|Date:||January 28, 2017|
|Source:||Palm Beach Post|
The National Hurricane Center will unveil groundbreaking wind maps this storm season in an ongoing effort to steer attention to more tailored forecasts and away from the captivating, but clumsy, cone of uncertainty.
Forecasters hope the colorful graphics, which give an estimated time of arrival for tropical storm-force winds, will help make potentially life-saving decisions, such as when to evacuate or finish boarding up.
The maps answer one of the most-asked questions during the scramble before a storm; when will the winds reach me?
“The point of this new graphic is to tell people how long they have to get ready,” said James Franklin, chief of the National Hurricane Center’s hurricane specialist unit. “This identifies a period of time during which preparations should be completed before tropical storm-force winds arrive and make it too dangerous.”
The maps will be used experimentally for the 2017 hurricane season, which begins June 1, and rolled out as a permanent new product the following year if they work well.
Plans for this year include introducing two maps, one of which will tell the “earliest reasonable arrival time” for tropical storm-force winds of 39 mph or higher, and a second that will show the “most likely arrival time.”
Franklin said people will use the maps differently depending on the amount of risk they are willing to take as a storm approaches. While homeowners may want to know when they can expect the earliest winds to arrive so they can finish putting up storm shutters, emergency managers may use the most likely arrival time to determine evacuation orders.
“Both pieces are important,” Franklin said. “The earliest onset graphic is the one we really want people to be basing their preparations on.”
The new maps have been in the works for years and are still being reviewed by social scientists who may suggest changes in colors or wording. They build on maps and information already available at the hurricane center website, but that can be cumbersome to use, such as wind speed probability charts which show the chances of winds of a certain strength reaching specific cities.
Even some emergency managers struggle with the charts, Franklin said, relying instead on a single forecast that doesn’t recognize uncertainty, such as possible changes in the size or speed of a storm.
Hugh Willoughby, a retired 27-year veteran of the National Oceanic and Atmospheric Administration’s hurricane division and a professor at Florida International University, said knowing wind arrival times makes the new graphics “immensely more valuable.”
“Hurricanes are not something most people think about on a regular basis and suddenly they are thrust into making these very consequential decisions,” Willoughby said. “You want to give them all the help you can and we do OK with that, but OK isn’t always good enough.”
The NHC has introduced a handful of new forecast products in recent years, including storm surge inundation maps that were put in play for the first time during 2016’s Hurricane Hermine. Hermine broke Florida’s more than decade-long hurricane drought when it hit in the Big Bend region as a Category 1 storm in early September.
The center is also working on five-day track forecasts for systems that have yet to develop into official tropical cyclones so meteorologists won’t have to wait until the system organizes to issue advisories. The impetus for that change were storms such as 2015’s Tropical Storm Bill. The hurricane center was relatively confident Bill would become an organized storm, but it by the time it gained the technical characteristics of a tropical cyclone, it was nearly on top of the Texas coast.
Franklin said the new tools are aimed at giving people as much information as possible and get people away from relying only on the most well-known product — the cone of uncertainty.
“We don’t want people looking only at the skinny black line and assuming the forecast is going to be perfect and then being surprised when it’s not,” Franklin said. “With this, people don’t have to guess.”