Orion 420 Weather Station
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Columbia Weather Systems, Inc.
Tables and Formulas
Wind Chill Chart
In 2001, NWS implemented an updated Wind chill Temperature (WCT)
index. The change improves upon the former WCT Index used by the
NWS and the Meteorological Services of Canada, which was based on
the 1945 Siple and Passel Index.
In the fall of 2000, the Office of the Federal Coordinator for
Meteorological Services and Supporting Research (OFCM) formed a
group consisting of several Federal agencies, MSC, the academic
community (Indiana University-Purdue University in Indianapolis (IUPUI),
University of Delaware and University of Missouri), and the International
Society of Biometeorology to evaluate and improve the windchill formula.
The group, chaired by the NWS, is called the Joint Action Group for
temperature Indices (JAG/TI). JAG/TI's goal is to upgrade and
standardize the index for temperature extremes internationally (e.g. Wind
chill Index).
The current formula uses advances in science, technology, and
computer modeling to provide a more accurate, understandable, and
useful formula for calculating the dangers from winter winds and freezing
temperatures.
