Jim Steele
Hurricane Beryl intensified dramatically, strengthening from a tropical depression to a major hurricane in just 42 hours. How could the ocean so rapidly provide enough heat to increase a hurricane’s intensity over such a short time period of time, while travelling northward into cooler sea surface waters?
Hurricane intensification is controlled by 3 dynamics. 1) Energy supplied by sea surface temperatures; 2) Wind shear that increases during El Nino and ENSO neutral years and disrupts the storm structure needed to become a strong hurricane; 3) Ocean Barrier Layers that prevent the storm from sucking up colder subsurface waters that usually prevents intensification, as well as creating a layer of warmer than normal subsurface water that supplies the extra heat needed to intensify the storms.
Barrier Layers are key for understanding intensification, but rarely accounted for in media fearmongering. Hurricanes intensify when sub-surface Barrier Layers form and block the hurricanes from naturally pulling up cold subsurface water which prevents further intensification. Barrier layers block the upward suction of cold water, as well as providing the extra stored heat that increases intensification.
Barrier Layers form when fresh-water overlays warmer saltier water preventing convection that ventilates subsurface heat and causes subsurface heat to accumulate. In the Caribbean, Barrier Layers commonly form when the freshwater plumes from the Amazon and Orinoco Rivers flow northward into the Caribbean. Those river discharges peak in June, so Beryl’s intensification off the Venezuelan coast in June is not unusual!
Barrier layer formation is patchy based on the coincidence of freshwater flows overlaying warm ocean currents. Barrier layers are short-lived. Thicker barrier layers last 30+ days and thinner ones survive less. Different patterns of the local patchiness of barrier layers are why we see hurricanes intensify in one location along their storm track but only for a short amount of time, a day or less. The thicker the Barrier Layer the greater the storm intensification, and the greater duration of a strong hurricane.
Beryl will likely decrease in intensity after Tuesday July 2, 2024 as it moves northward outpacing the thicker transport of the barrier layer along the Venezuelan coast. These barrier layer dynamics are just now being more frequently studied, so their effects are seldom discussed, never mind presented in fearmongering media. However read https://news.miami.edu/stories/2018/09/how-does-a-river-plume-influence-hurricanes-in-the-caribbean.html
Ma (2023) “Interannual Variability of Barrier Layer in the Tropical Atlantic and Its Relationship with the Tropical Atlantic Modes” provides a good analysis of Barrier Layers.
Ma wrote, “Since the importance of the Barrier Layer has been revealed, many studies have discussed its formation mechanism in the Atlantic Ocean using observational data. Masson and Delecluse (2001) found that in boreal winter and spring, freshwater from the Amazon River flows through the surface along the northern coast of South America, resulting in a thicker BL in this region.”
As Ma (2023) illustrates, the plume of freshwater that enables that Barrier Layer to develop gradually moves northward into the Gulf of Mexico. The BLT (Barrier Layer Thickness) off the coast of Venezuela where Beryl has just intensified is greatest in winter and spring, then thins as summer progresses and is the thinnest in September-November.
I would predict that Hurricane Beryl will now rapidly weaken as it outpaces the northward movement of the Barrier Layer which supplied the required heat for intensification to a category 4 & 5 hurricane. It is pure randomness that allows a tropical storm’s track to coincide with a thick Barrier Layer, that caused Beryl’s rapid intensification. However, to observe a similar one or two-day period of hurricane intensification was highly unlikely before that age of satellites in the late 1970s, and we will never know how unusual Hurricane Beryl really is historically.
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The legacy media prefers the wrath of CO2 as an explanation for hurricanes.
Unfortunately Cat
53 Beryl is only Cat 3 with winds measured at 6,500-8,000′ AGL, where such winds do no damage. At the surface (10M) Beryl is only a fairly strong Cat 1 with sustained winds of 81mph. According to Ventusky https://www.ventusky.com/?p=17.197;-75.131;10&l=wind-10m&w=offEven Earth.Nullschool.net shows sustained surface winds of 74mph https://earth.nullschool.net/#current/wind/surface/level/orthographic=-75.08,17.41,2304/loc=-75.507,17.504
GOES EAST satellite imagery shows the eye wall vanishing as the storm approaches Jamaica https://www.star.nesdis.noaa.gov/goes/sector_band.php?sat=G16§or=car&band=GEOCOLOR&length=24
Don’t forget the two NOAA buoys that Beryl directly passed over and measured only cat 1 winds just before they conveniently stopped recording data.
Careful Mr Turner, you don’t want to be accused of spreading disinformation😉
Do those NOAA buoys measure the maximum sustained wind at 10 metres above absolute instantaneous sea level, or at at a lower altitude?
And are you suggesting that the stoppage in the recording was intentional?
Buoy anemometers are at different heights. Some are at 10m, but most are lower. Either way they are almost never located in the maximum sustained wind field and when they are they often do not survive to report the maximum sustained wind velocity.
I know that the collapse of the eye wall is significant, but I can’t remember what that collapse means. Can you expand on that?
Also, looks like there is another cyclonic storm following Beryl. Has that storm been named, and do we have any category information on it?
I don’t recall exactly myself but I think it indicates a weakening of the storm as it either moves over cooler water or is disrupted by land features
In general, what is apparent is that when a tropical system undergoes an eyewall replacement, the maximum winds decline immediately afterward. But I think, and observations seem to back this up, when there is an eyewall replacement the storm, in total, is getting stronger. I would give as an analogy a crab molting… during and immediately after the molt, the crab isn’t as strong, it’s more susceptible to predators, but after a bit (when the shell hardens) the crab is bigger and stronger overall and the shell is nearly always thicker than the one it just shed. I don’t know if that’s really a fact though, sounds like a great place to do research!!!
Here in the UK they have been hyping up Beryl with reports that it’s “unusual to get a cat 5 this early in the season”, and “exacerbated by CO2 emissions” etc. Most here won’t be inclined to check, so the propaganda gets spread around unchallenged.
Cat 5’s are unusual period, however we tend to have one most years, as to being early in the season, Andrew was earlier.
The official party line has been overblowing wind speeds of tropical systems for at least 7 years and it’s getting worse – the fudging that is. You used to be able to easily obtain the actual raw data from the Hurricane Hunter aircraft and when these revealed the official wind speed to be false, they have since made it difficult or impossible to find those raw data to reveal the emperor having no clothes.
I saw a shill on the Weather Channel interview a resident on one of the islands directly hit by Beryl, when they said it was a Cat 3, but he reported only Cat 1 or mere Tropical Storm force winds. The Shill didn’t bat an eyelash and simply moved along not acknowledging this blatant lie exposed.
Thanks for the details on this, very much appreciated.
Another good report from Jim Steele, thanks. As I’ve said before, La Niña is a bad girl, and now we see another contributing factor in action. By the way, Jim, I will be in Florida in 2 days for vacation with family, could you arrange to keep the hurricane track well to the south? Thanks.
I remember when hurricanes were categorized based on 10 m winds, not winds at thousands of feet altitude. Back when Cat 3 storms like Hurricane Dean caused catastrophic damage and death tolls when they passed over Caribbean islands. Luckily the propagandized categorization doesn’t cause literal damage.
Tell that to the residents of Carriacou!
“Officials said about 98 percent of the buildings on the islands, where about 6,000 people live, had been damaged or destroyed, including Carriacou’s main health facility, the Princess Royal Hospital, and its airport and marinas. As of Tuesday night, there was no electricity on either island, and communications were down. Crops had been ravaged, and fallen trees and utility poles littered the streets.
The natural environment also took a beating. “There is literally no vegetation left anywhere on the island of Carriacou, the mangroves are totally destroyed,” Mr. Mitchell said.”
Mandy Rice Davies applies perhaps?
Although I’ve no evidence either way.
Phil, I agree, Carriacou is badly damaged. However, consider, the Princess Royal Hospital (new, I think) is the size of two “18-wheelers” populating the highways of North America. Next, aid is already being sent to the effected islands. Also, prior to the early 1900s, it would take a week or two for this event to reach citizens in North America or Europe.
And finally, it is obligatory for some commentators to poo-poo 🙂 any and all reports from the NOAA & the NHC.
98%. Without real data that means that 2% of the buildings didn’t have awnings, or tacked on flimsy crap that would be damaged (or destroyed).
I have no doubt that there is significant damage on the island, but the phrasing of Mr. Mitchell (whoever that is) leads me to believe there is likely significant exaggeration. (If there is literally no vegetation left anywhere, I apologize publicly for expressing my doubts.)
I do though believe them when they say there was no electricity …
https://grenlec.com/renewable-energy/carriacou-wind-energy-project/
I look forward to the follow-up on how their solar & wind programs are working out for them.
Mr. Mitchell is the Prime Minister of Grenada.
Mr. Mitchell claims human-caused climate change is responsible for the hurricane.
Probably bidding for climate change money from the UN climate fund.
Or, maybe he’s a True Believer.
Robert, Where is it documented that wind categories are determined at thousands of feet altitude? I have always read the category is based on winds at 10 meters
That was sarcasm. It’s been the MO of NOAA to categorize storms about 1 to 2 categories higher than actual surface and satellite data suggests for at least the last 10 years.
I’ve not seen evidence of that. In fact, I’ve seen the opposite. They tend to ignore high surface wind measurements. For example, yesterday AF300-9 and NOAA3-8 measured 170 mph and 190 mph at the surface respectively. Yet despite these measurements the NHC did not go beyond 165 mph. I’m not saying it was wrong for them to do that. There are usually technical reasons for doing so. I’m just saying that the NHC does not exaggerate hurricane intensities.
Those aircraft flew 10 meters from the surface? That’s amazing! Hopefully you have the video
No. Hurricane hunter aircraft do not fly 10 meters from the surface.
Well you’re the one that said they ignore surface wind measurements and then immediately stated that two different hurricane hunters measured 170-190 mph winds.
And now the eye wall is hitting just west of Kingstown at this very moment and the NHC still maintains that Beryl has 140 mph sustained winds. The live cams show some flooded streets but barely enough wind to shake the cameras.
You mentioned Ian elsewhere. There are videos of young Florida men standing outside and unsheltered during the eye wall passing directly over them with purported Category 4 winds. It will become more common as more people think that it is safe to go stand in 130 mph sustained winds. That’s the danger of overstating the strength of these storms.
I didn’t say those aircraft fly 10 meters above surface. I said they measured surface winds of 170 and 190 mph and that despite this the NHC only set the intensity at 165 mph.
Serious question…did you really think they fly that low?
The most recent measurement by AF306-14 was 141 mph. That doesn’t mean it hasn’t weakened, but we’ll have to wait until the next update to see.
And I’ll remind you that the maximum wind field does not occur everywhere all at once. So if you think wind speeds are overstated first consider whether the observations you use to justify your position were actually colocated both spatially and temporally with the maximum wind field. This is the biggest source of confusion I see when people challenge the NHC categories.
Eyewall Wind Profiles in Hurricanes Determined By GPS Dropwindsondes (noaa.gov)
So says the National Hurrican Center
Dropsondes are certainly one way the vertical wind profile is determined. But the intensity category is still set based on the maximum wind velocity at the surface.
G’Day Jim,
“Where is it documented…”
At DuckDuckGo search: “At what altitude are hurricane wind speeds measured”.
From one of the articles:
The sudden drop-off
When a hurricane passes over open water toward the U.S. coast, wind observations come from five main sources:
—Reliable flight-level wind data measured directly from Hurricane Hunter aircraft, adjusted to the surface from measurement levels that are typically around 700 mb (3000 meters or 10,000 feet)
“Category” seems to come from the highest wind speeds found anywhere in the hurricane body.
I also use ‘earth.nullschool’. Two mornings ago at sea level the highest wind reading I could find was 81mph. At 700 hPa – over 140 mph. Pressure in the eye: 980, then yesterday 990, this morning 995, and 996 about 10 minutes ago.
Hurricanes categories are still based on surface winds.
BTW…In reading comments in this blog post and the older posts regarding Hurricane Ian I think there is confusion on how hurricane intensities are set. It is important to note that they are not set based only on the maximum surface wind speed measured by a buoy or land station. I mean it could be if it is truly the maximum, but it almost never is especially for intense hurricanes because 1) those instruments are not usually colocated with the maximum wind and 2) they don’t usually survive long enough even when they are. The most common way the maximum wind is measured is via dropsondes and SFMR both of which can 1) target the maximum wind and 2) survive long enough to actually sample and report the maximum wind velocity.
“The most common way the maximum wind is measured is via dropsondes and SFMR both of which can 1) target the maximum wind…”
… anywhere in the body of the hurricane, and typically found around 10,000 ft. Those wind speed numbers make for great headlines.
Regardless of what the media reports the official updates from the NHC uses the maximum surface winds for assignment of categories.
And what does that tell us about the “media”?
You shouldn’t rely on complex technical and scientific related information including and especially anything related to the weather/climate from the media.
Jim ==> Extremely informative. Great stuff.
There is so much to learn in the time saved by not listening to MSM.
As the original post says :”Hurricane intensification is controlled by 3 dynamics. 1) Energy supplied by sea surface temperatures;…” Well 1) might be a factor in this case!
https://pbs.twimg.com/media/GRVqxYAbcAASoaH?format=jpg&name=small
Earth Science textbooks from 75 years ago stated as much. The current findings suggest the first condition is that ocean waters must be above 26°C (79°F). More here:
https://www.weather.gov/source/zhu/ZHU_Training_Page/tropical_stuff/hurricane_anatomy/hurricane_anatomy.html
Indeed summer warming of the Atlantic provides warmer water, via direct solar heating or advection, enables hurricane season. However there is often a Temperature Paradox, where a hurricane intensifies as it travels over cooler SSTs. Take Hurricane Ian in September 2022 for example. Ian intensified from a Cat1 at Jamaica’s latitude to Cat 4 before landfall over Florida despite SST falling by 3.6 C.
Sorry, I attached the ocean temperature distribution that preceded Beryl, for some reason something else showed up!
https://pbs.twimg.com/media/GRVqxYAbcAASoaH?format=jpg&name=small
Thanks Jim,
This is an educational and interesting report.
The following Easterly Wave, DISTURBANCE INVEST 96 (AL96) …
{I’ve no idea where the naming comes from}
… appears to be suffering from a lack of energy, that powered Beryl.
Officially it is 96L. The L means North Atlantic. All invests begin with 9. The second digit is the sequential number of the invest beginning the season at 1 and rotating back to 90 for the 10th invest. Numbers are recycled through the season.
While we have long known about river effects it is great to see such an interest, ocean is slower but important. Computers and satellites are useful but were distracting.
Ryther, J. H., et al., 1967. Influence of the Amazon River Outflow on the Ecology of the Western Tropical Atlantic. I. Hydrography and Nutrient Chemistry. Journal of Marine Research. 25(1):69-83.
“The Amazon River discharges some 2 X 10fifth cubic meters of water per second-five times that of the Congo, the worlds second largest river, twelve times that of the Mississippi, and approximately18% of the total river discharge in the world. (Davis 1964.)”
Every submariner knows about barrier layers. They greatly affect the propagation of sound in water, and hence the performance of sonar. A sub is sometimes able to escape detection by exploiting these barriers.
The simplistic, univariate (sea surface temperature) explanation of hurricane dynamics in most media and government accounts ignores a ubiquitous characteristic of the ocean environment in which hurricanes spend virtually all their existence.
The NHC does not like Accuweather beating them to the punch.
Community Note on X disregards AccuWeather’s mission to save lives and safeguard communities
“WHY HURRICANES INTENSIFY”
is like asking “why do dogs lick their d1cks”
The answer is the same –
“because they CAN”
Sometimes they “peter” out.
In the article you talk about the conditions necessary for creating a storm, but you do not mention the mechanics of storm formation. May I give you a simplified explanation of the mechanics.
You say that the ‘Energy (for the storm is) supplied by sea surface temperatures’. This is technically correct, but the mechanics of it is that the sea surface temperature provides the energy for water evaporation, and it is the evaporation of water from the sea surface that transfers the energy from the sea to the atmosphere.
The rate of water evaporation from the sea surface is proportional to 1) the equilibrium vapor pressure of water at the sea surface, 2) the wind speed and 3) the surface area available for evaporation.
The properties of water create the conditions for transforming the normally tame evaporation process into a self-feeding out of control process if the water temperature increases beyond a minimum value (approximately 26 C as noted in the article).
Firstly, the equilibrium vapor pressure of water at the sea surface increases exponentially with temperature, increasing roughly 7% per degree C.
Secondly, water vapor is approximately 40% less dense than air. Thus, the more water evaporation, the more water vapor in the air near the sea surface, and the greater the density differences with dry air. These density differences cause wind.
Thirdly, the surface tension of the water-air interface is such that a small amount of wind will cause waves, and if the waves are big enough to cause broken surface, the surface area available for water evaporation increases dramatically.
Fourthly, on the other hand, the very high latent heat of evaporation of water, means that high rates of evaporation very effectively cool the water surface, resulting in the storm’s relatively rapid self-destruction.
Thus, at sea-surface temperatures above approx. 26 C, with the help of an initial wind disturbance, the rate of water evaporation is sufficient to cause an increase in wind, which further increases water evaporation which further increases wind, generating waves, which dramatically increases water evaporation, causing a dramatic increase in wind, in a self-reinforcing feedback loop that only stops when the water has been over-cooled, to the point that the rate of evaporation, even with the high winds and waves, is insufficient to maintain the storm.
At sea-surface temperatures approaching 30 C. this process can be auto-initiated with out an initial wind disturbance, which is why sea-surface temperatures rarely exceed 30C.
You state that Barrier Layers are key for understanding intensification. I would add that shallow waters likely play the same role, as there is less of a heat sink at greater depth to absorb solar radiation. In the same sense, the plumes of fresh water from the Amazon River basins also likely contain a lot of silt that will absorb the solar radiation and cause the surface waters to heat more quickly.
As an aside, I would propose that the same process of storm formation, described above, is the process that underlies the El Nino oscillation, but only on an orders of magnitude larger scale.
Everyone knows that CO2 heats ocean water up several degrees because it acts like a blanket and causes hurricanes to strengthen.
I’ve heard that over and over on CNN and MSNBC for the last week from the “experts”.
So now that Beryl directly hit Jamaica as a purported Cat 4 – damaging tin sheet structures – and Cancun as a purported Cat 2 – doing no visible wind damage – are we still pretending that the NHC isn’t over reporting sustained wind speeds?