[ApolloFortyNine]

Harvey was the first cat3+ hurricane to hit the US in 12 years.

Your comment is already grey, I just wanted you to know why.

EDIT: Could I not get downvoted for stating a fact. That'd be great. I guess it was actually only 11 years and 10 months, is that the problem here?

[todayiamme]

And that's pretty pointless, because it is clear that while there is seasonable variation in the frequency of occurrence of storms; the shift in the frequency of intensity is a phenomena that's a global event happening at scale. The global weather system goes through a series of cold and warm cycles, but the mean has been shifting for a while that has had a global shift in the frequencies of different storm strengths being seen around the world;

Here's a graph demonstrating this phenomena; https://imgur.com/a/97x7d

I've taken this from this study; https://www.researchgate.net/profile/Chih_Yuan_Yang/publicat...

That arrives at this conclusion,

> However, storm frequencies during the current warm phase (since 1995) have also been much higher than during the previous warm phases in the middle of the last century. The difference can no longer be explained by natural fluctuation; rather, this difference must be attributed to global warming.

After making this rather thorough argument (reproduced here in its entirety because it is important to pay attention to the nuances of the science);

> In addition, for climate variables, recent studies (e.g. Lehmiller et al. 1997; Bove et al. 1998; Maloney and Hartmann 2000; Elsner, Jagger, and Niu 2000; Goldenberg et al. 2001; Landsea 2005; Sutton and Hodson 2005) have attributed Atlantic hurricane activity increases to a natural climate cycle, termed the Atlantic Multidecadal Oscillation (AMO), the El Nino-Southern Oscillation (ENSO), and the North Atlantic Oscillation (NAO). In recent decades, Geo Risks Research has undertaken hurricane frequency analyses that account for the AMO. The AMO index is a detrended (anomaly) measure of sea surface temperatures (SSTs) (e.g. Knight et al. 2005) and is believed to be capable of explaining the recently elevated levels of hurricane activity. Because it is a measure of SST anomalies, which are correlated with hurricane activity, the AMO index has been used to predict near-term hurricane activity. Therefore, warm phases in the AMO (positive AMO index) are theorized to lead to higher SSTs and above long-term average hurricane activity in the Atlantic. Conversely, cool phases in the AMO (negative AMO index) are theorized to lead to lower SSTs and below long-term average hurricane activity.

> One of the most important recent papers on this topic is the article by Elsner et al. (2008), who consider a time-series model to forecast the average hurricane-season Atlantic SST and then use a linear Poisson regression model to forecast North Atlantic hurricane intensity given the predicted coefficients of the Atlantic SST model.

> However, some studies (Knutson and Tuleya 2004; Barnett et al. 2005; Emanuel 2005; Webster et al. 2005, 2006) indicate that global climate change (rather than natural climate cycles) may play the dominant role. In addition, the fourth status report of the Intergovernmental Panel on Climate Change (IPCC 2007) highlights the significant link between human-induced global warming and the greater frequency and intensity of unanticipated tropical cyclone events.

> Figure 1 clearly shows that the average number of destructive major hurricanes is significantly higher in the warm phases of the AMO than in the cold phases. This finding supports the theory that hurricanes form over warm sea surfaces. However, storm frequencies during the current warm phase (since 1995) have also been much higher than during the previous warm phases in the middle of the last century. The difference can no longer be explained by natural fluctuation; rather, this difference must be attributed to global warming. Based on these U.S. Hurricane Risk Measurement 3 opinions, the modeling of hurricane activity should have the ability to additionally capture the time trend of hurricane activity to illustrate the phenomenon that hurricane activity increases with time because of global warming.

Texas isn't the only place on Earth where this phenomena is playing out. And you may downvote me, but that doesn't change the data nor the facts.

[ApolloFortyNine]

At the beginning of your post, you mention the 12 year gap as a result of seasonal variation between cold and warm cycles. Then your source points out that the current warm phase has been going on since 1995.

This is a waste of time.

[todayiamme]

I don't understand the point you're making. Also to be clear, your statement;

> Harvey was the first cat3+ hurricane to hit the US in 12 years.

is patently false, because in that time period we've had (and I'm including 2005);

Katrina Cat. 5 (2005)

Rita (2005)

Wilma (2005)

Ike Cat. 4 (2008)

Sandy Cat. 3 at peak (2012)

I didn't bother to correct you earlier, because Cat. 3+ hurricanes hitting the US are more or less a very narrow set of data points. When you view the system globally and at sea, start counting the total number of hurricanes, and add up the data, then the trend becomes quite clear.

I feel that such cherry picking doesn't befit our discussion. Because we can argue passionately over this and one of us might convince someone else that we're right, but at the end of the day - either way - nature can't be fooled. Nature can't be lobbied against. Nature doesn't care about PR firms. Nature can't be reasoned against. Nor can the law of thermodynamics.

We have put a large amount of energy into the global system. We can now argue with the laws of man whether this is reasonable or not, but we can't argue against the laws of thermodynamics.

The data is clear. There's something going on and the mean frequency of intensity has increased. And we have a relatively solid understanding of why this has happened - which can be wrong, but the balance of probabilities right now is that our theory is correct. You can call BS all you want, but that doesn't change the science. That doesn't change the facts at hand.

[jtuente]

He specifically mentioned hitting the US. Ike hit Texas as a Cat 2 storm, Sandy hit the east coast as a Cat 2 storm. Their peaks (4, 3) were out in ocean/sea waters near the island nations. Of course, you don't have listen to me or the weather people who repeatedly say that storms have not increased in frequency or intensity (beyond their normal cycles) [0].

[0] - https://twitter.com/RyanMaue/status/908030951975989261

[todayiamme]

Have I made the claim that it increases the frequency of occurrence? I feel that link is a red herring and obfuscates reality. What I, and all of the papers above, have been referring to is the frequency of intensity of storms. NOT the frequency of storms.

Other than the graphs I've already pasted, the phenomena shows up over and over again in the power dissipation index;

http://images.nature.com/m685/nature-assets/ngeo/journal/v3/...

Here's yet another paper on the topic and its graphs;

http://rsta.royalsocietypublishing.org/content/roypta/365/18...

http://rsta.royalsocietypublishing.org/content/365/1860/2695

> Of course, you don't have listen to me or the weather people who repeatedly say that storms have not increased in frequency or intensity (beyond their normal cycles) [0].

First of all, the graph you linked to only mentions the frequency of occurrence. It does not include intensity. Second, I trust well sourced papers featuring replicable research by scientists published in notable peer-reviewed journals over random people on Twitter.