'Cone of Uncertainty' to Shrink in Hurricane Forecasts

The “cone of uncertainty” that has been the bane of hurricane forecasters and watchers will be shrinking in the upcoming storm season because records have been improved, partly by information gleaned from prior years’ devastation.

The forecast cone, which the National Hurricane Center uses to indicate information on a storm’s predicted track, has become a topic of debate over recent years because many people misinterpret the data, Forbes magazine reported.

On Monday, the National Hurricane Center announced it would be shrinking the cone and implementing several other changes to help streamline how hurricane warnings are issued.

In addition to a smaller forecast cone, the center in Miami will extend advisories to 72 hours prior to storms and introduce graphics estimating the time of arrival of tropical-storm-force winds.

“The changes are to improve information contained in the hurricane center products and to provide it in maybe easier to understand formats,” said Dan Brown, a senior hurricane specialist in charge of warning coordination, The Miami Herald reported.

Last year’s Atlantic hurricane season is regarded as the most expensive experienced by the U.S. and, according to early forecasts, 2018 is shaping up to be above average, Bloomberg reported.

In previous years, the hurricane center relied on the cone to establish a probable track of storms based on the previous five-year record of forecast errors, but this only provided a probable track about two-thirds of the time, the Herald said.

Brown said forecasters have been able to narrow the cone based on improved forecast tracks in recent years.

They have also been able to make improvements by including a five-day forecast and adding tropical storm force wind projections.

However, he cautioned that it is still just an estimate and that “a third of the time storms can still fall outside the cone,” per the Herald.

“It doesn't provide you with any indication of potential impacts. It's only showing you where the center is likely to track,” he said.

• What Is the Best Hurricane Model?
• Tropical Storms Jose, Katia Shadowing Hurricane Irma