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5.6.4
Storm threshold indicator
The storm threshold (the negative rate of pressure change signifying a storm is expected) can be
adjusted by the user from level 3 to level 9 (the default level 4).
When negative rate of change of pressure is exceeded for 3 hours, the storm warning indicator will be
activated, and the clouds with rain icon and tendency arrows will flash for 3 hours indicating the storm
warning feature has been activated.
5.6.5
Pressure threshold setting
The pressure threshold (the negative or positive rate of change of pressure signifying a change in the
weather) can be adjusted by the user from level 2 to level 4 (default level 2).
The lower the level pressure threshold setting, the higher sensitivity for weather forecast changes.
Locations that experience frequent changes in air pressure require a higher setting compared to
locations where the air pressure is typically stagnant.
5.6.6
Pressure Graph
Note:
The weather station bar graph flashes from left to right to prevent screen burn in. This
feature cannot be turned off.
The pressure graph displays the barometric pressure for the last 24 hours. Each bar represents three
hours.
6.
Glossary of Terms
Term
Definition
Absolute Barometric
Pressure
Relative barometric pressure, corrected to sea-level. To compare
pressure conditions from one location to another, meteorologists correct
pressure to sea-level conditions. Because the air pressure decreases as
you rise in altitude, the sea-level corrected pressure (the pressure your
location would be at if located at sea-level) is generally higher than your
measured pressure.
Accuracy
Accuracy is defined as the ability of a measurement to match the actual
value of the quantity being measured.
Hecto Pascals (hPa)
Pressure units in SI (international system) units of measurement. Same
as millibars (1 hPa = 1 mbar)
Hygrometer
A hygrometer is a device that measures relative humidity. Relative
humidity is a term used to describe the amount or percentage of water
vapor that exists in air.
Inches of Mercury (inHg)
Pressure in Imperial units of measure.