Charles Rotter
On October 9th, as Hurricane Isaias closed on the coast, Climate Central put out an analysis saying human-caused warming had heated the water under the storm and added about 7 mph to its winds. That same day, a reader asked Chris Martz about a claim attributed to Al Roker, that Isaias was fueled by a Gulf running 5 to 6 degrees above normal. I was unable to find the claim online. It probably occurred during a segment.
Chris, a friend of WUWT, answered with data. His post follows, with a few notes from me.
Al Roker is not an actual meteorologist.
But I am.
You ask a really good question. And while Roker has opinions, I have data.
Yes, it is true that tropical cyclones (TCs) operate as thermodynamic heat engines sustained by ocean-to-atmosphere enthalpy fluxes, including sensible and latent heat transfer, with latent heat released during condensation, which maintain the deep convection. The higher the sea surface temperatures (SSTs) are, the higher the likelihood for TC intensification.
However, SST anomalies represent departures from climatological averages rather than absolute SSTs. That means below-average SSTs can still support an intense hurricane. In fact, the Gulf of Mexico (or Gulf of America; call it whatever you want) is warm enough during late August, September, and early October every year to support a hurricane of category four or five strength. That has always been the case and it always will be.
https://x.com/ChrisMartzWX/status/2108781894368137294?s=20
That’s the whole argument in one paragraph. An anomaly is a departure from average. It isn’t the temperature, and the Gulf in September is never short of fuel.
I hypothesized that Gulf SSTAs don’t really affect TC strength as commonly claimed because of this fact. So, I decided to investigate this question to provide a numerical answer. All science is numbers.
For this analysis, I decided to use the NOAA National Hurricane Center’s (NHC) HURDAT2 database, which contains historical TC tracks (coordinates), maximum sustained wind speeds (Vmax), and pressures, which contains data spanning 1851 to 2025. I then employed the Extended Reconstructed Sea Surface Temperature (ERSSTv5) dataset from NOAA, which contains monthly SST estimates on a 2° × 2° grid since January 1854. So, my analysis must be restricted from 1854 to 2025.
I identified 269 TCs that attained hurricane strength (≥64 kt / ≥74 mph) within the Gulf during the study period. Of this subset, 70 originated within the Gulf itself, while the remaining 199 developed elsewhere, primarily in the Atlantic or the Caribbean Sea, before entering the Gulf. For each hurricane, I determined its highest Vmax while inside the Gulf specifically. I then compared that intensity against the mean SSTA (calculated by evaluating SST departures from the 1991–2020 baseline) sampled along its Gulf track, using the monthly ERSSTv5 data.
Monthly SST data is not perfect, but it provides us a fairly good estimate because water has a high heat capacity, meaning it takes a lot of energy gain in order to warm a body of water and a lot of energy loss to cool it. In layman terms, SSTs are usually rather slow to change from week-to-week.
https://x.com/ChrisMartzWX/status/2108781894368137294?s=20
Both datasets are NOAA’s and both are public. Available to everyone.
The results show essentially no linear relationship between Gulf SST anomalies and the maximum sustained wind speeds attained by hurricanes within the basin.
Across all 269 Gulf hurricanes, the Pearson correlation coefficient was just r = +0.036, which indicates an extremely weak positive correlation. The coefficient of determination (R²) was 0.001, meaning that variations in SST anomalies explained approximately 0.1% of the observed variation in peak hurricane intensity under a simple linear regression model. The Spearman rank correlation coefficient was similarly negligible at ρ = +0.012. Furthermore, the Pearson correlation yielded a p-value of 0.555, well above the conventional statistical significance threshold of 0.05.
Therefore, the observed relationship is not statistically significant.
https://x.com/ChrisMartzWX/status/2108781894368137294?s=20
An R² of 0.001. Departures from normal account for about a tenth of one percent of how strong Gulf hurricanes get.
The scatterplot below illustrates this quite clearly. Hurricanes attaining relatively modest maximum intensities of 65–85 kt occurred across a broad range of SSTAs, as did much stronger hurricanes exceeding 100–120 kt. Some of the most intense hurricanes in the dataset occurred during periods when SSTs along their Gulf tracks were below the 1991–2020 average. Conversely, some hurricanes traversing anomalously warm waters never intensified beyond minimal hurricane strength.
In layman terms? An anomalously warm Gulf has no meaningful correlation to Gulf hurricane intensity.
https://x.com/ChrisMartzWX/status/2108781894368137294?s=20
The story you just read is true. Only the name of the Gulf has been changed.
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h/t Chris Martz, @ChrisMartzWX.
Climate Central’s analysis as carried by WSMV: https://www.wsmv.com/2026/10/09/warmer-gulf-waters-may-have-fueled-hurricane-isaias-analysis-finds/
No hurricanes all summer and now that we have one, “climate change made it worse”
is invoked. Is there anything in this world that is more predictable?
“Is there anything in this world that is more predictable?”
Yes, claiming that everything is racist. In fact, your comment is racist. 😉
The refuser troll crowd is aghast, and will be here shortly with charts showing more and more severe hurricanes, just as predicted by CliSci. Except Mr. Nail, who says they never said it at all.
That was way back in a post highlighting the lack of any North Atlantic hurricanes at all up that point, right? Comes at you fast.
Regarding the “more and more severe hurricanes” nonsense; as has been pointed out numerous times, the IPCC forecast is for no increase and possibly even a reduction in the frequency of Atlantic hurricanes with increasing temperatures. Of those hurricanes that do occur, however, a higher proportion are expected to reach ‘major’ status. It’s that simple.
When I asked for a scientific source for the claim that there would be “more and more severe hurricanes” I was met with a few obscure newspaper clippings or references to blogs.
“Of those hurricanes that do occur, however, a higher proportion are expected to reach ‘major’ status. It’s that simple.”
Simple, huh? A few % might be stronger? And you think that’s solid, irrefutable, settled science? Is it falsifiable?
Mr. Nail: Well, the first post about that (9/29, linked in the second post where you commented) showed his work about past CliSci predictions. Now I see that your basis for saying it was never predicted is ….ta da! this year’s IPCC prediction. Only this year!! No other IPCC docs to be considered??!! No other Al Gore post-Katrina climate predictions (Gore always claims to speak for clisci)?
You sure got a lotta mileage from your little head-fake.
What is the proportion of one (1) that will be more severe? A common rule of thumb is that one needs 20-30 samples for statistical significance. Many of us here don’t have 20-30 years of life left to accumulate that number of samples. We will go to our graves not knowing who was right. It sounds like a safe bet that is unlikely to be proven wrong in our lifetimes. The only thing safer is a ‘sucker bet,’ such as “Heads I win, tails you lose.”
Nice analysis.
According to NASA, NOAA, and Climate Central, hurricanes are getting more intense because global warming is warming ocean surface waters. Except like so many other global warming claims from those vested interest entities, it simply isn’t true.
Shown here by analysis of the Gulf (of whatever) since 1854.
Shown for the entire Atlantic basin by ACE since 1950.
And according to NHC, hurricane intensification is the least understood and least predictable of the TC variables they expertly monitor. Stuff like overall diameter and eye wall replacement are involved. Take Katrina. Came off the Atlantic near Fort Lauderdale as a cat 1, then intensified to a cat 5 over the Gulf after completely crossing Florida as just a weaker tropical storm, before finally hitting New Orleans as a cat 3.
Climate central–“The analysis also found that the unusually warm water where the storm first developed was made up to 800 times more likely.
While the 88-degree-plus waters along the path were 4 to 600 times more likely because of changing weather patterns over the years.”
Yes, in following I noticed that Gulf SST temperatures seemed a little high, but still have a long poorly understood question about the heat budget below the ‘adequate amounts (?)’ measured of a severely activated surface. I’ve seen, even measured, and read enough about up, side, and down-wellings where T changes more than a few degrees. Since we now have airplanes for the atmosphere it might be at least interesting to see what submarines or the newer aquatic robots could measure.
I’m up to 600 feet tall and yet I can’t dunk a baskatball. WTF!!??!?
Let’s grant for the sake of argument, that the increase of CO2 molecules in the atmosphere has led to a small increase in the Earth’s temperature.
Any such effect that would increase the temperature of the Earth’s atmosphere, may then increase the temperature of the oceans as a second-order effect.
We do know for a fact that tropical cyclones operate as thermodynamic heat engines.
Therefore, I cannot conceive of any model where “warming” the cold sink side of the engine more than warming the heat source side, can possibly result in MORE work being performed by the heat engine.
It seems to me that warming of the atmosphere (by any mechanism) should tend to weaken tropical cyclones (assuming that mechanism is not warming the oceans by a greater amount).
Nice simple general thermodynamic explanation for the observed facts. Kudos.
Space, and by extension the upper atmosphere, will always remain cold. Greater surface warming enhances convection. All of that is fine, but it would seem that there should be some hard limits. There’s only so much heat that can build up at lower levels before it must rise/spread out/dissipate etc.
I heard FungalNail and his cronies were working on rewriting the Laws of Thermodynamics by proving that a blow dryer is the best tool for heating bath water. Sadly, some neglected to step out of the tub first; their results were quite shocking!
Yup. Basic logic and reason is counter to the Eco-Nazi nonsense. Ditto for “more extreme” weather in general. Because of the way the Earth warms (tropics basically unchanged, most of the increase in the “average” temperature occurs in the high latitudes and the poles – AND is mostly nighttime low temperatures not getting as cold, NOT high temperatures getting “hotter), we should expect LESS “extreme weather,” NOT more.
And a recent Atlantic Ocean sediment study showed tropical cyclone activity was higher DURING THE LITTLE ICE AGE than it is today.
On the other hand another meteorologist (Jeff Masters) has posted this ….
https://www.theinvadingsea.com/2026/04/28/hurricane-intensification-global-warming-climate-category-5-atlantic-florida-helene-wind-speeds/
Comments like this: “ Statements like this are often used by climate deniers to downplay climate change risks.” in this article pretty much removes all credibility.
Jeff Masters of Yale Climate Connections. He cites six dubious studies despite having first stated under his first topic heading “SPOTTY DATA”,
“The relatively poor quality and short length…make scientific statements on how climate change is affecting hurricanes difficult.”
As in the Japanese saying totemo muzukashii, or ‘VERY difficult’, by which is meant impossible.
Yale Climate Connections, hey?
Boy, are they powerful!
Their role in our lives is as follows (apparently) –
“We are not here to tell you what to do.
Instead, we’re here to present you with knowledge that you can use to take control of your future.”
(My response to their ‘mandate’ – f*ck off!)
Populare GMST data, UAH et. al., are anomalies not actual temperatures.
Anomalous trends and spikes are much more useful for scaring the goobers.
Anomalies are necessary and useful for global temperature trends, because they wash out the to be expected locational differences in actual temperature by latitude and altitude.
But they are also very deceptive when they wash out real differences in GAST (~ +/-3C) between the various climate model tuned 30 year hindcasts, as the CMIP does to pretend the models are all in ‘sync’ when even after tuning they are obviously not. The hindcast 30 year real temperature difference is about 2x the to 2100 model forecast rise.
“Anomalies are necessary and useful for global temperature trends”
The problem is that temperature anomalies don’t predict climate change! The Great Plains savannah and the Central Africa savannah are both the same basic climate yet have big differences in temperature. It doesn’t really matter if the anomaly in Kansas is +.01C and in Africa is + .01C – neither climate is going to change!
It’s the variance in the absolute temperatures and the precipitation that determines climate. Climate science should be looking at temperature VARIANCE, and not at temperature anomalies.
(does a change from -9C to -8C in the Arctic *really* indicate a change in the Arctic frozen climate?)
The anomalies method on an active environment are illogical. That is, the controlling factors such as the location of cloud coverage, and the that the ocean heat moves, really tells us nothing of importance.
Anomalies are only really relevant on a static system.
With the anomaly system on an active system, it takes a disproportional reduction of heat to bring the average temperature down.
As an example, the two high anomalies in Jan and Feb 2016, were both in the far north in Russia, near the coast of the Arctic. The wind changed for a few days and the temperature rose from -27 to – 20.
The wind changed for a few days, it came from the south west bringing warm air instead of cold air from the north west.
Have a look at the UAH chart above.
And then there is the urban heat island effect etc etc.
The anomaly process is very misleading.
With all due respect, the “scientists” should know better.
“The wind changed for a few days and the temperature rose from -27 to – 20.”
Yeah, that’s *really* going to change the climate there! <sarc>
Anomalies aren’t very useful by themselves in predicting whether, or to what extent, the southern oceans will freeze.
You should also note that, while anomalies may have some value, the collection of models cannot come close to agreeing on the actual average global temperature. Model disagreement in actual temperature estimates rivals the magnitude of the alleged anomalies.
Wait! Is that a Postal Inspector outside your window?? No! Don’t look!
Very nice, the other side is full of scat.
As regular visitors to this site have noticed, the climate alarmists will use the slightest departure from normal weather occurrences and attribute them to man-made global warming that triggers some sort of violent storm, flood, heat wave, cold snap, etc.—you name it. Except in this case, among others, hurricane activity is to be expected in this particular region of the US. They conveniently omit any mention the fact that such activity has been below normal thus far this year. So what’s the big deal?
“departure from normal weather occurrences “
Bold is from me.
Need I say more?
Climate Crazies, ” We don’t need no stinkin’ evidence”.
What a fantastic revealing report. This what you really call AI. Anthropological Information.
The most important element that initiates and causes Hurricanes / Tropical cyclones to form, and then to accelerate progressively or rapidly, IS NOT KNOWN.
As Dr Judith Curry stated in 2016, there has been no further improvement or understanding of hurricanes for over 20 years.
Now its over 30 years.
Thank you Charles for bringing this article by Chris Martz to our attention.
“In layman terms? An anomalously warm Gulf has no meaningful correlation to Gulf hurricane intensity.”
Someone needs to get out and meet more laymen.
This egg macmuffin is anomalously warm and has no meaningful correlation to ketchup packets? Maybe I’m underestimating the US education system.
Still looking for any of the Gulf weather stations that reported hurricane strength winds. I would be very grateful for a pointer as none of those I was logging reported anything over 61KtsG70kts