New storm gets new cone: National Hurricane Center has experimental cone up and running

Tropical Storm Francine formed in the Gulf of Mexico Monday to become the sixth named storm of the 2024 Atlantic hurricane season. Forecasters expect it to strengthen into Hurricane Francine before it makes landfall late Wednesday night, likely in Louisiana.

The National Hurricane Center's new experimental cone of concern graphic is up and running, but so far it's very similar to the regular cone. The new cone will include inland watches and warnings.

The experimental tropical cyclone forecast cone graphic launched in mid-August for Hurricane Ernesto.

Compare NHC new cone with original cone for Tropical Storm Francine

Use the slider on the right to compare the original cone to the new cone. The experimental one is on the left.

Since there are no watches or warnings yet for inland areas, there aren't many differences between the two as of Monday morning.

Find the new cone at the National Hurricane Center by going to the graphics page for Potential Tropical Cyclone 6, then clicking on the New Experimental Cone link highlighted in red.

What's different with the National Hurricane Center's 'cone of uncertainty?'

Use the slider on the right to compare the prior cone to what it looked like beginning in August 2024. Click here if you can't see the interactive map to compare the two.

The "cone of death" we've seen for years shows a projected path of a tropical storm or hurricane, the likely timing of the storm, and wind watches and warnings for coastal areas. But since it's also important to show wind risks and potential impacts to areas away from the coast, the new experimental cone shows watches and warnings issued for interior counties.

The watches and warnings will take precedence over the cone in the new version, the National Hurricane Center said, to help residents understand the risks of strong winds.

"The biggest change to the cone is the addition of the inland wind warnings. The National Weather Service has issued those for years," said National Hurricane Center Deputy Director Jamie Rhome.

"We're placing that information on the (NHC) cone for a more comprehensive view of the threat so people don't have to go to two different websites. All the information is seamlessly merged together."

Differences you'll see:

• Watches and warnings for inland counties, not just coastal areas.

• White transparent shading for the entire five-day forecast, instead of white stippling (dots) for the four- and five-day forecast.

With the previous emphasis on watches and warnings issued along Florida's coasts, many inland residents and visitors were unaware of the wind dangers an approaching storm could have well away from the coast.

New Hurricane Center hopes new cone deemphasizes Saffir-Simpson Scale

"We're excited. It's a big step forward for us and the people we serve. It's a better way to convey information," Rhome said.

"We hope it gets people to stop fixating on less reliable tools like the Saffir-Simpson Scale. There are more accurate ways to convey actual wind impacts in your community and at your home.

"The Saffir-Simpson Scale doesn't allow you to understand what the actual impact may be where you live. The Saffir-Simpson scale tells you peak wind (associated with a tropical storm or hurricane) but it may not be that over your community.

"A Category 5 hurricane over Vero Beach doesn't mean Category 5 winds everywhere in Vero Beach. That doesn't allow you to deduce impact or threats" where you live. "People misinterpret local impacts, with some overestimating the threat and some underestimating the threat."

"Explicit watches and warnings for high winds (in your county) allow you to prepare for tropical storms or hurricanes based on where you are."

Old cone not going anywhere yet

"The existing cone will still be there. If you're not ready to pivot to the new cone, the old one will still be widely available," Rhome said.

"Any time you launch something new, initially there can be a spin-up education period. There's going to be a period for growth as people get used to new way of viewing their risk."

On the National Hurricane Center's website, you'll have to click on a link to see the new cone.

National Hurricane Center wants public feedback on new cone of concern

"The new one will replace the existing cone after one to two years of feedback.

"If there's clear feedback — the colors aren't right, something isn't clear, the legend is confusing — then we'll make more changes. We want feedback to verify the changes are accomplishing what was intended. My guess is that there will be opinions for more additions and refinements and then there will be another year of testing with more feedback" before the new cone replaces the current cone.

The public can offer comments on the new cone here.

When the new cone is pulled up on NHC's website, there will be a link to a short survey. Rhome said every bit of feedback received will be looked at to determine how to proceed.

This article originally appeared on The Daytona Beach News-Journal: Tropical Storm Francine: NHC's new cone of concern. What changed?