The 2005 hurricane season was astoundingly active, setting new records left and right. Then 2020 happened, rewriting the record books. A lot of things changed over the 15 years between those historic seasons. Understanding those differences can help put the 2020 season into perspective.
The National Hurricane Center’s average track error – the difference between where the center of a tropical system is forecast versus where it actually ends up – has steadily improved for years. 2020’s numbers won’t be official until next spring.
This means that the “forecast cone” – where the center of a storm should fall within two-thirds of the time – has gotten quite a bit smaller. More precise forecasts lead to fewer people evacuate when it’s not necessary.
Intensity forecasts have long plagued forecasters, but those have also improved despite the challenges.
Satellites are crucial for tracking tropical systems since they allow meteorologists to see what’s happening far from land or ships. Surveillance over the Atlantic got a big boost starting in 2017 after the launch of the GOES-16 satellite.
Compared to the previous generation of satellites, GOES-16 can “see” five times more kinds of data at quadruple the resolution, and it scans all of that five times faster.
Satellite image of Hurricane Iota on Nov. 16, 2020. (NOAA/CIRA)
Meteorologists now watch tropical systems in more detail than was possible in 2005. It’s not just human eyes analyzing the data, though. It also feeds into complex computer simulations of the atmosphere.
Just like satellites, computer models’ resolution has drastically improved in the past 15 years thanks to big leaps in computing ability. This means they make more detailed, localized predictions. The main American forecast model, for example, produced a forecast point every 22 miles in 2005, but is now every 8 miles.
“Ensemble” forecasts are more common now, too. The phrase “two heads are better than one” suggests that a couple of people thinking about a problem give a better answer. In this case, it’s more like a few dozen heads, and putting those different forecasts together makes a better one overall.
Spaghetti model from Tropical Storm Zeta during the 2020 hurricane season.
To make all this happen, the models need good information to start with. Scientists have worked to put in more data, and also have different pieces (such as water and land modeling) better integrate with each other.
A hurricane’s storm surge, the water it pushes ashore on top of normal tides, can cause devastation and death. Forecasts in 2005 mentioned storm surge flooding, but there wasn’t much detail.
2008’s Hurricane Ike, followed by Hurricane Sandy in 2012, showed that storm surge needed more attention.
In 2014, the National Hurricane Center began experimenting with new storm surge information. That led to maps showing the so-called “reasonable worst-case scenario” storm surge flooding for landfalling storms in 2016 and storm surge watches and warnings in 2017.
In 2005, Facebook was just one year old and limited almost exclusively to college and high school students. Twitter didn’t even exist, and neither did the iPhone.
Today, it’s hard to imagine not getting weather information from an app on our smartphone or by asking a meteorologist a question about the forecast on social media. Those stronger connections can be a double-edged sword.
“The biggest change has been social media for good and bad. We are able to communicate better with these devices in our hands. But I’ve also seen rumor and false information spread too,” says Mike Clay, chief meteorologist at Bay News 9 in Tampa, Fla. He adds that coastal residents are “a hurricane-savvy bunch” and many have learned who to trust.
The 2020 season had a couple more named systems than in 2005, but the 2005 season was deadlier and more destructive. The official death toll in 2005 was nearly 4,000, most of which came from Hurricane Katrina and Hurricane Stan.
Despite a record number of landfalls in the United States, the 2020 hurricane season was less costly than the 2005 season. Even so, it’ll take a long time for some areas to recover.