As Irene battered the East Coast two weeks ago, Frank Lombardo knew that only after the rain and wind stopped and the floods receded, would his work begin.
That's because as a forensic meteorologist, Lombardo is often called on to consult on legal and insurance cases resulting from violent storms. His job, and that of any forensic meteorologist, is to reconstruct the weather conditions that occurred at a specific time and location in question by retrieving and analyzing archived atmospheric data and re-creating a time line of meteorological events.
"As soon as something happens…whether there's a catastrophic event or a minor localized event, forensic meteorologists understand things will quiet down, but in a few years from now, it will get into the courts," says Lombardo, president of WeatherWorks, Inc. The Hackettstown, N.J.–based company provides meteorological expertise to public and private sector organizations, including the media.
Described as a combination of science, art and interpretation, forensic meteorology mirrors the work that detectives do to solve crimes. Cases may involve whether lightning sparked a fire or, if someone slips and falls, whether ice on a property was to blame. Data comes from various sources, including observations, weather stations at airports, Doppler radar and satellite imagery, National Weather Service bulletins, and even tidal gages. Forensic meteorologists may also take their own measurements, such as wind velocity. Cases are mainly site-specific, and much of the problem-solving involves knowing what synoptic, or generalized, data is needed to reconstruct the micrometeorology at a particular location.
"A lot of what we depend on is experience, but we need tools of the industry, such as Doppler radar and good observations" to solve mysteries related to weather, Lombardo says.
He recounts one of his cases in which a crane collapsed near a building, injuring the operator. It was a blustery day, and the wind threshold of the crane ranged from approximately 48 to 56 kilometers per hour, according to the manufacturer. Hired by the operator, his charge was to determine how the localized weather influenced the crane's fall. Lombardo visited the site on a day that had similar conditions as when the accident occurred, and on noticing that the crane was positioned near a nine-meter wall, wondered if that had influenced the site's wind velocity. He measured the wind speed using an anemometer, noting that the wind intersected the wall at a 70 to 80 degree angle. By calculating simple vectors, he discovered that the wind speed near the crane was around 29 to 48 kilometers per hour, right at the edge of what the crane could withstand. "I secured information that supported the case that the [worker] shouldn't have been operating the crane," Lombardo says. "It wasn't his fault. It was a function of the wind converging on the wall, which increased the wind pressure on the crane, causing it to collapse."
Sometimes, data that is needed to decipher how atmospheric conditions affected a particular location and case is not available. Stephen Wistar, a forensic meteorologist with AccuWeather, consulted on hundreds of cases relating to Hurricane Katrina. Most of his investigations centered on insurance claims about whether wind or storm surge caused property damage. He lacked access to much of the typical data he would have used in similar circumstances because many of the standard tools, such as weather stations and tidal gages, failed when the storm hit. Instead, he utilized a massive computer model called "ADvanced CIRCulation" (ADCIRC), which predicts tidal and storm surge elevations and velocities over large areas. Combined with information he retrieved from Doppler radar sites outside of New Orleans, and on-site investigations he conducted himself, he was able to reconstruct time lines of property damage and state which hit property first—the wind or the water.