Meteorologists have never gotten a shiny magazine cover or a brooding Aaron Sorkin film, and the weather-research hub of Norman, Oklahoma, is rarely mentioned in the same breath as Palo Alto. But over the past few decades, scientists have gotten significantly—even staggeringly—better at predicting the weather.
How much better? “A modern five-day forecast is as accurate as a one-day forecast was in 1980,” says a new paper, published last week in the journal Science. “Useful forecasts now reach nine to 10 days into the future.”
The paper is a birthday present from meteorology to itself: The American Meteorological Society turns 100 this year. But it also acts as a good report card on how far weather prediction has come.
“Modern 72-hour predictions of hurricane tracks are more accurate than 24-hour forecasts were 40 years ago,” the authors write. The federal government now predicts storm surge, stream level, and the likelihood of drought. It has also gotten better at talking about its forecasts: As I wrote in 2017, the National Weather Service has dropped professional jargon in favor of clear, direct, and everyday language.
“Everybody’s improving, and they’re improving a lot,” says Richard Alley, an author of the paper and a geoscientist at Penn State.
With the current polar vortex, the first signs came almost a month in advance. On the final day of 2018, scientists detected what they call a “sudden stratospheric warming event,” high above the North Pole. The stratosphere, a layer of air about 20 miles above the surface, was being rocked by waves of warm air from below.
“What happens in the Arctic does not stay in the Arctic,” warned the meteorologist Andrew Freedman at the time. “Sudden stratospheric warming events are known to affect the weather in the U.S. and Europe on a time delay.” The next 60 days would probably be colder than average, he said.
By January 20, much of North America hit its first cold snap of the season. Then, a week ago, the European weather model began to project that a dangerous air mass would descend over the central United States. “It’s safe to say that the [European] weather model cannot get any colder for the Midwest,” said the meteorologist Ryan Maue on Twitter. “Wind chills would be in the -40 degree to -50 degree Fahrenheit range as well. This would be bad … but hopefully the model moderates.”
The model barely budged. On Wednesday morning, Minneapolis recorded a wind chill of 52 degrees below zero.
This kind of pattern—where a seasonal climatic projection (“It will be colder than average at the end of the month”) precedes a definite week-ahead forecast (“It will be 40 degrees below zero on Tuesday”)—will become more common in the years to come. Meteorologists are increasingly uniting weather models and climate models, allowing them to project the general contours of a season as it begins.