National weather data
The National Oceanic and Atmospheric Administration’s (NOAA’s) National Weather Service issues weather warnings and forecasts, but doesn’t archive data.
NOAA’s National Climatic Data Center has the world’s largest active archive of weather data. NCDC produces numerous climate publications and responds to data requests from all over the world. If law enforcement needs to know what the weather was like on a specific day and time, NCDC has the answer.
NOAA Meteorologist Scott Stephens often receives calls from law enforcement trying to determine if there was snow on the ground, if there was a thunderstorm, or what the temperatures were. In June, for example, he received a call from an officer looking to confirm that temperatures were above a certain threshold because a child had been left in a vehicle.
To obtain answers to these questions, NOAA looks at surface data from airport weather stations that deliver hour-by-hour observations, and from its larger network of weather stations staffed by volunteers, or cooperative observers who measure basic parameters.
NCDC is the official U.S. archive for climatic records. As such, NCDC can certify copies of all records available from NCDC archives. As an archive facility, the only fact that NCDC can attest to is that exact duplicates of climatic records on file at this center have been provided to those that request such data. The standard Department of Commerce or general certification of authenticity accomplishes this. That’s important because records that are to be submitted as evidence in court in most states require authentication.
There is a charge for certified reports. Via the Web site, the base price is $69 while the cost for a paper copy is $109, says Stephens. If more data is needed, the cost is higher.
Regional weather data
NCDC is part of a three-tier national climate services program, which includes six regional climate centers and state climatologists.
At the Western Regional Climate Center at the Desert Research Institute in Reno, Nev., Jim Ashby often received calls from law enforcement working on crash reports. Ashby was a climatologist for 30 years and retired in June. To answer law enforcement inquiries, he would tap into the regional center’s many data sources. They include daily climate observations from more than 2,600 active stations, summarized monthly climate data from 5,240 stations, hourly precipitation data from more than 1,930 stations, twice-daily upper air soundings from about 50 stations, surface airways hourly observations from more than 1,800 stations nationwide, the Remote Automatic Weather Stations system, historic lightning data through 1996, access to Natural Resources Conservation Service SNOTEL (a network of snowpack data collection sites), 3,000 climate stations on the Web for the Western states, and more than 200,000 Web pages.
Regional centers know where the closest weather observation stations are relative to a crime scene. Austin notes personal weather stations, which are not official, can have reliable data, but not always. For example, they might be set up in a location where the wind is blocked part of the time.
Because crimes or traffic crashes don’t always occur near an official weather station, or there may not be a weather station of any kind around for miles, Ashby advises law enforcement officers note the weather at the time of an incident — especially if it’s windy or there’s a thunderstorm in the area.
“These events can be very local in nature and the nearest station may fail to mention wind or thunder,” he says.