Consider the following: A robbery suspect says he was at a scene 6 hours before a robbery was determined to have occurred. He admits he left his drink behind at the scene but says he left the location hours before. If the suspect is telling the truth, should the ice in the drink have melted from the time the suspect left to the time law enforcement arrived? In another case, a husband accused of killing his wife says he was outside, lounging by the pool when she fell down the stairs. Were the weather conditions at the time of the murder conducive to sitting poolside?
In each of those examples a forensic meteorologist was called in to provide a key piece of evidence.
Yet, at least by name, forensic meteorology hasn’t been around for long. In the last decade, the American Meteorological Society (AMS) has included forensic meteorology among its areas of specialization. Out of more than 9,750 professional AMS members, 108 list forensic meteorology as their main expertise.
Elizabeth Austin, who holds a Ph.D. in physics from the University of Nevada-Reno, is one of them and serves on the AMS Board of Certified Consulting Meteorologists. When Austin was an undergraduate studying atmospheric science in the 1980s, she says forensic meteorology wasn’t talked about. She first heard of forensic meteorology when she was getting her master’s in atmospheric physics. Now, she says forensic meteorology is more of a hot topic. Austin helps teach a combined undergraduate- and graduate-level forensic meteorology course every other year at the University of Nevada-Reno. In addition to meteorology, the course includes case studies, case work, reports (including a federal Rule 26 report), depositions, and a mock trial held in the courtroom of the National Judicial College, located on campus. For the annual AMS meeting in January, Austin and others are putting together a day-long workshop on forensic meteorology.
Like law enforcement, forensic meteorologists find that cases vary greatly. Sometimes they are relatively basic. Austin, president of WeatherExtreme Ltd., an atmospheric research and consulting company since 1994, gives the example of a case she worked in Reno. A man accused of attempting to bomb an IRS building said it was raining when he bought fertilizer, which allegedly was used to make a bomb. Austin was asked to determine if it had been raining.
Cases can also be more complicated. Frequently, Austin is called to help at the scene of an airplane crash, which requires looking not only at weather conditions on the ground, but in the sky as well. In some of these cases, she has needed to collect data from foreign countries, which haven’t always been willing to share their data, or when they have, it’s been more costly than in the United States.
Weather can also play a part in environmental crimes. Stephen Harned, a certified consulting meteorologist and president of Atlantic States Weather Inc. in Cary, N.C., has been a meteorologist for 40 years and has had a consulting firm specializing in forensic meteorology for the past seven. Harned recently was asked to testify about how much rain fell in an area where illegal dumping of hog waste was thought to have occurred.
Often Harned is asked to determine wind speed and whether or not wind speeds were high enough to cause the damage being claimed by homeowners.
Harned says he has not come across a case in which there are no answers.
“There’s enough data and understanding among forensic meteorologists to be able to reconstruct what happened at a specific location and time,” he explains.
To do so, forensic meteorologists use radar, satellite, models and data from various reputable sources.
Obtaining weather data doesn’t always require a forensic meteorologist.
“Law enforcement can do quite a bit on their own,” Austin says, noting that if the case requires expert court testimony, they will want to hire a forensic meteorologist.
Knowing where to find the data isn’t always easy, but there are lots of data out there.