Newswise — A mobile Doppler radar tracking the twists and turns of air billowing around a wildland fire in Montana has gathered data that will shed light on fire dynamics and could help improve forecasting of these intense blazes and their weather impacts. Doppler on Wheels, a truck-mounted radar best known for its pioneering studies of tornadoes and hurricanes, probed the Robert Fire near Glacier National Park from July 30 through August 1. The fire began on July 23 and has burned more than 24,000 acres.
"With radar, you can penetrate through the plume and see how vigorously the air is moving up and down, and you can characterize the wind flows around the fire," explains Josh Wurman, an affiliate scientist at the National Center for Atmospheric Research (NCAR) and chief scientist for Doppler on Wheels (DOW).
The radar deployment in Montana was sponsored by the Wildland Fire Research and Development Collaboratory, an NCAR-based consortium of U.S. national laboratories, universities, and federal and state agencies dedicated to learning more about wildfires. The National Science Foundation, NCAR's principal sponsor, provides funding for the collaboratory and radars. DOW is based at the Center for Severe Weather Research, a nonprofit research organization located in Boulder.
At present, U.S. firefighters are usually guided by National Weather Service spot forecasts, which provide generalized area conditions and current wind speed and direction. But such tools cannot predict sudden shifts in wind, sometimes caused by the fire itself, which can unexpectedly drive flames in new directions. Even when larger-scale winds are light, the intense heat generated by a fire can produce tornado-like fire whirls and other phenomena that can play havoc with firefighting plans and fire warnings. In 1994, 14 firefighters died in a wildfire on Storm King Mountain in western Colorado when strong west winds triggered fire runs that spread as quickly as six to nine feet per second.
If the Montana sampling proves successful, mobile radar deployments could become a routine part of wildland fire monitoring. Eventually, radar data on erratic, dangerous winds might be transmitted to laboratories in real time and integrated into numerical models and decision support systems.
"Radar data could help us make short-term forecasts of where a fire is going to be hottest, what it's going to be like in two or three hours, and whether the wind is likely to shift," says Wurman. "If you know that type of information, you can fight a fire more efficiently and safely."
The fire/weather interaction can extend beyond the fire area itself. The largest wildland blazes may influence weather for many miles downstream as they shape larger-scale air flow and emit smoke and airborne particles. Researchers at NOAA's Forecast Systems Laboratory are exploring techniques to bring radar data into high-resolution weather forecast models so that the downstream weather effects might be captured more accurately.
On the Web
Wildland Fire R&D Collaboratoryhttp://www.rap.ucar.edu/projects/wfc
Robert Fire (interagency Web site): http://akteam.ak.blm.gov
RSS