October 7, 2005

Weather Officials Probe Katrina’s Strength

MIAMI -- Government hurricane specialists said Friday they are investigating whether Hurricane Katrina was actually a Category 3 storm, not a 4, when it struck the Gulf Coast.

Analyzing the hurricane's strength has been made more difficult because instruments used to measure the wind failed or were swept away when the storm hit Aug. 29, and communications was lost with a National Weather Service radar station in Slidell, La.

Hurricane specialists are examining data from planes that flew through the storm on the day it struck New Orleans, trying to gauge whether wind speed measurements accurately reflected conditions on the ground, said Jack Beven, hurricane specialist with the National Hurricane Center in Miami.

Any downgrade in strength could be a dark sign for New Orleans, where the storm levees are generally believed to be able to protect the city from the rains and surge of a Category 3. Portions of the levee system were either topped or failed in the storm, sending devastating floodwater into the heart of the city.

"It should be pointed out that New Orleans was on the western side of the hurricane, and regardless of how strong it was, New Orleans did not get the worst that the storm had to offer," Beven said.

Katrina struck at the mouth of the Mississippi River south of New Orleans at daybreak on Aug. 29. At the time, it was a Category 4, with wind speed of 135 mph, Beven said. The strongest part of the storm missed New Orleans and instead passed over the river's mouth and into the Mississippi Gulf Coast.

Scientists are also investigating why a 20-to-30-foot storm surge along the Mississippi coast seemed more consistent with a Category 5 hurricane than the designated Category 4, according to specialists at the hurricane center.

"At one point Katrina was a Category 5. It may have been that the winds died down to a Category 4 or 3, but the ocean was so stirred up by the hurricane that the surge was more equivalent to a 5," Beven said.