Forecaster Drawn to Weather by Its Uncertainty

The clouds hugged the Texas Hill Country on a gray day 27 years ago. Vice President Lyndon B. Johnson waited impatiently for word that he could fly out of his ranch on the Pedernales River.

The flight hinged on a National Weather Service forecast, left to a neophyte weatherman with more than a little awe of the vice president.

Ron McPherson said it was one of his toughest calls in three decades of forecasting: “I was a 22-year-old kid with a year’s service and here’s a vice president who wants to get out of his ranch. When he wanted to go somewhere, he wanted to go. He didn’t take too kindly to the clouds covering the hills.”

But for McPherson, there was no other way. Johnson had to make it to Austin by car. Johnson’s pilot let McPherson know that the vice president was not too happy with the arrogance of the weather.

The memory has stayed with McPherson through his career, which began as an undergraduate intern in 1959 while at the University of Texas in Austin, one that has now taken him to the agency’s second-highest post.

He was named deputy director of the weather service in September and started work in mid-October, in charge of day-to-day operations at an organization attempting to move into the 21st Century.

“But what better person is there than a guy who worked his way up in the system?” asked Don Witten, a spokesman for the National Oceanic and Atmospheric Administration, which operates the weather service.

The service has 299 offices nationwide responsible for watching and warning of storms, tornadoes, hurricanes and flash floods. It plays a key role in space and air travel and is at the edge of research into understanding such phenomena as drought, wind shear and turbulent storms that die almost as quickly as they erupt.

What attracts McPherson to weather, he said, is its uncertainty.

“It’s knowing that you’re dealing with something slippery. You’re trained to deal with uncertainty, fragments of evidence, more than any other profession than maybe law,” he said.

Those fragments come from scores of sources around the country and the world--from forecasters in the field and thousands of volunteer storm spotters, weather balloons and river forecasting centers at the headwaters of the nation’s major waterways, ships at sea and satellites hovering above the Equator and circling the poles.

The weather service, which traces its roots to the Army’s Signal Corps in the late 1800s, has sometimes been on the cutting edge of technology and other times lagged behind, McPherson said.

Now the weather service is trying to buy its way into the future, ordering up some sophisticated new electronic equipment to replace some of its antiquated methods and gear. The new probes will allow forecasters to look inside a major storm system and maybe even predict a tornado in the embryonic stage, or the kinds of storms and squalls that spark killer flash floods.

It is part of the NEXRAD project of the service, the Air Force and the Federal Aviation Administration.

The basic unit is automated Doppler radar, which will allow meteorologists to look inside weather systems to see the movement of water droplets, vapor and dust particles that will betray otherwise invisible winds and air turbulence, which will in turn betray the formation of severe storms and tornadoes.

Doppler radar is more refined than current radar, which can only detect water in weather systems, but not its movement. A Doppler system reads the returning radar echo and determines whether it is shortening or lengthening, much the way the ear can determine that an approaching ambulance siren has a higher pitch than one going away. Computers can then give operators a more instant and fluid reading on what is going on inside clouds.

The first of the 170 to 190 units will be installed in the early 1990s at a cost of $2.5 million each.

McPherson hopes, too, that they will help explain how the weather systems work.

“You can’t forecast what you don’t understand, and you have to be able to observe what you’re going to forecast.”