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Hurricane Humberto Ties Atlantic Record

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Tropical Storm Humberto on Sept. 10, 2013.

Since 1941 we have never gone later than Sept. 11 without a hurricane forming in the Atlantic Ocean. So when the National Hurricane Center upgraded Tropical Storm Humberto to a hurricane early Wednesday morning, Humberto tied the Sept. 11 record set by Hurricane Gustav in 2002. Gustav later struck North Carolina. Humberto is currently in the tropics between Africa and the Caribbean and is forecast to drift around in the mid-Atlantic, not making landfall.

This year’s record is odd, however, because conditions in the Atlantic have been ripe for storms.

Usually, fewer hurricanes form in the Atlantic when El Niño conditions are present in the Pacific Ocean, because they tend to set up weather patterns that cause shearing winds over the Atlantic that can cut down tropical storms as they grow. Cool Atlantic water also undermines hurricanes. But 2013 is not an El Niño year and water temperatures have been above average, so more storms should have formed by now. On average, three hurricanes coalesce in the Atlantic by Sept. 9. A typical season, which runs from June 1 to November 30, produces six hurricanes, two of which are strong.

It’s impossible to tell how much water, sun and wind energy exists during the entire six-month season to fuel big storms. Meteorologists use the “accumulated cyclone energy” index as a proxy. ACE is the square of wind speed recorded every six hours in every storm with at least 40 mph sustained winds. Over the past 20 years, ACE has averaged 50 units through Sept. 9, but this year the total was just 9.6 units, according to Jeff Masters, a meteorologist who runs, a Web site that analyzes and tracks severe weather in great detail. Also strange.

The main reason for the calm, according to Masters, has been a large amount of dry, stable air over the Atlantic, providing less moisture and energy to mounting storms. Much of that air has wafted out over the ocean from the Sahara Desert in Africa. Most Atlantic hurricanes begin as small atmospheric disturbances off the coast of Africa that strengthen as they work their way west and north.

A slow first half of hurricane season is not unusual, however, and it has no bearing on what might happen through the end of November. At least four and as many as nine hurricanes have formed in each of the five years since the 1960s that did not have a hurricane by the end of August. Superstorm Sandy struck the U.S. on Oct. 29 last year. More than 60 percent of Atlantic cyclones form during the second half of the period, so the peak time is just approaching.

As Masters points out on his blog, “the season with the greatest similarity to what we’ve seen during the first half of the 2013 season was 1988. That year, we also had unusual quietness before September 10, no El Niño, and above average ocean temperatures in the [Atlantic zone where hurricanes form]. But [then] the most powerful Atlantic hurricane ever recorded up to that time ripped through the Caribbean, Hurricane Gilbert, as well as two other major hurricanes.”

And as forecasters at the National Weather Service often say, it only takes one bad storm hitting land to make a bad season.

By the way, in 1941 the date for the first hurricane is Sept. 16, but it may be hard to say how conclusive that record and earlier ones are. The famous Hurricane Hunters began systematically flying over the Atlantic in 1944, and satellite surveillance began in 1960.

Image courtesy of NOAA

Mark Fischetti About the Author: Mark Fischetti is a senior editor at Scientific American who covers energy, environment and sustainability issues. Follow on Twitter @markfischetti.

The views expressed are those of the author and are not necessarily those of Scientific American.

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  1. 1. ErnestPayne 2:43 pm 09/11/2013

    Obviously “global warming” is a myth or so you will be told. Frankly I am delighted not to have a major hurricane season so far into the year. BTW “global warming” is happening. It is just not happening on a steady basis.

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  2. 2. Carlyle 4:57 pm 09/11/2013

    It does not matter how many billions the climate forecasters spend on some of the most powerful computers in the world, while ever they are programmed with models designed to give the outcomes the AGW adherents long for & with manipulated or selective data, they will continue to get egg on their faces.

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  3. 3. Bodhi37 1:04 am 09/12/2013

    Oh, and of course you have a evidence that these models are programmed in this way Carlyle. I have seen posts like yours for years ever making such claims without a shred of evidence because of course there is none. The most absurd that I can’t help but laugh at are the ones that claim a conspiracy of course with no evidence. These trolls seem to exist only to make disparaging comments often in caps which of course is equilivant to screaming. In addition they usually avoid any substantive discussion on what that article actually is about. And of course the simple reason is because they can’t. They are driven by they ideology and thus they are controlled by their emotional reactivity to whatever they disagree with. The reality of global warming is not going away so neither will this dispute. It is really kind of a surreal controversy given how their deniers are completely outclassed by the science which they try to compensate for by their shrill arguments.

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  4. 4. Carlyle 8:19 am 09/12/2013

    Yes. Australia’s CSIRO & BOM organisations, both Government funded have for years selectively chosen data to give alarmist results then used the same data to make forecasts about heat waves, droughts & floods that have been wrong. Britain’s weather service & the US services have also repeatedly made appalling predictions that have failed miserably despite their massive budgets. People like you dismiss the evidence such as that contained in the email scandal then claim there is no evidence.

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  5. 5. rkipling 1:26 pm 09/12/2013

    An interesting study.

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  6. 6. sault 6:50 pm 09/12/2013


    It’s interesting that you didn’t mention this snippet of it:

    “Another possible driver of the difference between observed and simulated global warming is increasing stratospheric aerosol concentrations. Results from several independent datasets show that stratospheric aerosol abundance has increased since the late 1990s, owing to a series of comparatively small tropical volcanic eruptions8. Although none of the CMIP5 simulations take this into account, two independent sets of model simulations estimate that increasing stratospheric aerosols have had a surface cooling impact of about 0.07 °C per decade since 19988,9. If the CMIP5 models had accounted for increasing stratospheric aerosol, and had responded with the same surface cooling impact, the simulations and observations would be in closer agreement. Other factors that contribute to the discrepancy could include a missing decrease in stratospheric water vapour10″

    BTW, the decrease in stratospheric water vapor accounts for 25% of the “slowdown” in global warming:

    Thanks for providing the link, but it does not support the climate denier position in any way.

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  7. 7. sault 6:52 pm 09/12/2013

    LOL…climate science deniers think one year is all it takes to make a trend…Silly deniers, I guess facts are for people who leave in the really real world and not your polluter-funded fantasy land.

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  8. 8. Carlyle 4:31 am 09/13/2013

    Which of the last 15 or 16 years of no warming above long term historic trend are you cherry picking now?

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  9. 9. rkipling 11:50 am 09/13/2013

    To comment readers,

    Some of us are motivated to occasionally post comments intended to advance the discussion. The British study above is one of those. I’m sure you notice that it was described only as “interesting” and wasn’t characterized otherwise.

    This paper simply reports that actual global mean surface temperature hasn’t risen as much as some climate models predicted. It doesn’t say temperatures aren’t rising. It doesn’t say AGW isn’t happening. It just reports that actual temperature rise is less than half the predicted value. Then it goes on to suggest how models might be improved. Most people would see value in more accurate climate models and wouldn’t see them as deviation from dogma.

    That’s how most people would understand it. But as you see among the commenters here, there are zealots to whom the current climate models are Sacred Computer Programs (I envision the boot screen with cherubs and an angelic chorus .wma file.) I’m puzzled by this. Isn’t improved simulation accuracy a good thing?

    You know on second thought, I’m probably unfair when I accuse them of being as adverse to change as the Roman Inquisition of 1633 (Those guys back then were really stuck on stupid.) Had the models underestimated the actual temperature increase, they would be falling over each other to adopt the “improved” model version.

    It may take some picking through, but I think you will find the occasional valuable comment here.

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  10. 10. Carlyle 1:28 pm 09/13/2013

    The fundamental flaw that will haunt AGW adherents is their demonisation of CO2. The evidence that it is NOT causing discernable global warming has been abundant for years. The attempt to continue this demonisation is leading to a frantic hunt for excuses. Meanwhile research into better understanding climate has been stymied by the CO2 obsession. Research done on the influence of the sun & cosmic rays for example is trivialised & thus discouraged. Climate science has been politicised in the same way the Stalin era politicised botany leading the Soviet Union to disastrous agricultural decisions that caused famine. Get politics out of science & get back to scientific rigour.

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