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GLOSSARY
The below definitions have been greatly simplified in order to keep this section brief. We strongly
recommend that anyone who wishes to make use of these measurements refer to one of the many
excellent weather references available for a more in-depth definition. On the internet, visit www.
usatoday.com or www.noaa.gov. Or, locate the USA Today publication, The Weather Book. Please note
that any words in a definition printed in italics are themselves defined in this glossary.
Altimeter Setting
An aviation term for the local barometric pressure. Same as reference pressure.
Altitude
The distance above sea level. The Kestrel Meter calculates altitude based on the measured station
pressure and the input barometric pressure - or “reference pressure”.
Barometric Pressure
The air pressure of your location reduced to sea level. Pressure will change as weather systems move into
your location. Falling pressure indicates the arrival of a low pressure system and expected precipitation
or storm conditions. Steady or rising pressure indicates clear weather. A correct altitude must be input
for the Kestrel Meter to display barometric pressure correctly.
Declination
Also called variation, is the angle between magnetic north and true north. Declination is considered
positive east of true north and negative when west. Declination changes over time and with location.
