- October 19, 2022
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Bob Bunting, CEO and chair of the Climate Adaptation Center, thinks Floridians will see hurricane forecast graphics a lot this summer.
The CAC’s forecast for the 2024 hurricane season predicted 24 named storms, 12 hurricanes and six major hurricanes. That’s double the amount of predicted major hurricanes in 2023.
Not only is the number of hurricanes increasing over time, but so is the intensity, according to Bunting.
“In general, the number of storms has really been increasing,” Bunting said. “But more importantly, the number of major hurricanes is on a tear…and it’s directly related to the warming climate.”
Bunting claimed that nowadays people don’t take an in-depth look at the forecast graphics that are flashed on a screen for a couple minutes. He said most people just look to see if they’re in the cone of uncertainty.
But this year, the National Hurricane Center is experimenting with a new version of the cone of uncertainty and advertising that Hurricane Threat Impact graphics could also be helpful for people to prepare for hurricanes.
Bunting met with the Observer to talk about some reasons why hurricanes are increasing in severity, and how to understand some of the common forecast graphics.
Bunting identified a couple of factors behind the CAC’s hurricane forecast, one of the most important being water temperature.
When waters are warmer, it gives hurricanes more latent energy to grow in intensity. As the storm rolls over warm oceans, it gathers energy and grows stronger.
Bunting said years ago it used to take tropical storms a couple of days to intensify into major hurricanes.
“Now, with this super warm, deep warmth that we see…those storms go over that same area and they can really spin up in a hurry, which is the frightening part of it, this rapid intensification,” Bunting said.
Another factor that impacts the intensity of a hurricane is wind shear. Hurricanes like to stay straight up and down, according to Bunting. With stronger wind shear, the storms are tilted, which causes them to waste energy, Bunting said.
As hurricane season approaches this year, so will La Niña, a natural climate pattern that decreases wind shear, leading to larger, stronger storms.
With an active hurricane season approaching, Bunting said it’s important for the public to be informed about how to read forecast graphics, especially with the population living near the coast increasing.
“This is why communities have to switch from reacting to events to planning for them,” Bunting said.
One of the most common graphics associated with an approaching hurricane is the cone of uncertainty. It’s a simple graphic, but Bunting said people often get confused about one thing: what does it mean to be outside of the zone?
“The cone is not a wrapper around the hurricane impacts, it’s a wrapper around where the center of the hurricane could pass,” Bunting said. “And I think that’s one of the things that confuses people.”
On the graphic, the “X” marks where the storm currently is. The yellow circle around the “X” indicates how large the storm is.
The solid area on the old graphic shows the course over the next two days. The more solid color signifies a more reliable prediction.
“The reason why they have it that way is they know pretty much where this thing is going to go. The variance in the path is not that great,” Bunting said.
That means forecasters know with little uncertainty where the storm will go over the course of 1-2 days. When the prediction goes further out to 4-5 days, that’s where more uncertainty comes into play, hence the less-than-solid color.
If you live within the cone, Bunting said you should take notice. But even if you’re outside of the cone but nearby, he said you should take notice.
“It doesn’t mean you’re going to miss the impacts of that hurricane, it means the center of that hurricane could be anywhere within that cone,” Bunting said. “But what happens around that hurricane is going to affect way more geography.”
This year, the National Hurricane Center (NHC) is adding more data about the watches and warnings associated with the storm.
This new version of the cone of uncertainty will have more colors to indicate inland tropical storm and hurricane watches and warnings that are in effect.
“Recommendations from social science research suggest that the addition of inland watches and warnings to the cone graphic will help communicate inland wind risk during tropical cyclone events while not overcomplicating the current version of the graphic with too many data layers,” an announcement from the NHC said.
The new version of the cone of uncertainty will also use the solid white shading for the entire 5-day forecast, rather than the different shading for different time periods.
When dealing with rapidly developing hurricanes, Bunting said it’s important to take into consideration the full extent of a storm’s impact and a certain level of unpredictability.
“That’s why, in a rapidly developing hurricane, we have to be so cautious that in the age of climate warning, we might not get the usual warning of days,” Bunting said. “That’s the scenario we have to be ready for.”
The National Weather Service also issues Hurricane Threats and Impacts graphics, which break down impacts into four categories: tropical wind, storm surge, flooding rain and tornadoes.
These graphics show the range of a storm’s impact related to the different conditions. In some instances, it shows that although an area is out of a storm’s direct path, there can still be severe weather.
Bunting said that storm surge is one that can happen even if the storm isn’t traveling near the area.
“The water rises because there’s less pressure, so it doesn't take the storm actually going on in your neighborhood for the sea level to rise,” Bunting said. "My point is that we could have two or three feet of sea level rise while it's not raining, while the sun is out.”
All four of the graphics have a legend that uses purple, red, orange, yellow and gray to signify the severity of the impact. Purple is an area threatened by major hurricane impacts or the most severe.
Overall, these graphics show that it’s not only about what happens in the eye of the storm but the related impacts around the storm, according to Bunting.
