models evaluated either systematically overestimated or underestimated warming over the period of their projections.
The authors say that while the relative simplicity of the models analyzed makes their climate projections functionally obsolete, they can still be useful for verifying methods used to evaluate current state-of-the-art climate models, such as those to be used in the United Nations’ Intergovernmental Panel on Climate Change Sixth Assessment Report.

Even Exxon got it right, as early as 1977.[2]

[1] “Evaluating the Performance of Past Climate Model Projections" ~ by Zeke Hausfather et al
➥ https://agupubs.onlinelibrary.wiley....9/2019GL085378

[2] “Exxon disputed climate findings for years. Its scientists knew better”
➥ https://news.harvard.edu/gazette/sto...limate-change/

[Ryban]

Another thread primed for being locked-down.

[Bycrick]

As well it should be. When a thread reaches the point of "You’re ignorant if you don’t agree with me," it’s time to shut it down.

[Ryban]

Originally Posted by Bycrick

As well it should be. When a thread reaches the point of "You’re ignorant if you don’t agree with me," it’s time to shut it down.

The thread should also have stayed on topic and focused on the science and the forecasting, papers, reports, and models, rather than the lay-person's opinions about such.

[Bycrick]

The "science" is meaningless by itself. The ultimate question is deciding what we are going to do in response to the "science." So even if one is willing to agree that the climate is changing, that doesn’t imply that they have to adopt a particular set of political solutions.

[chrisr]

is anyone aware of a study or information concerning likely trends for TRS in the south pacific region ?

specifically french polynesia

historically this area is almost immune to TRS, but with climate change etc how this is likely to change is keeping me awake at night

cheers,

[GordMay]

As the climate continues to warm, hurricanes may intensify more rapidly, just before striking land, making hurricane forecasting more difficult.
Kerry Emanuel’s study [1] of hurricanes found that it may be harder to predict hurricane intensity, in a warmer world. The reason is that, a hurricane can weaken, or strengthen, more rapidly than before, and things that change quickly are inherently hard to predict.

On the other hand, winter storms, like the thunderheads that roll across the American Midwest, might grow more predictable, as climate change makes them unfold more slowly.

[1] “WILL GLOBAL WARMING MAKE HURRICANE FORECASTING
MORE DIFFICULT?” ~ by Kerry Emanuel

"...
Forecasting unusually rapid intensification of hurricanes is particularly problematic.
A recent case in point is Hurricane Patricia, which affected the eastern North Pacific in 2015.
During a 24-h period from 0600 UTC 22 October to 0600 UTC 23 October Patricia intensified by an astonishing 105 (kt; 1 kt = 0.51 m s–1), from a 75-kt category 1 storm to a
180-kt category 5 storm (Landsea and Franklin 2013;
NHC 2016).
During this same period, the National Hurricane Center (NHC) predicted an intensification by only 30 kt.
Had the storm made landfall at the end of this period of rapid intensification, the result could have been catastrophic given the poor anticipation of the magnitude of the event.
...

➥ https://texmex.mit.edu/pub/emanuel/P..._BAMS_2017.pdf

[Bycrick]

Things that change are hard to predict. Hmmmmm. That means it’s hard to predict climate change, no matter how many models people gin up.

[GordMay]

Originally Posted by chrisr

is anyone aware of a study or information concerning likely trends for TRS in the south pacific region ?
specifically french polynesia ...

Not FP, but FWIW:
“Tropical cyclone climatology, variability, and trends in the Tonga region, Southwest Pacific” ~ by Moleni Tu'uholoaki et al

”... No significant long-term trends were found in the number of TCs, severe TCs, and accumulated cyclone energy (ACE) over the period of study...”

➥ https://www.sciencedirect.com/scienc...639?via%3Dihub

[GordMay]

“Cyclones in French Polynesia”
➥ https://www.bwsailing.com/cyclones-in-french-polynesia/

“French Polynesia Cyclone outlook”
➥ https://www.sailsouthpacific.com/new...clone-outlook/

[BG305]

I really don’t see what all the fuss is about with climate change, unless it’s supposed to be linear and not change.