NOAA'S NATIONAL WEATHER SERVICE ROLLS OUT
NEW WIND CHILL TEMPERATURE INDEX
New Formula Will Provide More Accurate Warnings for North America
November 1, 2001 NOAA's National Weather Service today implemented a new method to compute wind chill temperature to provide better winter weather warnings throughout the nation. For the first time, the index will include specific wind chill threshold values showing frostbite danger at given periods of time.
"We're proud that the new index reflects the best science, technology and computer modeling technology," said retired General Jack Kelly, director of NOAA's National Weather Service. "For the first time, a consistent standard of wind chill will be used by both Canada and the United States."
The new wind chill formula is the product of a year-long effort by scientists and wind chill experts from the academic community, and the U.S. and Canadian governments. The Office of the Federal Coordinator for Meteorological Services and Supporting Research created this Joint Action Group for Temperature Indices, which is chaired by the NWS. The goal of JAG/TI is to internationally upgrade and standardize the index for temperature extremes (e.g. Wind Chill Index).
In October 2000, scientists
began evaluating the previous wind chill formula and developed
plans for a standardized index among the meteorological community
for North America. This new wind chill formula was developed
after extensive analysis of the factors that impact wind chill,
using the latest advances in science, technology and computer
modeling to provide a more accurate, understandable and useful
model for calculating the dangers from winter winds and freezing
temperatures. The resulting formula was then tested using human
volunteers at the wind tunnel and climatic chamber of the Defense
and Civil Institute of Environmental Medicine in Toronto, Canada.
The new formula has been incorporated
into the latest software installed on the NWS Advanced Weather
Interactive Prediction System (AWIPS)
effective Nov. 1, 2001. In 2002, adjustments for solar radiation
(the impact of the sun) and for a variety of sky conditions (sunny,
partly sunny and cloudy) may be added to the calculation model.
The previous index has been used by the National Weather Service since 1973, and was based on science produced by Antarctic explorers in 1945.
The new wind chill index is available online.
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