Posted: 11:27 am Thursday, April 17th, 2014
By Eliot Kleinberg
Starting this season, the National Hurricane Center is gearing up to display experimental graphics showing potential storm surge, on its web page, storm surge specialist Jamie Rhome said at a Thursday session at this week’s National Hurricane Conference in Orlando.
The graphic will be updated every six hours, and will reflect changes in a storm’s track or strength.
The goal, hurricane center director Rick Knabb told Thursday’s session, “is to enhance the real-time communication of the hazard. To give it more visibility and able communicators and emergency managers to have more tools in the box.”
And as early as 2015, the hurricane center will start issuing a new breed of watches and warnings, for storm surge.
Maps will show where surge could occur and how high above ground the water could reach in those areas. Watches would have their own point A and point B, independent of whatever evacuation borders counties have set.
“I think they’ll (storm surge graphics) work well in tandem,” Palm Beach County Emergency Manager Bill Johnson said Thursday. But, he said, “I have to make sure the public doesn’t second guess.”
Johnson said Palm Beach County’s unique complications — it’s huge and geographically diverse, its low areas are prone to profound rainfall flooding, and it’s next to a big lake ringed by a dike — mean he might make decisions that are only partially based on the storm surge graphic.
For example, he said, always keeping in mind the costs of mandatory evacuations, he might order one for only part of a zone.
“Evacuation is not an innocuous thing,” he said.
Storm surge isn’t as dramatic a factor in Palm Beach County and the Treasure Coast, because the ocean floor drops off precipitously just off the coast and the deep water absorbs much of the energy of a storm surge. The region also benefits from several ridges.
But that same deep water does aggravate waves, which can cause plenty of havoc right at the coast, where Palm Beach County has some homes worth more than a few dollars.
Storm surge, a June 2013 study said, does place three Palm Beach County zip codes — 33480 (Palm Beach), 33410 (Palm Beach Gardens) and 33458 (Jupiter) — in the top 10 in South Florida in terms of loss, because of the combination of surge and high property values.
Scientists have said even in a minimal storm, water would cover most or all of barrier islands and the mainland right along the Intracoastal Waterway, and in a Category 5 storm, the ocean could rise up to 10 feet above normal in coastal Palm Beach County and up to 15 feet on the Treasure Coast.
Parts of Jupiter, because of the Loxahatchee river, and coastal southern Boca Raton, crisscrossed with finger canals that open to the ocean, are especially vulnerable to surge.
A report issued this week at the hurricane conference showed 84 percent of those surveyed still believe, wrongly, that emergency managers order evacuations for wind. Instead, it’s water, by far the biggest killer, historically, in a hurricane.
At the session on Thursday, Rhome showed the highly vulnerable areas of southwest Florida; Charleston, S.C.; and Houston. Model maps showed surge water racing up inlets and bays as much as 60 miles inland, with calamitous results.
“Poll after poll after poll show that, with the exception of people along the beach, there is no awareness of how far the water can go,” Rhome said.
That southwest Florida graphic includes Fort Myers and Lee County. For John Wilson,who recently retired as Lee’s emergency manager, “it would have given a much clearer understanding of areas that might flood.”
Staff writer Eliot Kleinberg, who’s covered hurricanes for the Post for more than a quarter century, reports this week from the National Hurricane Conference in Orlando. Watch for tweets, blog postings, and web and print stories.