The Forecast Calls for Shorts

December 4, 2020

in A World Without Statistics

When astronomer William Ernest Cooke was hired to run the new Perth Observatory at the end of the 19th century, he also was charged with providing weather forecasts for the surrounding areas in Western Australia. But Cooke was not satisfied with merely presenting his best forecast—he also wanted to provide the public with a measure of its uncertainty. So, in 1905, his team began attaching uncertainty values on a five-point scale to their twice-daily forecasts.

Indeed, the forecasts he gave the highest rating to turned out to be correct 98.5% of the time, while those given a rating in one of the two most uncertain categories were only correct for 56.5% of the forecasts.

The century following these pioneering probability-based weather forecasts brought vast improvements due to the same themes that improve the quality of any statistical enterprise:

  • Systematically Collected Data - remote sensing devices, including satellites, now automatically transfer data with nearly universal coverage of the planet
  • Sound Statistical Models - now informed by a scientific understanding of the relationships among dozens of measured variables
  • Computational Efficiency - weather forecasts and “cloud” computing make a perfect pair
  • Statistical Reporting - forecasts now routinely carry a prediction, and an assessment of the uncertainty over time and space, of multiple aspects of the weather

If it wasn’t for statistics, we wouldn’t know the probability of rain tomorrow, and we wouldn’t know how to dress for the weather today.