Weather Forecasting Description and Limitations
In general, if the rate of change of pressure increases, the weather is generally improving (sunny to partly cloudy).
If the rate of change of pressure decreases, the weather is generally degrading (cloudy, rainy ｏｒ stormy).
If the rate of change is relatively steady, it will read partly cloudy.
The reason the current conditions do not match the forecast icon is because the forecast 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.
However, it is still an interesting educational tool for learning why the weather changes.
The National Weather Service have many tools at their disposal to predict weather conditions, including weather radar, weather models, and detailed mapping of ground conditions.