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This comment does NOT reflect the science as I understand it, even as quoted in the article in post 1: <<[Argo data] helped NOAA predict that Hurricane Ida would grow rapidly because forecasters could see that there was no cold water deep down beneath the storm that would get churned up and mix with warm surface waters.>> Upwelling of cold water actually would diminish a hurricane, as noted in the following discussion.
Before the Argo sensors, there was no easy way to know the sub-surface temperatures. "Nothing new" and "not new info here" are typical phrases used by persons eager to dismiss climate change.
Nothing new?
Actually, the NOAA's greatly improved forecasting of Hurricane Ida's rapid intensification did result from something new:
<<The supercharging of Hurricane Ida was less of a surprise than [2020's Hurricane] Laura’s, in part because of changes made to a network of floating ocean temperature sensors known as Argo, run by an international consortium of scientific agencies. This year, NOAA increased the frequency of reports from the Argo floats, to every two days instead of every 10. With more timely information, NOAA forecasters saw that Ida was headed toward a very warm blob of subsurface sea water. If the deep water in the path of a storm that’s churned up by surface winds is cold, it tends to reduce the storm’s power.>>
By successfully forecasting Ida's rapid intensification, perhaps for the first time in hurricane forecasting, the resulting evacuations perhaps saved many lives.
And the entire Argo project is new to the 21st century and is under constant improvement, as just noted.
<<However, until Argo began in 1999, the lack of both systematic worldwide observations of key factors that influence climate and the lack of accurate models that use observational data in climate forecasting made understanding and predicting these changes difficult.>>
The Bloomberg article is the first time that I learned of Argo sub-surface temperatures being incorporated successfully into an NOAA hurricane rapid intensification forecast. Please provide me with an earlier example. Even the following November 2020 article lamented the lack of sub-surface water temperatures available to hurricane forecasters, so increasing the frequency of Argo reporting in 2021 represents a major advance in hurricane intensity forecasting.
<<Heat stored in the ocean is energy that feeds storms. The warmer the water, the more energy is available for a storm to build strength. Winds from storms blow across the ocean and stir warm surface water with cooler water deeper down. The cooler the water rising to the surface, the less energy is delivered to the storm, which saps the storm’s strength. However, if the deeper water stirred to the surface is warm, it acts as fuel driving a storm’s intensity higher.
Scientists can easily measure the sea surface temperature (SST), but that provides no information about how much energy is stored below the surface.>>
<<However, errors related to forecasting hurricane (rapid) intensification show much less improvement, with pronounced spikes in the number of errors year to year, mostly because of the lack of data — particularly the ocean data below the surface....
Underwater gliders powered by batteries have been successfully used to collect data in support of hurricane forecasting. NOAA, the U.S. Navy, the U.S. Integrated Ocean Observing System (IOOS) and academic partners deployed 30 gliders for the 2020 hurricane season. The fleet of gliders is expected to transmit 50% more data from the ocean compared to previous years.
That’s a great start, but to greatly improve the hurricane intensity forecast, we need to increase the subsurface ocean measurements by at least one order of magnitude, which can only be done with innovation with game-changing technology to power the Blue Economy.
One of the most ambitious efforts to gather subsurface data is Argo, an international program designed to build a global network of 4,000 free-floating sensors that gather information like temperature, salinity and current velocity in the upper 2,000 meters of the ocean.>>
It's also false to imply that hurricane strength runs in cycles. Measured ocean heat content and hurricane rapid intensification are increasing sequentially, with even greater devastation expected in the future.
From a 2018 article lamenting our inability to forecast rapid intensification of hurricanes:
<<In a 2016 paper, “Will Global Warming Make Hurricane Forecasting More Difficult?” (available here from the Bulletin of the American Meteorological Society), MIT hurricane scientist Kerry Emanuel explained that not only will global warming make the strongest hurricanes stronger, it will also increase how fast they intensify. Troublingly, intensification rates don’t increase linearly as the intensity of a storm increases--they increase by the square power of the intensity. Thus, we can expect future hurricanes to intensify at unprecedented rates, and the ones that happen to perform their rapid intensification just before landfall will be extremely dangerous.
Dr. Emanuel used a computer model that generated a set of 22,000 landfalling U.S. hurricanes during the recent climate period of 1979 - 2005, then compared their intensification rates to a similar set of hurricanes generated in the climate expected at the end of the 21st century. For the future climate, he assumed a business-as-usual approach to climate change—the path we are currently on. The analysis found that the odds of a hurricane intensifying by 70 mph or greater in the 24 hours just before landfall were about once every 100 years in the climate of the late 20th century. But in the climate of the year 2100, these odds increased to once every 5 - 10 years. What’s more, 24-hour pre-landfall intensifications of 115 mph or more—which were essentially nonexistent in the late 20th Century climate—occurred as often as once every 100 years by the year 2100. The major metropolitan areas most at risk for extreme intensification rates just before landfall included Houston, New Orleans, Tampa/St. Petersburg, and Miami.>>
Ida's 75 mph rapid intensification level would top a listing of hurricane rapid intensification measurements listed in the Weather Underground article above.
Why do and others make inaccurate, UNSUBSTANTIATED statements about matters about which they obviously are ignorant???
This forum is riddled with inaccurate scientific claims about hurricanes.
I don't read long windy posts, but I certainly agree with your last sentence.
Hurricane rapid intensification is nothing new, South Florida experienced it first hand with Andrew in 1992. Atmospheric conditions can change over hours allowing a storm to quickly generate strength.
<<“It’s a known effect of climate change. Increasing ocean heat is causing strong hurricanes to become stronger,” said Greg Foltz, an oceanographer with the National Oceanic and Atmospheric Administration....
Multiple studies have shown that rapid intensification has increased over the past three decades, pushing large storms to become even larger. In the 24 hours before Hurricane Harvey made landfall in 2017, for example, its winds jumped from 90 mph to 130 mph — the difference between a Category One storm and a Category Four storm. In 2018, Hurricane Michael’s winds increased in speed by 45 mph in the last 24 hours before reaching in Florida.
The reason hurricanes are getting more powerful with such speed is no secret: warmer ocean water. “Surface temperatures in the Gulf now are about 0.5° Celsius to 1°C above the 1971 to 2000 mean,” said Foltz. “This gives more fuel to hurricanes and increases their wind speed limit.”>>
A deep eddy of very warm ocean water also contributed to Ida's rapid intensification. A map accompanying the article indicates that sub-surface sensors show that Florida is surrounded by very warm sub-surface ocean water. As a result, any hurricane making landfall in Florida this year likely will undergo rapid intensification.
<<Before hurricane season, Foltz said the floats in the Gulf were programmed to surface every 10 days to transit their data via satellite. NOAA then switched the program to every two days to create a more continuous flow of data for hurricane season.
This helped NOAA predict that Hurricane Ida would grow rapidly because forecasters could see that there was no cold water deep down beneath the storm that would get churned up and mix with warm surface waters. The Argo sensors also revealed that water in the storm’s path was predominately saline, another factor adding to intensification.>>
Hurricanes create an "upwelling" of ocean water, so warm subsurface water sustains hurricanes and provides the additional fuel for rapid intensification, according to the article.
Hurricane rapid intensification is nothing new, South Florida experienced it first hand with Andrew in 1992. Atmospheric conditions can change over hours allowing a storm to quickly generate strength.
As noted in post 1, what has changed is that the oceans are warmer and rapid intensification has increased since 1990.
<<The world’s oceans reached their hottest level in recorded history in 2020, supercharging the extreme weather impacts of the climate emergency, scientists have reported.
More than 90% of the heat trapped by carbon emissions is absorbed by the oceans, making their warmth an undeniable signal of the accelerating crisis. The researchers found the five hottest years in the oceans had occurred since 2015, and that the rate of heating since 1986 was eight times higher than that from 1960-85.
Reliable instrumental measurements stretch back to 1940 but it is likely the oceans are now at their hottest for 1,000 years and heating faster than any time in the last 2,000 years. Warmer seas provide more energy to storms, making them more severe, and there were a record 29 tropical storms in the Atlantic in 2020.>>
Following is the research paper on which the above article is based. Note in Figure 1 that not only have surface temperatures increased, but so have sub-surface temperatures, especially up to 500 meters deep.
<<One characteristic of the 2020 season that will be discussed for quite a while is the rapid intensification of storms. Ten storms so far this year have seen sustained winds gain 35 mph or more in speed within 24 hours or less, with Eta and Iota beating all records with 80 mph increases as they neared landfall on the coast of Nicaragua. The 1995 season also had 10 rapidly intensifying storms – but not at the same rate. Some scientists argue that rapid intensification is likely to become a more common feature of future storms, making forecasting trickier. Research has shown that rapid intensification, observed over the past 40 years, has become more frequent, a pattern that is not supported by models of internal climate variation alone, suggesting that human-caused global warming might be a factor. Another study determined that the chance of a hurricane intensifying went from 1 in 100 in the early 80s to 1 in 20 by mid-2005.>>
Experts praise NHC rapid intensification forecast for Ida
At least for Hurricane Ida, the National Hurricane Center accurately predicted a rapid intensification from the onset of its forecasts.
<<University of Miami hurricane researcher Brian McNoldy lauded the forecast even from the very first predictions. "In the first forecast made for Tropical Depression Nine (on Thursday), the NHC made the exceptional call to include rapid intensification in their forecast," he said.
"That forecast was shockingly confident, and something we almost never see," McNoldy said.
James Franklin, a part-time contractor at the NHC with the Hurricane Forecast Improvement Project, said, "60 hours of lead time advertising a major hurricane at landfall is admirable.">>
Ian became the seventh rapidly intensifying hurricane to make landfall in the U.S. since 2017.
<<Since 2017, an unprecedented number of storms rated Category 4 or stronger have lashed the U.S. shoreline: Harvey, Irma, Maria, Michael, Laura, Ida and now Ian. They all qualify as “rapid intensification events,” when a storm’s wind speeds increase by at least 35 mph within 24 hours.
These kinds of storms have increased in number in recent decades. Sixteen of the 20 hurricanes over the past two seasons in the Atlantic basin have undergone rapid intensification....
Ian was only the latest case when its winds nearly doubled within a 24-hour period, going from a low-end hurricane with sustained 75 mph winds Monday to a Category 3 storm with 125 mph winds Tuesday. Then, as it approached Florida on Wednesday, its winds surged even faster, going from 120 mph around 2 a.m. to 155 mph by 7 a.m.>>
<<One study published earlier this year found that since 1990, a steadily growing number of global tropical cyclones have undergone what the study called “extreme rapid intensification,” with winds increasing by at least 50 knots, or 57 mph, within a 24-hour period. Another study from 2018 focused on the Atlantic basin found that among cyclones that have strengthened the most rapidly, their rates of intensification have accelerated, growing by about 4 mph each decade over the past 30 years.>>
Buried in the above article is an ominous discussion of the impact of climate change on wind shear. This impact will result from the expected northward shift of the jet stream in coming decades, not from warming oceans that directly power rapid intensification.
<<
Vertical wind shear — changing wind speeds and direction at different altitudes in a storm — is also a key influence on the intensity of hurricanes, although researchers are still deciphering any long-term trends. High wind shear can weaken a hurricane, while weaker shear can help a hurricane form and strengthen.
Wind shear has been relatively low in the western Atlantic since 2017, a factor that has contributed to the flurry of tropical cyclones since then, according to Klotzbach. It’s possible that in the long run, climate change could make this environmental condition more common. Scientists hypothesize that the jet stream, which creates strong wind shear, could be pushed north as global temperatures rise.>>
This Scientific American article discusses the northward shift in the jet stream.
<<A new study finds that the jet stream could shift outside the bounds of its historic range within just a few decades — by the year 2060 or so — under a strong warming scenario. The findings were published last week in the journal Proceedings of the National Academy of Sciences.>>
Ian became the seventh rapidly intensifying hurricane to make landfall in the U.S. since 2017.
<<Since 2017, an unprecedented number of storms rated Category 4 or stronger have lashed the U.S. shoreline: Harvey, Irma, Maria, Michael, Laura, Ida and now Ian. They all qualify as “rapid intensification events,” when a storm’s wind speeds increase by at least 35 mph within 24 hours.
These kinds of storms have increased in number in recent decades. Sixteen of the 20 hurricanes over the past two seasons in the Atlantic basin have undergone rapid intensification....
Ian was only the latest case when its winds nearly doubled within a 24-hour period, going from a low-end hurricane with sustained 75 mph winds Monday to a Category 3 storm with 125 mph winds Tuesday. Then, as it approached Florida on Wednesday, its winds surged even faster, going from 120 mph around 2 a.m. to 155 mph by 7 a.m.>>
<<One study published earlier this year found that since 1990, a steadily growing number of global tropical cyclones have undergone what the study called “extreme rapid intensification,” with winds increasing by at least 50 knots, or 57 mph, within a 24-hour period. Another study from 2018 focused on the Atlantic basin found that among cyclones that have strengthened the most rapidly, their rates of intensification have accelerated, growing by about 4 mph each decade over the past 30 years.>>
Buried in the above article is an ominous discussion of the impact of climate change on wind shear. This impact will result from the expected northward shift of the jet stream in coming decades, not from warming oceans that directly power rapid intensification.
<<
Vertical wind shear — changing wind speeds and direction at different altitudes in a storm — is also a key influence on the intensity of hurricanes, although researchers are still deciphering any long-term trends. High wind shear can weaken a hurricane, while weaker shear can help a hurricane form and strengthen.
Wind shear has been relatively low in the western Atlantic since 2017, a factor that has contributed to the flurry of tropical cyclones since then, according to Klotzbach. It’s possible that in the long run, climate change could make this environmental condition more common. Scientists hypothesize that the jet stream, which creates strong wind shear, could be pushed north as global temperatures rise.>>
This Scientific American article discusses the northward shift in the jet stream.
<<A new study finds that the jet stream could shift outside the bounds of its historic range within just a few decades — by the year 2060 or so — under a strong warming scenario. The findings were published last week in the journal Proceedings of the National Academy of Sciences.>>
Katrina is a perfect example, it passed through South Florida as a Cat 1 and just one day before landfall it became a Cat 5, just like that.
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Experts praise NHC rapid intensification forecast for Ida
