Why Weather Forecasts Fail Big and Fail Often

Researchers at Tel Aviv University have quantified for the first time why weather forecasting is so fraught with error in all parts of the globe. Different regions have different challenges, according to Prof. Alpert of the Department of Geosciences, but predicting what will happen in the atmosphere remains a difficult undertaking despite advances in meteorological modeling technology.

A day after forecasters unanimously predicted a snowstorm of epic proportions for New York City, and the mayor ordered eight million people to stay off the roads, including takeout delivery providers, the predictions failed to materialize. The city received inches of snow rather than the feet predicted. A good thing, to be sure, but how did such dire predictions miss the mark?

“The researchers found the dominant factors clouding the accuracy of predictions comprised land-use changes (i.e. an area that had been covered in forest is suddenly bare), topography, particles in the atmosphere and population density.”

The most common challenge facing meteorologists—and the most difficult to incorporate into their modeling technology—are new land cover changes which affect how water collects or runs off, in turn affecting cloud formation and precipitation patterns.

On the Atlantic coast, a great number of factors complicate weather predictions, including fluctuating ocean temperatures, winds that change as they reach the coastline, and storms which either gain or lose energy depending on their trajectory.

During his Big Think interview, German psychologist Gerd Gigerenzer helped explain how statistical risk, most often expressed as an x-percent change of inclement weather, is rarely communicated effectively even by meteorologists:

Read more at Science Daily

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