Almost every time NWS issues a blizzard warning for my area (Southern Maine), CNN talks about “the storm of the century” hitting New England. This happens about once every year or two. The last time I checked, a century was 100 years.
Actually that sounds like they are talking about this century–the 21st century–rather than a 100 year period.
With reference to this type language I am quite surprised how often we have been having 100 year floods.
There are a couple reasons why this happens. 1) CNN is lying/exaggerating. 2) You’re misremembering that it happens every year. 3) A 100-year storm does not mean it happens every 100 years, only that it has a 1% chance of happening in a given year. It’s perfectly possible for a 100 year storm to happen in consecutive years or even multiple times in a year. 4) Climate has changed how much snowfall should constitute what a 100-year storm is, but that definition lags reality.
Actually, yes, a century isn’t exactly the same length it used to be, because the earth’s orbit is not absolutely stable. The length of the day is also slightly varying.
I remember when there was a Sale of the Century every night.
If this year’s storm is the biggest in a century, then it would seem reasonable to call it the storm of the century, even if two years ago there a was a smaller storm that was, at the time, the storm of the century by the same definition. To be accurate, they should say, “It’s the storm of the century up to and including this year. Next year may be worse though. We hope so. It’s fun sending roving reporters out into the insanely dangerous streets. It just never gets old.”
For the 100 year floods, I don’t quite get that either. Yes, technically it means a 1% chance of it happening in a year. However, the size often seems to be fixed, and the frequency allowed to vary to take into account changing conditions. There’s a certain logic to that I guess, but it makes the naming confusing. A hundred year flood might have been an accurate name for the 20th century, but now it’s going to hit every decade or so (and dropping). Maybe they should start ranking floods by categories, like they do with hurricanes.
News agencies operate under the assumption that people won’t pay attention to mundane things. So they over-use superlatives to give the impression that the upcoming event is unprecedented. The problem with this is that they are correct about people’s expectations, and real dangers can be ignored.
The x-year storm is based on probability, and has a specific meaning for engineers. When designing a structure, the forces due to wind, flood, snow, etc., are determined by the maximum of each of these parameters that can be expected during the “design” storm. Building codes specify wind speeds, flood depths, snow loads, etc., based on the size of a storm that has a probability of occurring once every x number of years. The value for x varies based on the importance of the structure and the projected cost of repair if the loads exceed the design values. For example, a warehouse might be designed for loads associated with a 25 year storm, and an apartment building might be designed for a 100 year storm. BTW the value of human life is indirectly factored into this. Higher occupancy buildings are assigned higher importance factors, and schools for younger children have higher importance factors than those for colleges. The codes are updated every few years to account for new research and new historical data.
Yeah, like others commented, CNN and other media needs to put what is going on in the context of the changes that are going in the climate.
Another thing that has been found recently is that the increase in water vapor and a warming arctic is also making intense snow storms that are more persistent thanks also to weather patterns that are getting stuck.
I don’t see the debate, here.
It is not really a rant, so I won’t send it to The BBQ Pit and it is not really a General Question, so I guess it is going to IMHO.
Just give Linoge what he wants and he’ll go away!
Are you also surprised at how often scientists keep bringing up the issues of climate change and rising sea levels? :rolleyes:
More seriously, the term “100-year flood” or “100-year storm” is a hydrological term that is based on the “design storm” which is itself based on historical averages.
A “2-year storm” indicates a storm of sufficient intensity that it is 50% likely to occur in any given year, based on historical averages.
A “10-year storm” indicates a storm of greater intensity such that it is 10% likely to occur in any given year, based on historical averages.
A “100-year storm” indicates a storm of still greater intensity such that it is 1% likely to occur in any given year, based on historical averages.
Property that is flooded in a “100-year storm” is located in the “100-year flood zone.” The “100-year flood zone” has a 1% chance of being flooded in any given year. As noted, however, with climate change and rising sea levels, the historical averages start to become less predictive, making it likely that “100-year storms” and “100-year floods” will occur more often than the historical average would suggest.
It’s more like “George Orwell was right.” We’re kept in a constant state of fear and anxiety. Every other TV news item seems to be preceded by “Breaking News!” even if its “Sun to rise in East.”
Being a blizzard, these are in dug years.
The solution is clear. Get your weather news from sensible, accurate NWS, not sensationalist CNN.
Once the smart people abandon cable news to the Jerry Springer crowd, it’ll get even crazier. But since we don’t interact with those folks, it won’t bother us.
That’s my plan and I’m sticking to it. Just say “No” to the 24 hour fake news coverage.
I agree with NWS being better than CNN, but to use the word accurate in the same sentence is very misleading. :rolleyes::rolleyes:
Ask any aerial mapping pilot. :p:p 
Well you can hound them all you want but the clever fox wins again in the ratings, much to a wider dismay.
The thing we seem to get a lot here is that this day/week/month/year was the somethingest something since records began. The driest July, the most variable 3rd week in August, or the least humid October 12th since records began. It started off with ‘the hottest summer’, but it’s a race to the bottom now.