Forgot your password?
typodupeerror
Earth NASA Science

Hurricane Sandy a 1-in-700-Year Event Says NASA Study 148

Posted by timothy
from the nothing-to-see-here dept.
Rebecka writes "Hurricane Sandy, which pelted multiple states in Oct. and created billions of dollars in damage, was a freak occurrence and not an indication of future weather patterns, according to NASA's Goddard Institute for Space Studies via LiveScience. The study (abstract), which calculated a statistical analysis of the storm's trajectory and monitored climate changes' influences on hurricane tracks, claims that the tropical storm was merely a 1-in-700-year event. 'The particular shape of Sandy's trajectory is very peculiar, and that's very rare, on the order of once every 700 years,' said senior scientist at NASA and study co-author, Timothy Hall. According to Hall, the extreme flooding associated with the storm was also due to the storm's trajectory which was described as being 'near perpendicular.' The storm's unusual track was found to have been caused by a high tides associated with a full moon and high pressure that forced the storm to move off the coast of the Western North Atlantic."
This discussion has been archived. No new comments can be posted.

Hurricane Sandy a 1-in-700-Year Event Says NASA Study

Comments Filter:
  • by ackthpt (218170) on Tuesday July 16, 2013 @12:18PM (#44299073) Homepage Journal

    ... is that it is possible to flip a coin and have it land heads up 1,000 times consecutively - it can happen and is increasingly likely to happen in a larger number of trials. Same can be said for a "Sandy" occurring in consecutive (or near neighbor) years. One thing is evident - the east coast, sand bars, outer banks, etc, were formed and shaped by this type of storm. I expect the 700 year estimate is fanciful.

    • Re: (Score:3, Informative)

      by alen (225700)

      Sandy hit at high tide and a full moon
      the gravity of the moon raised the water a few feet which is why the storm surge caused all the flooding

      we had a more powerful storm hit NYC the year before and it did a lot less damage because it didn't hit at high tide. very minor flooding.

      for another hurricane to do as much damage as Sandy, it has to hit the around the 22nd of the month and make landfall close to 8pm

      • by Jawnn (445279)

        Sandy hit at high tide and a full moon the gravity of the moon raised the water a few feet which is why the storm surge caused all the flooding

        we had a more powerful storm hit NYC the year before and it did a lot less damage because it didn't hit at high tide. very minor flooding.

        for another hurricane to do as much damage as Sandy, it has to hit the around the 22nd of the month and make landfall close to 8pm

        ...and be at least as strong. I know it's convenient to leave out meaningful factors that don't really support your assertion, but the force of the storm kinda counts, don't you think?

        • Re: (Score:2, Insightful)

          by alen (225700)

          sandy was barely a category 1 hurricane, very weak

          • Re: (Score:3, Insightful)

            by p.rican (643452)
            Wrong.

            It was a Category 1 Hurricane with Category 2 damage. It hit at high tide with a full moon and it met up with another storm system that was already over the northeast. Take a ride around NJ or the south shore of Long Island or Staten Island and tell me again that it was weak. Also remember that most of the people affected JUST got their homes/lives straigthened out from Irene 13 months prior.

      • by chipschap (1444407) on Tuesday July 16, 2013 @03:35PM (#44302007)

        This is not the politically correct answer. You are supposed to blame Sandy on global warming.

        Mind you, that may be the scientifically correct answer too. I certainly don't have the background to make that judgment. And I am definitely not a global warming naysayer by any means.

        But if you publish a study saying Sandy was due only to various things other than global warming, I think you're in politically dangerous territory, even if the study is an honest one.

        Of course, this defines the problem. When science is politicized, no good comes of it.

        • by cellocgw (617879)

          No, the politically correct answer is to blame Sandy on Obamacare.
          I liked it better when the stock culprit was "all them nucular power plants."

      • it has to hit the around the 22nd of the month and make landfall close to 8pm

        That would be valid only for this month, as the tides don't follow a monthly cycle but a ~ 28-day cycle.

      • by bobbutts (927504) <bobbutts@gmail.com> on Tuesday July 16, 2013 @04:16PM (#44302461)
        Check out IKE (Integrated Kinetic Energy). It is a valuable metric for quantifying potential for storm surge. Sandy was freakishly high on this scale.

        This article
        Superstorm Sandy packed more total energy than Hurricane Katrina at landfall [washingtonpost.com]
        does a good job explaining.

        Long story short, discount Saffir-Simpson categories and look at IKE when you want to discuss surge.
      • > Sandy hit at high tide and a full moon

        *AND* there was a big fat blocking high sitting in the Atlantic, blocking the standard north-eastward track a post-tropical storm usually takes, forcing it westward. That's 3 independandant variables that had to coincide just so. It was a case of extreme bad luck.

    • by MightyYar (622222)

      The entire East Coast does not have the same probability of getting hit by a hurricane. The Outer Banks get nailed almost every decade. The Jersey shore? The chance of getting hit each season is approximately 1 in 200. That said, one hit in 1903 and another in 1944. Then you have Sandy. So over the last 100 years, it looks more like once every 40-60 years (based on a whole 3 data points). Check out the risk maps. [globaldatavault.com]

    • Re: (Score:2, Funny)

      by fustakrakich (1673220)

      You know, 700 years ago the Indians were burning lots of fires to send smoke signals. Obviously they caused a climate change that brought the "Sandy" like hurricanes to their shores back then.

      Anyway, it's all bullshit. Everybody knows that hurricanes are caused by gays who want to marry horses, or Protestants, take your pick [mcgill.ca]...

      • by ackthpt (218170)

        You know, 700 years ago the Indians were burning lots of fires to send smoke signals. Obviously they caused a climate change that brought the "Sandy" like hurricanes to their shores back then.

        Somewhere around 13,000 years ago the last glacial age ended, in effect the Earth has been warming prior and is accelerating today, which means weather patterns are changing. To mark 1 in 700 seems almost casually to overlook this relatively short time span and what has transpired within.

    • You aren't understanding where they came up with this statistic. Each of the inputs that make this storm unique are their own 'dice'... these probabilities are then combined to estimate the probability of another storm like Sandy will occur- once every 700 years.
      What is the problem again? And why would it be increasingly likely?

    • Remember also, it's only talking about the precise trajectory, not the size of the hurricane. You could have another hurricane that is larger, and more destructive, that wouldn't match this "1 in 700" event because the path of the hurricane is different.
    • by memnock (466995)

      What is NASA gonna say if another 'Sandy' hits again... in the next 5 years? No, I'm not predicting there will be one within 5 years. I'm just wondering what they'd do if it did occur very soon?

  • by tekrat (242117) on Tuesday July 16, 2013 @12:21PM (#44299115) Homepage Journal

    That's funny because the year BEFORE Sandy, we had a "Once in a Hundred Year Storm" hit the northeast. And then next year, the exact same thing happened again, but it was worse.

    And this year, I expect the weatherman to say the exact same thing....

    • by MightyYar (622222) on Tuesday July 16, 2013 @12:26PM (#44299197)

      You are conflating what NASA said with something your local weatherman may have said.

      • Perhaps... but these "Once in a $TIMEPERIOD" storms are so frequent in the news, the saying has lost credibility. When the northeast gets pounded that often and we hear that phrase every time, one wonders what the purpose of saying the phrase is. Is it an excuse? Or is there something we should be doing to the northeast? Moving people out? Putting up better defenses? Allocating more money for repair?
        • by MightyYar (622222)

          I'm not sure what you mean by "the Northeast". That's a really big region, with some parts susceptible to hurricanes and some not. Sandy was the first real strike on most of the New Jersey coast since 1944, for instance. It was also a colossal storm - the largest recorded if memory serves. The year before, there was Irene which hit Coney Island. While there were overlapping areas of damage, for the most part Irene caused flooding to inland areas, whereas Sandy really punched coastal areas. Irene barely scra

    • by Culture20 (968837)
      I'm guessing you weren't around for any cicada brood conjunctions.
    • by SJHillman (1966756) on Tuesday July 16, 2013 @12:40PM (#44299431)

      If there's 100 different low probability events, then there's a decent chance of any two of those happening in consecutive years. Unless there's some correlation between the two that makes them unlikely to happen together, it's no more special than any other coincidence.

      • I think you made another and possibly more important point without stating it: if there are 100 low probability events, there's a high probability of a catastrophe happening in any given year.
    • by alen (225700)

      hurricane irene was not a once in a 100 year storm, not even close

    • by alen (225700)

      not only was Irene not a power storm, in NY state it did the most damage after it lost hurricane strength. it was a slow moving storm and dumped a lot of rain in westchester county washing out a lot of railroad tracks

    • by samkass (174571)

      That's funny because the year BEFORE Sandy, we had a "Once in a Hundred Year Storm" hit the northeast. And then next year, the exact same thing happened again, but it was worse.

      And this year, I expect the weatherman to say the exact same thing....

      Irene was indeed as powerful as Sandy and happened only one year previous, but not as big a storm area-wise, and did not hit perpendicular on a full moon at high tide. Thus, it did relatively minor damage.

      • by c0d3g33k (102699)

        That depends on where you were and what you consider damage. Irene was much worse here in Connecticut in terms of wind effects (downed trees on roads/houses/etc) than Sandy. Several hours later as the storm moved north, flooding in southern Vermont was horrible and the effects still being felt 2 years later.

        The wind effects were exacerbated by the fact that Irene hit in August - late summer - when trees and plants had full foliage. Lots of trees came down as a result - if you were lucky they didn't fall

        • Personally, in my NJ suburban area Sandy hit us a lot worse than either Irene or that freak snow storm around Halloween 2011.

          I don't remember much about Irene actually. I think we were without power at my parents house for like a 2-3 days but some co-workers were pushing a week. Some were without water, but in my case I was just mildly inconvenienced. And gas wasn't that hard to find.

          A few months later we had the freak snow storm around Halloween. The leaves were still on the trees due to a mild autumn

        • by ThosLives (686517)

          The fact that the storm was larger in area and impacted regions with higher population density and correspondingly greater economic devastation was what made it newsworthy.

          Indeed - I wish that, instead of just saying "most expensive storm ever!" they would normalize it somehow - perhaps to something like cost relative to annual mean salary per unit population density. This way you'd weed out all the effects of inflation and higher concentrations of development.

          Perhaps mean salary isn't the correct metric -

      • by p.rican (643452)
        Irene dropped approximately 10 inches of rain in less than 24 hours. Sandy dropped approximately 2 inches of rain in less than 24 hours. The full moon, high tide and meeting up with another storm system in the northeast is what killed us. A lot oif things went "right" for it to become a super storm
    • by kimvette (919543)

      I think you misunderstand what the 10, 50, and 100 year storms refer to.

  • So, if we get another one like these in our lifetime, what then?

    NASA just says oops and people keep pretending like there isn't climate change happening?

    • by alen (225700)

      if you look at wikipedia, NYC gets hit by Category 3 storms once every 70 years on average. Sandy was barely a Cat 1 when it hit us.

      the last one was in 1938. 135 mph winds when the storm made landfall at Long Island. we are actually overdue for a very powerful storm here

      • The entire US is overdue for a Category 3, not just New York.

        A quick google search...
        http://images.google.com/search?site=&tbm=isch&q=category+3+landfall+USA [google.com]

        http://4.bp.blogspot.com/-bJhUmJyxrQs/ULy7NL1QbAI/AAAAAAAACQw/RlSJLqrsz5Y/s1600/hurrdrou0613.jpg [blogspot.com]

        looks promising.

        Anyway. Pretty obv been awfully lucky recently.

      • by Shinobi (19308)

        "Sandy was barely a Cat 1 when it hit us."

        True, if you look at it in a very simplistic fashion, i.e wind speed only. However, if you look at it in terms of size, Sandy was a MONSTER, and it hit in conjunction with another weather system of hard weather.

        The total energy potential of Sandy, due to sheer size, was greater than quite a few Cat 3's etc.

        • As I recall Sandy was a tropical storm when it hit.

          Found a pic of Sandy
          http://en.es-static.us/upl/2012/10/Hurricane-Sandy-on-October-29-2012.jpg [es-static.us]
          Compared to...

          https://upload.wikimedia.org/wikipedia/commons/thumb/8/81/Tropical_storm_irene_aug_27_2011_at_1059_est.jpg/932px-Tropical_storm_irene_aug_27_2011_at_1059_est.jpg [wikimedia.org]

          The size doesn't seem that dramatic.

          So. Not sure what the monster part was. Apart from, ofc, the fact that it hit at an unusually high tide.

          I believe most of the damage was storm surge, not du

          • Erm. Right. Point of pic, really, was that as hurricanes fall apart into tropical storms, they are almost always huge things that cover like most of the east coast.

            Compared to pics of hurricanes falling apart into a tropical storm as they track up the coast that I recall and could find of the past, Sandy seems pretty typical.

            The dramatic part was the high tide and pushing that storm surge up against New York City which was woefully unprepared despite warnings in the past (shades of Katrina).

          • by Shinobi (19308)

            Seriously, look at those pics again... And compare the scale of the pictures themselves... Then you'll see that Sandy absolutely dwarfed Irene... Hint: In the Sandy pic, the scale is such that you see a sizeable portion of Florida.. The Irene pic, you have the Norfolk area as the southernmost part...

            • http://m8y.org/tmp/temp.jpeg [m8y.org]

              A rough approximation of shapes, as near as I can make out from landmarks.
              Sandy is larger, but, doesn't seem to be that much larger to me.

              And, as noted in comment to AC, my experience of Sandy in maryland was *very* different from that of people in NJ and NY (as in, barely felt like a tropical storm in the impact on our counties in terms of power loss and damage).

              • I guess I should say, didn't even feel like a...

                Anyway. Sandy was definitely spread over a large area, which helped diffuse it further.
                You can talk about total energy, but if the storm is spread over the entire continent, it isn't very interesting.

                Most places make clear the storm surge was the worst damage, and that would certainly have been helped by having been spread out, while, the results inland would have been significantly less.

                The need for storm surge protection for New York City had been known for

    • People who constantly blame everything on climate change - even events like hurricanes, where there is no scientific consensus on the matter - are as big a problem as the "I don't believe in global warming" crowd.

      • Re: (Score:2, Informative)

        by gstoddart (321705)

        even events like hurricanes, where there is no scientific consensus on the matter - are as big a problem as the "I don't believe in global warming" crowd.

        Well, the problem with that statement is that except for the "I do not believe in global warming" crowd, there's an awful lot of scientific [nasa.gov] consensus [ca.gov] on the topic.

      • Agreed. One of the other posters pointed out that Sandy did as much damage as it did in part because of the effect of the moon and the tides. Now, I'm no climate scientist, but I was completely unaware that global warming was affecting the moon's gravitational pull.

      • Anecdotally speaking, I think that meteorological records are being broken at an unprecedented historical level. Just what I've noticed, and I have been fooled by evidence in the past.

    • Then we had some bad luck. Or God hates us. You pick.

        You can't mitigate every single potential risk, you have to look at the odds of a given risk occurring and prioritize response based on that.

    • by icebike (68054)

      Maybe you should visit the source, NASA's Goddard Institute for Space Studies http://www.giss.nasa.gov/ [nasa.gov] and see if you think this particular branch of NASA is soft pedaling global warming.

      It's been James E. Hansen personal pulpit for the last 30 years.

    • by JWW (79176)

      I have to commend GISS on this analysis. I would be to their advantage to say:

      Climate Change Caused Hurricane Sandy!!!

      But they took the data, and analyzed it and came to a scientifically sound conclusion that it was not purely a Climate Change caused event.

      This is exactly how things should be done.

      Also, the next time people get all up in arms saying:

      This huge cold weather snap is proof against Climate Change!!

      GISS can study that too and prove that no, the cold snap in one particular large region has nothin

    • by bill_mcgonigle (4333) * on Tuesday July 16, 2013 @12:44PM (#44299525) Homepage Journal

      So, if we get another one like these in our lifetime, what then? NASA just says oops and people keep pretending like there isn't climate change happening?

      One supposes that with new data the NASA scientists would revise their theories. If NASA's models are broken, then attack the models. Short of that, data-less speculation is just that.

    • by stenvar (2789879)

      These estimates are not based on counting the number of storms that actually occur, they are based on simulations of storm paths.

      The probability that another one of these happens in our lifetime is about 10%.

      The probability that another once-in-700-year event happens somewhere in the US even just next year is nearly 100%, since there are many more than 700 sites that keep and report these statistics. In different words, you expect multiple extreme weather events to be reported in the US every year.

      Does that

  • Does that take into account that the weather has changed due to climate change (global warming) and these rare events will become more probable in this new climate?
  • After massive pressure from Congresspersons responsible for NASA's budget, NASA said, "Hurricane Sandy, which pelted multiple states in Oct. and created billions of dollars in damage, was a freak occurrence and not an indication of future weather patterns..."

    TFTFY.
  • Those evil climate change deniers at NASA are up to their old tricks again!

  • On the other hand, natural disasters that make those who want to cut disaster relief look like hearless fools right before a presidental election are a 1-in-4 year event.
  • 700 years seems oddly specific. I wonder how that was worked out. It isn't like we have any real reliable date past say 100 years for example. How are they extrapolating 700 years statistically?

  • by gmuslera (3436) on Tuesday July 16, 2013 @12:53PM (#44299677) Homepage Journal
    Lets not fall into the Gambler's fallacy [wikipedia.org], it don't mean that won't happen next year, and the next after it, or that should happen for sure in the next 700, 1000, or 10000 years. Also, odds of taking a certain, specific path are pretty low, as the odds of hitting a particular point of a dartboard, but that don't mean that no point of the dartboard will be hit, and the same for potential paths of destruction.
    • ...not to mention what they are predicting- Sandy was hardly considered a category 1 hurricane when it hit, but it was very large and came ashore at an odd angle.

      Smaller much more powerful (higher winds) storms have hit the coast in the last century.

    • by Sir Holo (531007)

      Lets not fall into the Gambler's fallacy [wikipedia.org].

      Yes. And add to that that the earth's atmospheric-oceanic system is not currently in a steady state (with unchanging boundary conditions or unchanging time-averaged conditions), and the idea of any XXX-year storm becomes even less useful.

  • if it happens every 700 years then how can we blame global warming?

    I think the key is if 1 in 700 year events start happening every second Tuesday, then I might be convinced.

  • by gweihir (88907) on Tuesday July 16, 2013 @01:34PM (#44300367)

    These records get broken as a matter of routine these days in exactly the way climate sciences has predicted for quite a while now: Things get more extreme and less stable is the main prediction. So while Sandy may have been once in 700 years for the past, it could well be 1 in 50 years or even worse in the future.

    • by iggymanz (596061)

      Utter nonsense, no records broken at all by storms on historic scale. No evidence of more frequent nor more powerful tornadoes, hurricanes, floods, droughts nor anything else. The worst storms and droughts have not occurred in the past decade, that's a fact.

      • by gweihir (88907)

        Keep telling yourself that....

      • Re: (Score:2, Informative)

        by Anonymous Coward

        Le sigh.

        From a recent WMO report [wmo.int] titled "2001-2010, A Decade of Climate Extremes":

        Every year of the decade except 2008 was among the 10 warmest years on record.

        The 2001-2010 decade was the second wettest since 1901. Globally, 2010 was the wettest year since the start of instrumental records.

        According to the U.S. National Oceanic and Atmospheric Administration, 2001-2010 was the most active decade since 1855 in terms of tropical cyclone activity in the North Atlantic Basin.

        According to the 2011 Global Assess

  • by wcrowe (94389) on Tuesday July 16, 2013 @02:38PM (#44301267)

    Yeah, but to paraphrase Terry Pratchett, everyone knows that a 1 in 700 year chance occurs nine times out of ten.

    • by Z00L00K (682162)

      And 1 in 700 is the statistical figure, you can have one every year for 10 years and then no serious storms for the next 7000 years.

      What is important is to realize that humans don't have much to put up against nature when it's doing the worst it can. The only thing to do is to be prepared for bad events. Construct a survival kit that you can use when the time comes. At least if you live in an area where nature can make a serious impact.

  • How useful is this to know? It's not like New York is now definitely safe from hurricanes for the next 700 years.
  • by petaflop (682818) on Tuesday July 16, 2013 @03:54PM (#44302235)

    The NASA paper does not say that Sandy was not influenced by climate change. What they actually calculate is that Sandy-like hurricanes occur once in 700 years under pre-industrial conditions. Here is one of many relevant quotes:

    The fact that our calculations show Sandy’s track to be so rare under long-term average climate conditions lends support to a climate-change influence. On the other hand, the most recent climate model simulations project reductions in blocking frequency in a warmer climate [Dunn-Sigouin and Son, 2012]. Global high-resolution models suggest that tropical cyclone frequency will decrease globally, while mean intensity will increase. There is growing consensus that the most intense events will increase in frequency, but there is high uncertainty, especially in individual basins [Knutson et al., 2010]. On the other hand, further sea level rise is almost certain, with a meter or more expected in the next century [Nicholls and Cazenave, 2010]. This will exacerbate TC-induced flooding even if the storms themselves do not change.

    Someone should have RTFA.

  • ...as a claim that storms as damaging as Sandy occur in this area with only a 1-in-700-year probability. As the article says, however, this was an unusual storm in a number of ways, and a more conventional storm causing at least as much damage is more probable than a repeat of Sandy.

  • We have such an opportunity to expand our vocabulary - new words, like haboob, and dericho.

  • by khallow (566160) on Tuesday July 16, 2013 @05:13PM (#44303211)
    First, the research extrapolates to a 700 year period from data that at best can be considered to cover 150 years. Of that period we have well defined hurricane tracks for perhaps 80 years. And it's only with meteorological satellites in the past 40 or so years that we've seen hurricanes from birth to death. There are plenty of stochastic models that will give you whatever outcome you desire.

    Hurricanes with Sandy's characteristics may have always been, for example, 1 in a century hurricanes due to dynamics that the stochastic model above completely fails to anticipate. But we had so little data that this is the first one we have seen with these characteristics.

    Second, we are ignoring the consequences of observation bias. Given the many hurricanes that have happened, I bet we'll find that most have tracks that would be similarly infrequent. Consider the case of flipping a fair coin ten times. No matter what the outcome of heads and tails in sequence, it will be a 1 in 1,024 event. There are a fair number of hurricanes that hit the mid-Atlantic states. Each one may take an infrequent path. I see nothing unusual in hurricane Sandy being rare or for that matter not particularly rare.
  • I would like to point out that NASA considers a quantitative risk assessment to be a +/- order of magnitude tool. So if the actual frequency turns out to be within 70-7000 years, the QRA is as acceptable.
  • ... really, _700 years_ of records? And the margin of error on those early 'records' would be? And the margins of error on your model's assumptions would be? Oh, and did all your models agree on this or were they in agreement +/- some margin?

    Vague hand waving at best, attempt to placate/influence at worst.

    What should have been said, "We _guess_ that _maybe_ it was a 1 in 700 hundred-ish year-ish event. But that could be totally wrong. Thanks for listening."

"Why can't we ever attempt to solve a problem in this country without having a 'War' on it?" -- Rich Thomson, talk.politics.misc

Working...