Radar image Hurricane Laura

Hurricane Laura put on a phenomenal show of rapid intensification prior to landfall, increasing in strength by 65 mph in just 24 hours on August 26, 2020. That ties Hurricane Karl of 2010 for fastest intensification rate in the Gulf of Mexico on record. In the 24 hours prior to landfall, Laura’s winds increased by 45 mph, and the mighty hurricane made landfall in western Louisiana as a category 4 storm with 150 mph winds – the strongest landfalling hurricane in Louisiana history, and the fifth-strongest hurricane on record to make a continental U.S. landfall.

Laura’s rapid intensification was a disturbing déjà vu of what had happened just two years earlier.

Analysis

As Hurricane Michael sped northwards on October 9, 2018, towards a catastrophic landfall on Florida’s Panhandle, the mighty hurricane made an exceptionally rapid intensification. Michael’s winds increased by 45 mph in the final 24 hours before landfall, taking it from a low-end category 3 hurricane with 115 mph winds to catastrophic category 5 storm with 160 mph winds. And Michael’s performance echoed what had happened in 2017, when Hurricane Harvey rapidly intensified by 40 mph in the 24 hours before landfall, from a Category 1 storm with 90 mph winds to a Category 4 storm with 130 mph winds.

Human-caused climate change causing more rapidly intensifying Atlantic hurricanes

Unfortunately, not only is human-caused climate change making the strongest hurricanes stronger, it is also making dangerous rapidly intensifying hurricanes like Laura and Michael and Harvey more common.

According to research published in 2019 in Nature Communications, Atlantic hurricanes showed “highly unusual” upward trends in rapid intensification during the period 1982 – 2009, trends that can be explained only by including human-caused climate change as a contributing cause. The largest change occurred in the strongest 5% of storms: for those, 24-hour intensification rates increased by about 3 – 4 mph per decade between 1982 – 2009.

Led by hurricane scientist Kieran Bhatia of NOAA’s Geophysical Fluid Dynamics Laboratory – and titled “Recent increases in tropical cyclone intensification rates” – the study used the HiFLOR model to simulate intense hurricanes. HiFLOR is widely accepted as the best high-resolution global climate model for simulating intense hurricanes.

Dangerous scenario – rapidly intensifying hurricane making landfall

Rapidly intensifying hurricanes like Michael and Harvey that strengthen just before landfall are among the most dangerous storms, as they can catch forecasters and populations off guard, risking inadequate evacuation efforts and large casualties. A particular concern is that intensification rate increases are not linear as the intensity of a storm increases – they increase by the square power of the intensity.

Lack of warning and rapid intensification just before landfall were key reasons for the high death toll from the 1935 Labor Day hurricane in the Florida Keys, the most intense hurricane on record to hit the U.S. That storm intensified by 80 mph in the 24 hours before landfall, and it topped out as a Category 5 hurricane with 185 mph winds and an 892 mb pressure at landfall. At least 408 people were killed, making it the eighth-deadliest hurricane in U.S. history.

Another rapidly intensifying hurricane at landfall, Hurricane Audrey in June 1957, tracked on nearly the same course as Hurricane Laura. Audrey was the seventh deadliest U.S. hurricane, killing at least 416. Its winds increased by 35 mph in the 24 hours before landfall near the Texas/Louisiana border as a Category 3 hurricane with 125 mph winds. Lack of warning and an unexpectedly intense landfall were cited as key reasons for the high death toll.

With today’s satellites, radar, regular hurricane hunter flights, and advanced computer forecast models, the danger that another Audrey or 1935 Labor Day hurricane could take us by surprise is lower.

Video: Jeff Masters on 2019 Hurricanes

But all of that sophisticated technology didn’t help much for 2007’s Hurricane Humberto, which hit Texas as a Category 1 storm with 90 mph winds. Humberto had the most rapid increase in intensity, 65 mph, in the 24 hours before landfall of any Atlantic hurricane since 1950. A mere 18 hours before landfall, the National Hurricane Center (NHC) in 2007 had predicted a landfall intensity of just 45 mph, increasing its forecast estimate to 65 mph six hours later. It’s fortunate that Humberto was not a stronger system, as the lack of adequate warning could have led to serious losses of life.

Historical records show that since 1950, the eight storms have intensified by at least 40 mph in the 24 hours before landfall. It is sobering to see three of those storms, below in bold face, occurred in the past four years:

Humberto, 2007 (65 mph increase);
King 1950 (60 mph increase);
Eloise 1975 (60 mph increase);
Danny 1997 (50 mph increase);
Laura 2020 (45 mph increase);
Michael 2018 (45 mph increase);
Harvey 2017 (40 mph increase);
and
Cindy 2005 (40 mph increase).

Extreme rapid intensification rates just before landfall to become more common

In a 2016 study – “Will Global Warming Make Hurricane Forecasting More Difficult?” from the Bulletin of the American Meteorological Society – MIT hurricane scientist Kerry Emanuel used a computer model that generated a set of 22,000 landfalling U.S. hurricanes between 1979 and 2005. Emanuel 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. Emanuel found that the odds of a hurricane intensifying by 70 mph or more 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, essentially nonexistent in the late 20th-century climate, would occur as often as once every 100 years by the year 2100. Emanuel found that major metropolitan areas most at risk for extreme intensification rates just before landfall included Houston, New Orleans, Tampa/St. Petersburg, and Miami.

Figure 1. VIIRS image of Super Typhoon Haiyan at 1619 UTC November 7, 2013. Haiyan at that point was about to make landfall near Tacloban in the Philippines with 190 mph winds, the strongest land-falling tropical cyclone in recorded history. (Image credit: NOAA/CIRA)

Eight-fold increase in ultra-intense hurricanes predicted

The same HiFLOR high-resolution global climate model for simulating intense hurricanes referenced above produced some rather startling findings detailed in a 2018 paper, Projected Response of Tropical Cyclone Intensity and Intensification in a Global Climate Model.

The scientists who authored that paper forecast a dramatic increase in the global incidence of rapid intensification as a result of global warming, and a 20% increase in the number of major hurricanes globally.

For the Atlantic, the model projected an increase from three major hurricanes per year in the climate of the late 20th century, to five major hurricanes per year in the climate of the late 21st century.

The HiFLOR model also predicted a highly concerning increase in ultra-intense Category 5 tropical cyclones with winds of at least 190 mph – from an average of about one of these Super Typhoon Haiyan–like storms occurring once every eight years globally in the climate of the late 20th century, to one such megastorm per year between 2081 to 2100 – a factor of eight increase.

Even more concerning was that the results of the study were for a middle-of-the road global warming scenario (called RCP 4.5), which civilization will have to work very hard to achieve. Under the current business-as-usual track, the model would be expected to predict an even higher increase in ultra-intense tropical cyclones.

One technique for computing hurricane damage uses ICAT’s damage estimator to review all contiguous land-falling U.S. hurricanes between 1900 – 2017. That technique computes the amount of damage they would do currently and corrects for changes in wealth and population. It finds that while Category 4 and 5 hurricanes made up only 13% of all U.S. hurricane landfalls during that period, they caused 52% of all the hurricane damage.

Given that assessment, it’s very concerning that the HiFLOR model, the best model for simulating current and future behavior of Category 4 and 5 hurricanes, is predicting a large increase in the number of these destructive storms. Even more concerning is the model’s prediction of a global factor of eight increase in catastrophic Category 5 storms with winds of at least 190 mph by the end of the century – and that under a moderate global warming scenario.

All of which leads to the regrettable conclusion that the prospects for quickly intensifying storms as they approach landfall are likely to increase in a warming world.

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Posted August 27, 2020, at 3:56 p.m. EDT.

Jeff Masters

Jeff Masters, Ph.D., worked as a hurricane scientist with the NOAA Hurricane Hunters from 1986-1990. After a near-fatal flight into category 5 Hurricane Hugo, he left the Hurricane Hunters to pursue a...

288 replies on “Climate change is causing more rapid intensification of Atlantic hurricanes”

  1. The ridge dominating the Gulf is forecast to lift north by mid week, steering looks pretty straight forward. 500mb steering pictured. hard to see how 99L goes anywhere but across Central America into the Pacific. LLC would have to form way north by the strongest convection for 99L to make the Yucatan, much less the Gulf. None of the latest vorticity maps suggest that is happening. http://tropic.ssec.wisc.edu/real-time/atlantic/winds/wg8dlm2.GIF

  2. 99L under very low shear. To have a massive wall of mid-level dry air to the north and west is the suppresser; but I’m not sure the almost nil shear won’t allow 99L to form quickly and create it’s own environment which may be able to keep the dry air out. 99L finds it’s footing, may spell trouble of becoming the next hurricane of 2020. http://tropic.ssec.wisc.edu/real-time/atlantic/winds/wg8shr.GIF

    1. Mid-level trough is narrow and draped from Haiti to Panama. This trough is the only area where shear is going up. Looks to be having some negative impacts on 99L’s development for now. 500mb vorticity pictured first showing trough. Shear tendency map highlighting the increased shear to the west of 99L. At the upper levels a big TUTT is seen over the western Caribbean. Could be another negative factor downstream. http://tropic.ssec.wisc.edu/real-time/atlantic/winds/wg8sht.GIF http://tropic.ssec.wisc.edu/real-time/atlantic/winds/wg8vor2.GIF

  3. What’s going on with the rising, sinking air anomaly? Forgive me for the unscientific wording. If I’m not mistaken that means a depression of cyclone activity in the Atlantic MDR over the next couple of weeks?

    1. Suppressed phase of the MJO has moved into the Western Hemisphere, specifically the eastern portion. Yet it’s a low frequency suppressed phase which means storms will still keep on rolling. To be in a suppressed phase, with shear across the Atlantic and Caribbean still so low, suggests to me we may not be getting any slowdown.

  4. 99L has an even more favorable shear environment today. Very dry mid-level air in 99L’s path; but considerably less than yesterday. With very low shear, what dry air is there, will likely not entrain quickly when 99L does develop. Watching an invest move in low shear through the eastern Caribbean is a unique sight. Low Level about to crash into Venezuela, mid level should take over and work down. 99L very well may not be Mexico bound if the low level dies. https://cdn.star.nesdis.noaa.gov/GOES16/ABI/SECTOR/taw/08/1800×1080.jpg

      1. Keep posting, it will get worked out. Your “well constructed” post rambled off about someone else and had the word troll or trolling in it, which probably triggered the commenting platform.

      2. Well, that’s pretty prohibitive of communication then, isn’t it (rhetorical … it is.)
        I won’t bother rewriting the comment again, the misleading comment I was responding to … the logical fallacy that was made … will stand un refuted.

        I’ll wait till a new system comes before engaging other crucial topics like the Buffet/Gates topic below, because the system is too random at the moment to facilitate discussions requiring any modicum of depth and nuance.

        As it stands, it’s just a frustrating barrier to discussion. Good luck with getting set up.

      3. And now, several comments from this thread are gone. Mine, and another from another poster, who had added a comment.

        Streamlined? Filtering out the flow of the content? Why? Just, tidying?

        I look at sociology and psychology a lot while processing climate change and in particular human responses to it. All the comments on a board, are useful to the work I do, socially, regarding climate … and particularly removing social barriers to addressing the climate issue.

        It’s such a slow moving board. Why on earth would the two innocuous comments have been removed from this thread, especially if it was just for tidying reasons? Why not, just leave them be.

        That, filters all the content through just one person’s thinking process at any given time; one mod. The more that happens, the less hands off you are with that privilege, the more un-real and distorted things will become. That’s because you may not be considering what it is I might be focused on while watching behavior and conversations evolve on a message board.

        That’s a social system observation for you. This place has some thinking to do between now and a new system about who it actually wants to be in the climate discussion. Right now, this isn’t serious.

      4. Skyepony, should we expect this to be the going rate of YCC blog, until the new format in November?

      5. Thanks for the useful information, Wyatt. Come back in Novemeber was the right answer here, not … keep posting, while I distort and mangle your content for you, and also your context while I’m at it. People have flocked here, and then leave almost immediately. You have lurkers, but no commenters. I will come back in November and see if things have changed. Thanks for the heads up Wyatt.

  5. Japan Meteorological Agency
    Tropical Cyclone Advisory #31 – 21:00 PM JST August 31 2020
    TYPHOON MAYSAK (T2009)
    =================================================
    140 km southwest of Naha (Okinawa Prefecture)

    At 12:00 PM UTC, Typhoon Maysak (950 hPa) located at 25.0N 127.2E has 10 minute sustained winds of 85 knots with gusts of 120 knots. The cyclone is reported as moving north northwest at 11 knots.

    Storm Force Winds
    ===================
    100 nm from the center

    Gale Force Winds
    ===================
    300 nm from the center in eastern quadrant
    240 nm from the center in western quadrant

    Dvorak Intensity: T5.5

    Forecast and Intensity
    =======================
    24 HRS: 28.4N 125.7E – 95 knots (CAT 4/Very Strong Typhoon) East China Sea
    48 HRS: 32.8N 127.5E – 90 knots (CAT 4/Very Strong Typhoon) 120 km west of Goto (Nagasaki Prefecture)
    72 HRS: 43.8N 126.3E – 55 knots (CAT 2/Severe Tropical Storm) Over land northeastern China

    —–

    Tropical Cyclone Advisory #3 – 21:00 PM JST August 31 2020
    TROPICAL DEPRESSION 11
    =================================================
    near Ogasawara islands

    At 12:00 PM UTC, Tropical Depression (1008 hPa) located at 22.9N 146.1E has 10 minute sustained winds of 30 knots. The depression is reported as moving southwest at 8 knots.

    Dvorak Intensity: T1.5

    Forecast and Intensity
    =======================
    24 HRS: 23.0N 144.0E – 35 knots (CAT 1/Tropical Storm) near Ogasawara islands

  6. Latest updates at my site for all four areas of interest went up at about midnight last night, again practicing doing updates from the cellphone (thus the satellite and chart markups are simpler than they usually are). Resuming normal updates later today with the usually charting.

    If in fact 90L offshore of the eastern US coast becomes our next tropical storm, it would join Arthur, Bertha, Dolly, Edouard, Fay, and Kyle in developing in the northwest Atlantic from a decaying frontal zone. This recurring pattern this season seems to be pumping up the numbers of storms we’ve had so far, explaining the record number of Atlantic storms we’ve had this season so far.

  7. Active Climate Rescue Initiative: Move the Water! is aimed at reversing Global Warming.
    .
    Fully implemented, Move the Water! initiative would greatly affect Global Warming and improve the lives of many people around the world.
    .
    Partly implemented, Move the Water! initiative will slightly affect Global Warming and greatly improve the lives of people local to the individual site.
    .
    See 2-minute short videos for initiative overview.
    https://youtu.be/vRJyCVXApAk
    https://youtu.be/bjHxkxRWAs0

    1. The idear is good, however impossible to practice in this world in the state it is with governements we have that only can think of their own profit and power. For that reason just impossible.

  8. If the eastern Atlantic tropical waves aren’t moving, does that mean the trades have collapsed and that the oceans will warm up further with a lack of wind?

  9. A note for those monitoring the solar energy field in America.
    Large Corporations in America, especially any connected to utilities, are trying to kill and hinder solar energy progress big time.
    I once worked for Haleakala solar, the most successful solar outfit in Hawaii just 2-25 years ago.
    They were bought put by Petersen-Dean – to kill it.
    When they bought the company nearly all the electricians quit right off the bat.
    Too much cumbersome corporatization. 
    Excess paperwork for in the field electricians is BS.
    Too many high paid bosses who didn’t know jack about solar too.
    The same happened with another company I worked for – REC.
    Duke Energy – a major utility in the eastern US bought them out in 2015.
    Their business has gone through the floor since.
    Corporate America is doing its damndest to kill solar.
    Screw the large corporations – shun them.
    Go with a local solar operator that still has enough clout to provide and install battery back-up, the best way to ensure you receive the benefits instead of some friggin utility or large corporation. 
    You’ll get better prices and a better outcome financially and your company is less likely to go out of business on you if you ever need help/upgrades/battery backup.
    You’re more likely to reap the financial benefits as well.

    1. hopefully you are not a bot Matt, anyway, your basic premise is correct.

      Warren Buffet makes a lot of talk of how he is stepping up with green energy:

      https://archive.thinkprogress.org/buffett-says-he-loves-renewables-so-why-is-his-company-trying-to-kill-solar-energy-77a6941bafc1/

      Don’t forget, he is the same guy who own burlington northern, the main US railroad used to transport fracked and shale oil to other countries. I call bs on his aw shucks story.

      His giving pledge pal billy bathgates, owns a huge interest in Canadian National Railroad,
      so much, that they had to modify the law about foreigners ownership limits, just for billy.

      This is how all the alberta tar sands oil, which is the filthiest fossil fuel extraction that exists, gets to market.

      CNN routinely has articles quoting bill gates like he is some freaking oracle or something,
      good god, he is a just a rich dude, and do you think he got rich by being some kind of great, sympathetic guy, he rode roughshod. Google (<-don’t be evil – haha – so ironic) his history.

  10. One gathers it’s now casting as the MJO and the Model’s aren’t in a dating mood. Faster and faster I have heard said.

  11. Both invests could be arguably named by morning. What will the NHC do? Each satellite update closer to classification for both.

    1. Looks OK to me. But this site really needs to use another comment system – even Disqus would be much better. There’s no indication that someone is replying, and no auto-display of new comments. Very disappointing.

      1. If you know the whole story, science got decapitated. Pretty much across the board. YCC gave Jeff and Bob, the good Docs, a place they can still broadcast the truth. We should be happy. It’s Yale right? Being so, they’ll get this rolling right soon.

  12. Japan Meteorological Agency
    Tropical Cyclone Advisory #27 – 9:00 AM JST August 31 2020
    TYPHOON MAYSAK (T2009)
    =================================================
    Sea South of Okinawa

    At 0:00 AM UTC, Typhoon Maysak (955 hPa) located at 22.4N 128.4E has 10 minute sustained winds of 80 knots with gusts of 115 knots. The cyclone is reported as moving north at 15 knots.

    Storm Force Winds
    ===================
    80 nm from the center

    Gale Force Winds
    ===================
    300 nm from the center in southern quadrant
    240 nm from the center in northern quadrant

    Dvorak Intensity: T5.5-

    Forecast and Intensity
    =======================
    24 HRS: 26.7N 126.1E – 95 knots (CAT 4/Very Strong Typhoon) 80 km west northwest of Kume Island (Okinawa Prefecture)
    48 HRS: 29.9N 126.5E – 95 knots (CAT 4/Very Strong Typhoon) East China Sea
    72 HRS: 37.2N 129.2E – 70 knots (CAT 3/Strong Typhoon) Over land Korean Peninsula (South Korea)

      1. interesting how they do the linear interpolation of the cone compared to the smoothed cone here (nothing wrong with that, a human can figure it out)

  13. This is wrong. If we in the United States choose to continue the use of plastics, particularly single-use plastic – then we need to find a way to clean it up our own selves instead of dumping it on any other country. If making a profit off of recycling or getting rid of it is a problem, then maybe the real probl;em is the plastic itself. https://www.nytimes.com/2020/08/30/climate/oil-kenya-africa-plastics-trade.html?action=click&module=Top%20Stories&pgtype=Homepage

    According to documents reviewed by The New York Times, an industry group representing the world’s largest chemical makers and fossil fuel companies is lobbying to influence United States trade negotiations with Kenya, one of Africa’s biggest economies, to reverse its strict limits on plastics — including a tough plastic-bag ban. It is also pressing for Kenya to continue importing foreign plastic garbage, a practice it has pledged to limit.
    Plastics makers are looking well beyond Kenya’s borders. “We anticipate that Kenya could serve in the future as a hub for supplying U.S.-made chemicals and plastics to other markets in Africa through this trade agreement,” Ed Brzytwa, the director of international trade for the American Chemistry Council, wrote in an April 28 letter to the Office of the United States Trade Representative.
    The United States and Kenya are in the midst of trade negotiations and the Kenyan president, Uhuru Kenyatta, has made clear he is eager to strike a deal. But the behind-the-scenes lobbying by the petroleum companies has spread concern among environmental groups in Kenya and beyond that have been working to reduce both plastic use and waste.

    1. We (the consumer) did not ever ‘choose’ plastics. They were dreamed up and invented by “scientists” from university trained chemical engineers in the employ of the oil conglomerates.
      Food tastes better in glass containers. Is not toxified and glass is 100 percent renewable.
      But re whiny pseudo ecologists, you continue to purchase products in plastics, so you are a part of the problem.
      Stop looking for laws to force the change you claim to believe in…BE THE CHANGE FIRST or shutty!

      1. I agree with you, plastic was shoved out to consumers – but now there is virtually nothing you can buy that isn’t wrapped in plastic. You can be an army of one not buying it – good luck.

        And sad to say, the BEST result is that this wrap plastic ends up in the landfill. The bags that stuff comes in everywhere, becomes an even bigger problem when we attempt to recycle it, or as people often do, just chuck it as litter. – see how
        supposedly “recycled” plastic just gets burned in indonesia to make tofu. We are dealing with professional liars here.

        While walking my kid’s mom’s dog today, I was astonished at the sheer amount and variety of plastic crap that is everywhere on the sidewalks and streets here.

        Is it any wonder that a good portion of all these little pieces of plastic (at least where I live) and up in the pacific ocean?

        We are just too irresponsible, and in so many ways – we 5h1+ where we eat.

      2. And since you can’t buy milk or … anything … in a glass bottle anymore … we’re just supposed to shutty?

        I sense the sentiment that is trying to be conveyed here, but am not sure this was the right way to apply the concept. You don’t have a consumer choice to buy liquids in glass bottles anymore, for decades now. It isn’t even there to choose. So, I guess we just got told to shutty.

        And plastic toxicity and pollution isn’t a belief, there’s science and evidence there to follow. I can’t tell if this was comment from HsdarAbit was trolling, or trying to be sort of helpful and just kind of missing by a little bit?

  14. SpaceX rocket just launched. Too many clouds for a picture. Clouds did trap and roll the sound better. Really long, loud and booming sounding.

  15. We don’t have the bat signal, but we should have the blob signal. Hurricane Season without Grothar Captaining the ship just does not feel right. First Mate Patrap somewhere posting a we’re gonna need a bigger boat meme.

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