New model to forecast rapid hurricane strengthening
Jun 02, 2012 (Sun Sentinel - McClatchy-Tribune Information Services via COMTEX) --
Forecasters at the National Hurricane Center admit they struggle to anticipate when tropical systems might rapidly intensify. That could be troublesome if a storm spins up quickly just before landfall, and residents are caught by surprise.
That's what happened when Hurricane Charley rapidly strengthened from a Category 2 to a Category 4 system with sustained winds of 145 mph before slamming southwest Florida in August 2004.
This year, the hurricane center hopes to receive a boost from a new computer model, which will use satellite images to analyze a hurricane's structure and attempt to determine if an eyewall replacement cycle is starting.
If so, it would be a key indicator that a storm is on the verge of exploding in strength -- or weakening quickly, said Jim Kossin, a National Oceanic and Atmospheric Administration scientist.
"Hurricanes usually strengthen and grow gradually over time, but eyewall replacement cycles can cause very sudden changes in size and intensity," said Kossin, who led the effort to create the model.
A hurricane's eyewall is composed of a band of clouds around the center. It also is where the most intense winds and rain can be found. In an eyewall replacement, a second band forms around the original and overtakes it. The cycle is common in powerful, long-lived hurricanes.
"As it was approaching New Orleans, Hurricane Katrina weakened but grew in size because of an eyewall replacement cycle, and the huge wind field led to an enormous storm surge that devastated the Gulf Coast," Kossin said.
NOAA plans to put the new model through its paces when the first hurricane emerges in the Atlantic Ocean of the Gulf of Mexico this year.
James Franklin, top hurricane specialist at the hurricane center, said the model should help forecasters improve intensity predictions, an area where forecasters have made little progress over the past several decades.
"This is an important first step toward understanding how we can use the eyewall cycle to someday improve intensity forecasts," he said.
firstname.lastname@example.org or 954-572-2085. Blog: sunsentinel.com/kenkaye
___ (c)2012 the Sun Sentinel (Fort Lauderdale, Fla.) Visit the Sun Sentinel
(Fort Lauderdale, Fla.) at www.sun-sentinel.com Distributed by MCT Information
[ Back To SIP Trunking Home's Homepage ]