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GroWeather System Overview
Page 10 GroWeather Manual
Rainfall
The GroWeather provides two separate registers for tracking rainfall totals.
One is referred to as “daily” rainfall and the other is referred to as “total” rain-
fall. In truth, these registers can be used to record rainfall over any period of
time you desire. The “daily” register can be cleared daily using the AutoClear
function (see “AutoClear” on page 13) to provide true daily rainfall totals or
you may clear it manually every few days, after a storm, at the end of the
month, etc. The total rainfall amount must be cleared manually; how often you
clear the register determines what period of time its rainfall total reflects. The
GroWeather also calculates the rate of rainfall by measuring the interval of time
between each .01” or .2 mm rainfall increment.
• “Daily” Rainfall (Alarm: High) (AutoClear)
• Current Rate of Rainfall in inches or millimeters per hour
• Total Rainfall
• High Rate of Rainfall with time and date of occurrence (AutoClear)
Barometric Pressure
The weight of the air which makes up our atmosphere exerts a pressure on the
surface of the earth. This pressure is known as atmospheric pressure. Gener-
ally, the more air above an area, the higher the atmospheric pressure, which
means that atmospheric pressure changes with altitude. To compensate for this
difference and facilitate comparison between locations with different altitudes,
atmospheric pressure is generally adjusted to the equivalent sea-level pressure.
This adjusted pressure is known as barometric pressure. In reality, the
GroWeather measures atmospheric pressure. When you enter the barometric
pressure for your location (see “Entering Barometric Pressure” on page 37), the
GroWeather stores the necessary offset value to consistently translate atmo-
spheric pressure into barometric pressure.
Barometric pressure also changes with local weather conditions, which makes
barometric pressure an extremely important and useful weather forecasting
tool. High pressure zones are generally associated with fair weather while low
pressure zones are generally associated with poor weather. For forecasting pur-
poses, however, the absolute barometric pressure value is generally less impor-
tant than the change in barometric pressure. In general, rising pressure
indicates improving weather conditions while falling pressure indicates deteri-
orating weather conditions.
• Current Barometric Pressure (Alarm: rate of change)
• Recall of Previously Stored Barometric Pressure Value, with time and date of
stored value (AutoClear)
• Trend of Barometric Pressure (rising, falling, steady) over previous one hour