Study says 'specific' weather forecasts can't be made more than 10 days in advance

[mahatmakanejeeves]

Last edited Thu Nov 7, 2019, 05:39 PM - Edit history (1)

On the Washington Post website, the title is "Meteorologists say AccuWeather's unscientific forecasts are hurting their credibility." Surely you recall that Trump wanted to make the head of AccuWeather the new head of the National Weather Service. Something like that. I'll have to look it up.

{edited -- here it is:}

Trump taps AccuWeather CEO to head NOAA, breaking with precedent of nominating scientists

Capital Weather Gang • Analysis
Study says ‘specific’ weather forecasts can’t be made more than 10 days in advance

By Matthew Cappucci, Meteorologist, Capital Weather Gang
November 7 at 10:54 AM

Imagine someone telling you the weather forecast for New Year’s Day today, two months in advance, with exact temperature bounds and rainfall to a hundredth of an inch. Sounds too good to be true, yes?

A new study in Science says it’s simply not possible. But just how far can we take a day-by-day forecast?

The practical limit to daily forecasting

“A skillful forecast lead time of midlatitude instantaneous weather is around 10 days, which serves as the practical predictability limit,” according to a study published in April in the Journal of the Atmospheric Sciences.

Those limits aren’t likely to change much anytime soon. Even if scientists had the data they needed and a more perfect understanding of all forecasting’s complexities, skillful forecasts could extend out to about 14 or 15 days only, the 2019 study found, because of the chaotic nature of the atmosphere.

“Two weeks is about right. It’s as close to be the ultimate limit as we can demonstrate,” the study’s lead author told Science Magazine.

The American Meteorological Society agrees. Their statement on the limits of prediction, in place since 2015, states that “presently, forecasts of daily or specific weather conditions do not exhibit useful skill beyond eight days, meaning that their accuracy is low.”
....

AccuWeather’s long-range forecasting approach has elicited criticism across the meteorological enterprise for being overly specific and not communicating uncertainty. .... Why does AccuWeather issue such forecasts if they are beyond the bounds of modern-day science? ... “Personally, I think it’s marketing,” said Victor Gensini, an assistant professor of atmospheric sciences at Northern Illinois University, who specializes in long-range predictions of severe weather.
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The Washington Post is a customer of AccuWeather for weather services and forecasts in its print edition, for predictions no more than 10 days into the future.

Jason Samenow contributed to this report.

Matthew Cappucci is a meteorologist for Capital Weather Gang. He earned a B.A. in atmospheric sciences from Harvard University in 2019, and has contributed to The Washington Post since he was 18. He is an avid storm chaser and adventurer, and covers all types of weather, climate science, and astronomy. Follow https://twitter.com/MatthewCappucci

[Wellstone ruled]

1. One of the major

issues of Climate Change is the new unpredictable nature of the Global Atmosphere.