Everyone Else is Doing It

April 29th, 2009

Posted by: Roger Pielke, Jr.

The WSJ today has an interesting article on seasonal forecasting of hurricanes (i.e., timescales under a year, unlike the 1-5 year predictions discussed here over the past week). The track record is not great:

Yet even as academics, government agencies and private industry crowd into the forecasting arena, they’re bumping up against obstacles that may render accurate forecasting so far ahead of time impossible. Some forecasts are based on past years with similar patterns, but the climatology record doesn’t go back far enough to lend much confidence. And it’s hard to even detect these weather patterns far in advance — even giant patterns that determine the intensity of a season. El Niño, or warming of Pacific Ocean waters, tends to suppress hurricanes; La Niña, unusually cold Pacific waters, tends to increase storm activity. Yet neither of these seasonal effects can be predicted with much reliability before the late spring.

“Until you really get into the spring and the weather patterns start to set up, it’s really hard to get any kind of decent forecast as to what’s going to go on in the summer and fall,” says Chuck Watson, who works on forecasts of damage from hurricanes. Anytime before spring, “You might as well throw a dart.”

Or hire a gibbon and a trance medium to compete with the dart thrower. That was the stunt dreamed up by reporter Bo Petersen of the Post & Courier of Charleston, S.C., in 2007, after several years of more straightforward reporting of professionals’ ultimately errant forecasts. The trance medium beat out Mr. Petersen, the gibbon, the dart thrower — and the pros. This comedic contest was borne out of a serious problem, according to Mr. Petersen: “The sense we got from emergency-management people here is that the forecasts had been so wrong that they were hearing from the public, ‘Why should we pay any attention to this stuff?’ “

Are gibbons monkeys? I digress. If seasonal forecasts have such little skill, which is acknowledged by some who issue them, then why do forecasters hold press conferences announcing them? Mr. Watson explains:

But why publish press releases and even, in some cases, hold press conferences? “Part of the reason we even do our press conference and release our data is, well, everyone else is,” Mr. Watson says. He adds that research funders generally encourage the publicizing of the fruits of their grant money: “From a funding and research standpoint, you’ve almost got to release it,” Mr. Watson says. “It’s part of that game.”

This reminds me of a cute, perhaps apocryphal story about Nobel Prize winning economist Kenneth Arrow:

As a weather forecaster in the Second World War, Arrow and his colleagues were told that their commanding officer needed a long-term forecast. The forecasters knew from experience that such forecasts had little scientific basis, and related this up the chain of command. The reply that came back was this: no matter, the general needs the forecast for planning purposes.

3 Responses to “Everyone Else is Doing It”

  1. Jon Frum Says:

    Gibbons are apes – more closely related to us than to monkeys.

    Regarding forcasts: Here in Boston, a long-time television metereologist retired years ago. Some time later, in a radio interview, he told why he left television. A twenty-something “consultant told him to do five-day forecasts. When he told the kid that no meterologist in the world could do five day forecasts in Boston, he was told that if he wouldn’t do it, they’d find someone who would. That’s when he quit. Now, they do seven-day forecasts.

    Isn’t it remarkable that they keep doing the seven-day forecasts, but they never review their past predictions? Each day, at each television station, the previous day’s forecast goes into the memory hole.

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  3. dean Says:

    I actually have seen TV weather that compares what happened to their prediction – but the comparison is always for the prediction only the day before.

    I have also heard what Jon Frum refers to. Weather is one of the most popular segments on local news, and no station can afford, ratings-wise, to have a shorter prediction as they will lose viewers.

    The irony is that while having a weather prediction for only a few days hurts ratings, most people know that 7-day forecasts are highly unreliable.

    Maybe the news should switch to climate forecasts instead of weather, since climate is easier to predict . . . ;)

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  5. Ryan Meyer Says:

    Here’s a post from Science Insider on the swine flu epidemic with a remarkably similar quotation:

    Another source of confusion is the value of computer models in anticipating the virus’s path. Besser said CDC has used models to look at questions such as the value of closing borders but stressed that they had their limits. “As many modelers as you have, you’ll have that number of estimates,” he said. Nicoll said that at this stage, we don’t know enough about this virus to reliably model it. Even so, that hasn’t stopped “everybody, at this point” from seeking modeling data, he noted.