Color-coded maps and closer-up views show potential storm surge from up to 3 feet to greater than 9 feet. (Source: www.nhc.noaa.gov)
Last Modified: Monday, July 07, 2014 11:36 AMThe 2014 Atlantic hurricane season is in full swing, with Hurricane Arthur being the first named storm. And for the first time, residents can see the possible strength and location of a storm’s surge before it makes landfall.
The Experimental Potential Storm Surge Flooding Map is issued by the National Hurricane Center and uses different colors to indicate the height of storm surge. An area shaded in blue means the surge could be up to 3 feet above ground; yellow indicates a surge of more than 3 feet above ground; orange is more than 6 feet; and red is more than 9 feet.
The map — available at www.nhc.noaa.gov — allows users to zoom in and get a closer view of the storm surge and flooding potential. The website also has separate maps for wind speed probability and rainfall potential.
Roger Erickson, a meteorologist with National Weather Service office in Lake Charles, said he has used the map in house for the last couple of years. Now that it’s ready for public use, he said residents can see how storm surge could affect their area.
“It’s pretty much a standardized product that’s being displayed on the Web page,” he said. “This graphic sort of takes that mystery out of the equation in that it’s subtracting out the ground elevation for residents.”
Erickson said a storm surge map would likely be issued “once a watch is issued,” or about two days in advance of landfall. The map would be updated every six hours.
“You’re not going to see this four days out,” he said.
The storm surge map came about through work by National Hurricane Center officials and weather officials along the Gulf and Atlantic coasts, who, Erickson said, wanted “a graphical representation of storm surge.”
“The problem that we had was saying a 10- to 15-foot storm surge wasn’t really giving a depiction to people in the community as to what that meant to them,” he said. “They weren’t aware of what the risk was.”
Dick Gremillion, director of the Calcasieu Parish Office of Emergency Preparedness, said the storm surge map is a good addition, especially during situations when a weaker storm is approaching and some residents think it won’t have any effect.
“With the low elevation we have, it’s a big deal for us,” he said. “From a warning standpoint, it’s telling people what to do over time.”
A recent report from the hurricane center said weaker storms can have just as much effect as strong hurricanes. It said six of the 10 deadliest storms in the Atlantic were “tropical storms or Category 1 hurricanes at landfall.”
Of the Atlantic tropical cyclones that formed from 1963 to 2012, “roughly 90 percent of the deaths occurred in water-related incidents, most by drowning.” The report also said that “storm surge was responsible for about half of the fatalities.”
Gremillion said Hurricane Sandy was a good example of a storm that was not extremely strong at landfall in 2012, but still had a strong storm surge. According to the hurricane center, Sandy caused more than 70 deaths and over $50 billion in damage in the U.S. alone.
Hurricane Isaac was barely a tropical storm when it reached New Orleans area in August 2012. But Gremillion said the storm surge in some areas was higher than when Hurricane Katrina, a Category 3 storm at landfall, came ashore in August 2005.
“All we could do before (the map) was say we think surge will be x feet, like a tropical storm surge would be 1 to 2 feet,” Gremillion said. “Now the map will give what the (hurricane center) predicts those numbers will be.”
With new programs like Google Earth and Web page improvements, Erickson said it has made it easier to display the effects of a hurricane or tropical storm.
Starting next year, Erickson said weather officials will issue storm surge warnings separately. Hurricane or tropical storm warnings will focus mainly on wind.
“Before we issue a storm surge warning, we need to be producing graphics that show storm surge,” he said.
Erickson said the local weather service office will display maps online — at www.srh.noaa.gov/lch — for any tropical storms or hurricanes that would affect the area.
Hurricane season lasts until Nov. 30.