No matter how sophisticated the instrument or how advanced the computer-modeling technique, it’s nearly impossible to always be 100 percent accurate when making weather predictions.
“Like predicting the outcome of a sports game or the stock market, forecasting the weather is always a challenge,” says Douglas Hilderbrand, meteorologist at the National Oceanic and Atmospheric Administration (NOAA). “There are many factors that go into how a storm develops and how the atmosphere interacts with the earth. It’s a dynamic and very complex process.”
While the use of computers in weather forecasting has greatly increased accuracy, limitations in weather forecasting also arise because we cannot observe every single factor that contributes to weather conditions.
“We can’t be perfect in our predictions because the atmosphere is so vast—it’s impossible to observe and know everything about every bit of atmosphere and the planet,” says Hilderbrand. “If we could observe everything, then theoretically, we could predict with 100 percent accuracy.”
Unfortunately, the science of weather always butts up against these observational limits. The data we have on the weather is never complete. In practical terms, this means you sometimes end up not bringing an umbrella to work on days when it rains.
Because there will always be a degree of uncertainty in determining future weather, a meteorologist might rely on something that’s more of an art than a science when it comes to making weather predictions.
Predicting the weather is a skill gained through experience. Most often, it takes place on a local level where a meteorologist is able to recognize certain patterns based on what he or she has seen before. This allows the meteorologist to make a prediction that may be different from the computer models.
This process of gathering all the evidence and weighing it against past events to make a prediction is at the core of weather forecasting. In some ways, you could say it’s a more sophisticated version of how the first caveman started predicting the weather by watching clouds. The human mind is still needed to fill out the facts and complete the picture.
“Thinking of a detective is a good analogy here,” Hilderbrand says. “You take what you’ve seen, what you know, put it together and try to make an accurate picture of what will happen.”
Hilderbrand goes on to say that perhaps the most important part of forecasting is the ability to communicate complex data to the public. He reminds us that a good forecast doesn’t guarantee anything. Rather, “a valuable forecast will always acknowledge its uncertainty.”
Perhaps the most popular nonscientific resource for predicting the weather is The Old Farmer’s Almanac. Learn more about this annual publication and why so many people continue to swear by it in the next post.