(TNS) - National Hurricane Center forecasts have evolved beyond the staid Saffir-Simpson wind scale that shoehorns tropical cyclones into tidy categories while ignoring flooding waters from sea and sky.
This hurricane season, an array of products will alert to killer storm surge, predict arrival time of damaging winds and show storm size.
One forecast map will warn of systems that have the potential for cyclonic wind-up, but have not yet developed into a storm.
It’s all in an effort to inform the public beyond Saffir-Simpson, but is the public ready to digest more than categories 1, 2, 3, 4 and 5?
That was a question raised Tuesday at the National Hurricane Conference in New Orleans, where some emergency managers and broadcast meteorologists worried that information overload could cause confusion.
“We have so many watches and warnings. The general public can’t take all that information and absorb it all,” said Bill Quinlan, a forecaster with ABC-affiliate WCJB in Gainesville. “They don’t always understand the difference between a watch and warning, and now you’re going to have a tropical storm watch and warning, a hurricane watch and warning, a storm surge watch and warning.”
Quinlan was commenting on a discussion about how to convey forecast uncertainty while at the same time raising public awareness on the threat of storms.
The new storm surge watches and warnings build on previous surge inundation maps that show the potential depth of flooding from water forced ashore by a storm. They were tested experimentally in 2016 during Hurricanes Hermine and Matthew, but become operational this year and will light up cell phone alert systems if triggered just like hurricane watches and warnings.
In some cases, a storm surge warning — indicating the danger of life-threatening rising water — could be issued for a storm that hasn’t reached hurricane strength. A weaker storm with a large wind field can still push dangerous amounts of water ashore.
That worried John Scrivani, an emergency management administrator with the Virginia Department of Transportation, who said it’s going to be difficult to tell a politician that evacuations may be needed for a storm that’s not a hurricane.
“We are trying to get the public away from focusing on the wind but we still throw out this historical piece of wind data and it’s not good for perception,” Scrivani said about using Saffir-Simpson wind scale categories. “There are too many things thrown at the public. There is so much noise.”
Between 1963 and 2012, 49 percent of tropical cyclone deaths were storm surge related. Another 27 percent were attributed to rain accumulation.
Just 8 percent of deaths were from wind.
“I know it’s exhausting when all these watches and warning are going out, but if we can’t warn this nation on the number one hazard that has the greatest potential to take the most lives in a single day, then we are missing something,” said Jamie Rhome, leader of the storm surge unit at the National Hurricane Center.
Rhome argues that emergency managers can use the storm surge watches and warnings to validate evacuations.
And Rick Knabb, who is director of the National Hurricane Center until next month, said the additional forecast products will help people focus on impacts over the popular, but often misunderstood, forecast cone.
“We have had to strike a balance between creating too many warnings, too many products. There is a point of information overload,” Knabb said. “But I would turn back the clock 10 to 15 years when there was a lot of confusion because there was a lack of information.”
Another new item being used experimentally this year is a colorful map that will show when tropical storm-force winds will hit a specific area. This was developed so people will know when they need to have their preparations finished and for emergency managers who are making evacuation decisions.
Also, the National Hurricane Center will start issuing forecasts this year for systems that have yet to gain tropical cyclone status. The forecasts will look the same as traditional storm forecasts, but allow the hurricane center to issue advisories when a low pressure system may be building up steam.
Previously, the hurricane center could not issue advisories until a storm met the meteorological definition of a tropical cyclone — a problem if the storm formed close to shore.
“All of the fuss about why isn’t the hurricane center calling something a storm yet won’t matter anymore,” said James Franklin, chief of the NHC’s hurricane specialist unit. “This addresses a gap in our forecasting ability.”
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