Ambient Weather WS-YG720-THERMOMETER Replacement Thermometer for WS-YG710S-G and WS-YG720

1. It is highly advisable to lightly tap the glass near the center brass knob with your fingers before taking a barometer reading. The light tap will overcome any friction that may affect accurate hand readings, especially during periods of slow atmospheric changes. The Coast Guard has informed us that tapping the barometer is even required on the most expensive aneroid barometers, because the mechanism is made deliberately “stiff”.
2. Make sure you have calibrated the barometer to match the local airport. There is a discussion here:

   Relative Barometric Pressure Does Not Match Official Source.

3. If you live at high altitude, your barometer may be out of range (reads low all of the time).Since barometric pressure is significantly affected by altitude (and to a lesser extent, changes in weather), the barometer must be calibrated to sea-level to offset altitude effects.If your altitude exceeds the measurement range of the sensor mechanism, the barometer can not be adjusted to compensate for your altitude effects. Most sea-level barometers operate up to 3,000′. You will need to purchase a barometer that is designed for higher altitude conditions.

“Note: The text / icons on the face of the analog barometer are for reference only. The needle will NOT move from Stormy to Dry during normal barometric pressure events.”

Barometers forecast weather based on rate of change of pressure. This does not predict what is happening outside, but rather, if the weather will change in the next 24 to 48 hours due to changes in barometric pressure.

In general, if the rate of change of pressure increases, the weather is improving (sunny). If the rate of change of pressure decreases, the weather is degrading (cloudy or rainy). If the rate of change is relatively steady, it will read partly cloudy or partly sunny (depending on the type of weather station).

The reason the current conditions do not match the forecast icon is because it is a prediction 24-48 hours in advance. In most locations, this prediction is only 70% accurate and it is a good idea to consult the National Weather Service for more accurate weather forecasts. In some locations, this prediction may be less or more accurate.

The National Weather Service (and other weather services such as Accuweather and The Weather Channel) have many tools at their disposal to predict weather conditions, including weather radar, weather models, and detailed mapping of ground conditions.  Thus, these forecasts are significantly more accurate then forecasts based on rate of change of pressure.

You will need to give the weather station enough time to predict changes in weather. This can take up to 7days, depending on where you live. Also, make sure you have calibrated the barometer:

Note: Barometric pressure readings, under normal conditions, only fluctuate between 1-1.25 inHg per day”. Not +/- 1-1.25