Panel Blames Outdated Equipment for Delay in Flash-Flood Warnings

Outmoded radar and inadequate telephone lines were responsible for the failure of National Weather Service forecasters to deliver adequate flash-flood warnings to parts of Ventura County and the San Fernando Valley devastated by recent storms, a special review panel reported Friday.

“Overall, we did a pretty good job, but it could have been better,” Tom Potter, the weather service’s regional director, told reporters after an intensive, weeklong analysis of operations at the agency’s Los Angeles headquarters. “The only way we’re going to be able to improve . . . is to acquire new technology.”

Although meteorologists issued heavy storm warnings five days before the first major front hit the coast Feb. 10, the agency’s network of 20- and 30-year-old radar was unable to pick up the kind of intense, isolated cloudbursts that sent a torrent of water racing down the Ventura River and caused flooding near the Sepulveda Basin in the San Fernando Valley, the agency’s internal panel reported.

A mudslide triggered by a flash flood killed a pregnant woman and her fiance as they slept in their home just north of Ventura. The swollen Ventura River swept away a few mobile homes and recreational vehicles at an RV park at the river’s mouth. In the Sepulveda Basin, nearly 50 motorists had to be rescued from their cars.

The fury of the two storms--each brought more than four inches of rain in a few hours--resulted in widespread criticism of the weather service.

While defending much of the service’s forecasting work as “excellent,” the three-member panel noted that problems in the Valley were complicated by the agency’s inability to connect by phone with a computer run by the Army Corps of Engineers. The newly established computer link would have allowed forecasters to get the latest information on rainfall totals and reservoir water levels, but the phone line was tied up.

“There was a two- or three-hour gap during the middle of the Sepulveda flood where the lines were busy,” said panel member Lee P. Krogh, who called for better coordination between the weather service and other agencies. “Some of this coordination was not as good as it could have been. It was a little rusty.”

Todd Morris, deputy meteorologist in charge of the Los Angeles headquarters during the storms, said the phone problem occurred because the weather service is not the only agency to use the computer line. “It may have been a case,” he said, “where we happened to be the second caller as opposed to the first caller . . . and we weren’t able to get into their computer.”

The situation is being corrected with a new line exclusively for weather information, panel members said. Meanwhile, the weather service is studying whether to add similar lines to connect with other agencies, such as the Los Angeles County Flood Control District and the county’s Office of Emergency Services.

The problem of outmoded radar also will be solved once the weather service completes a new nationwide system of 155 “Doppler radar” stations, giving forecasters an unprecedented look inside storms, panelists said.

Unlike today’s radar, which displays a storm as a one-dimensional “blob,” the new system will show exactly where rain is coming down and where winds are blowing. The information will be vital to keeping track of rainfall totals and predicting what a storm will do, agency officials said.

If the new radar had been installed, it would have given forecasters a far more accurate view of the intensive rain that descended into the Ventura River watershed and would have enabled them to order early evacuations.

The new technology has been in use for about two years in Oklahoma and is so effective that meteorologists can see the swirling of winds that portend a tornado, said Ron Alberty, director of radar operations there.

“That’s the kind of resolution we’re going to have to get” to anticipate possible flash-flood problems in small areas, Alberty said. “My belief is, within four or five years you’ll hear forecasts like: ‘The National Weather Service is forecasting this storm to intensify, and within an hour it will be producing two inches of rain per hour.’ And it will tell you where--which drainage station, which reservoir.”

The system, expected to cost $2 billion or $3 billion, represents the first attempt in decades to modernize technology within the weather service, possibly the only government agency that still trains some of its technicians in the use of vacuum tubes, officials said. The agency will place 10 Doppler radar stations in California.

Had such a radar been in place during the Sepulveda Basin flooding, Alberty said, “the National Weather Service would have been able to tell precisely how much rain was falling in that reservoir--in the reservoir, not just in the county.”