How do search and rescue teams track weather in the field?

The good news for search and rescue workers (and anyone who may find themselves needing to be searched for and rescued) is that they don't have to simply toss some grass in the air to see which way the wind's blowing or wait for Aunt Bessie's arthritis to flare up to know that a storm's a-brewing. There is plenty of weather tracking technology available to both prepare for and monitor conditions in the field.

Boats and helicopters often come equipped with radars that track storms in the surrounding area and measure their intensity, allowing operators to navigate around them. Weather radar has existed since the 1940s and now comes in digital and color formats that alert users to oncoming storms and related turbulence by looking for heavy rain clouds.

Radar sends beam pulses (short radio waves) into the surrounding area which are reflected back by objects like raindrops and hail. By calculating the length of time a pulse takes to hit its target and return, the radar can determine how far away the target (like the rain cloud) is. Weather radars have their limits, however. They track moisture, like rain, hail and wet snow, but not clouds. They also have a harder time measuring "dry" precipitation like harder snow and ice crystals [sources: Baur, National Weather Service].

Search and rescue workers traveling by foot can use commercially available mobile and hand-held weather reading equipment designed to provide site-specific information on the ground. Mobile weather stations may look like they were designed in a junkyard or basement, what with their resemblance to souped-up clothes irons, but these lightweight machines are capable of providing lots of vital information. Modern versions are equipped with an LCD screen that tracks everything from temperatures and wind speed and direction to rainfall levels and air pressure. They can also provide forecasts and usually some historical weather data [source: Ambient Weather].

Even more compact are hand-held weather monitors, nifty little tools that for a couple hundred bucks let users track wind speeds and gusts, air, water and snow temperature, barometric pressure levels (falling barometric pressure often indicates bad weather ahead), humidity and dew point. That's a lot of information for a device that weighs all of 2 ounces (57 grams) [source: Ambient Weather].

Other technologies have been developed to help rescuers predict the effects of weather specific to certain types of search and rescue operations. U.S. Coast Guard workers in Long Island Sound, for example, use a computer program to create "drift models" that predict how wind and currents might move a person lost at sea. Similar software has also been used to find Air France Flight 447 crash wreckage in waters off Brazil and monitor Japanese tsunami debris in the Pacific Ocean [sources: Kramer, U.S. Coast Guard, NOAA].

Firefighters and rescue workers, meanwhile, often rely on information from Remote Automated Weather Stations (RAWS) to monitor weather during forest fires. A network of roughly 2,200 RAWS are scattered across the United States, operated by the National Interagency Fire Center and used to predict fire patterns, based on wind and air conditions [sources: Forest Technology Services, U.S. Department of Commerce].

Much of the RAWS data is also available to anyone with access to the web. ROMAN is a Web site operated by the National Oceanic and Atmospheric Administration that provides detailed weather information gleaned directly from the National Weather Service and the RAWS network. Short for Real-time Observation Monitor and Analysis Network, the site allows users to search with geographic coordinates and obtain information about current weather conditions as well as detailed 24-hour forecasts[source: Careless].

There is one more noteworthy piece of technology that will help reduce the danger of search and rescue operations in severe weather situations. Unmanned drones, best-known for military and surveillance operations, can also be used to locate missing or stranded persons. Drones are equipped with cameras, infrared and other technologies that allow them to pinpoint a person's location or determine conditions inside a burning building or analyze weather data. This can save rescue workers precious time and resources. Currently drones are not used in search and rescue operations but the U.S. Coast Guard is considering purchasing some for extreme weather conditions [source: Practical Sailor].