June 22, 2009
Earlier severe storm warnings possible
U.S. scientists say satellite observations of cloud temperatures might allow severe thunderstorm warnings to be issued up to 45 minutes earlier than usual.
Researchers at the University of Wisconsin-Madison said such temperature measurements would be more accurate and quicker than relying on traditional radar alone.
Scientists from the university's Cooperative Institute for Meteorological Satellite Studies developed a way to measure temperature changes in the tops of clouds to improve forecast times for rapidly growing storms.
The value of detecting and analyzing these changes is that we can get up to a 45-minute jump on radar detection of the same storm system, said institute scientist Wayne Feltz.
He said clouds begin cooling long before radar can identify them as storms. As a warm cumulus cloud grows and expands upward into higher altitudes, it will rapidly cool. Rapid cloud-top cooling would indicate a cloud top is rising into the frigid upper reaches of the atmosphere and can reveal the formation of a severe storm.
Feltz, Kris Bedka and National Oceanic and Atmospheric Administration scientist Tim Schmit demonstrated the technique during the recent annual Hazardous Weather Testbed meeting at NOAA's Storm Prediction Center in Norman, Okla.