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Rain
Vantage Pro2 incorporates a tipping-bucket rain collector in the ISS that
measures 0.01'' for each tip of the bucket. A metric adapter can be installed to
measure 0.2 mm for each tip of the bucket.Your station logs rain data in the same
units it is measured in and converts the logged totals into the selected display
units (inches or millimeters) at the time it is displayed. Converting at display
time reduces possible compounded rounding errors over time.
Four separate variables track rain totals: “rain storm,” “daily rain,” “monthly
rain,” and “yearly rain.” Rain rate calculations are based on the interval of time
between each bucket tip, which is each 0.01'' rainfall increment or 0.2 mm.
Barometric Pressure
The weight of the air that makes up our atmosphere exerts a pressure on the
surface of the earth. This pressure is known as atmospheric pressure. Generally,
the more air above an area, the higher the atmospheric pressure, this means that
atmospheric pressure changes with altitude. For example, atmospheric pressure
is greater at sea level than on a mountaintop. 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 Vantage Pro2 measures
atmospheric pressure. When you enter your location’s altitude in Setup Mode,
the Vantage Pro2 stores the necessary offset value to consistently translate
atmospheric pressure into barometric pressure.
Barometric pressure also changes with local weather conditions, making
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
purposes, however, the absolute barometric pressure value is generally less
important than the change in barometric pressure. In general, rising pressure
indicates improving weather conditions while falling pressure indicates
deteriorating weather conditions.
Solar Radiation
What we call “current solar radiation” is technically known as Global Solar
Radiation, a measure of the intensity of the sun’s radiation reaching a horizontal
surface. This irradiance includes both the direct component from the sun and the
reflected component from the rest of the sky. The solar radiation reading gives a
measure of the amount of solar radiation hitting the solar radiation sensor at any
given time, expressed in Watts/sq. meter (W/m
2
). Solar radiation requires the
solar radiation sensor.