How do you estimate the base height of a cloud using dew point and temperature?

Estimating the base height of a cloud involves using the temperature and dew point to determine the dew point spread, which is the difference between the air temperature and the dew point temperature. The correct method is to take the temperature, subtract the dew point, and then multiply that difference by 400 to calculate the height in feet.

This calculation is based on the principle that as air temperature decreases to the dew point, condensation occurs, resulting in cloud formation. The larger the dew point spread, the higher the cloud base tends to be because the air needs to cool more in order to reach the dew point and condense into clouds. Therefore, the formula effectively converts this spread into a height measurement by multiplying by 400, which provides a reasonable estimation of how high the cloud base will be above ground level.

Using temperature and dew point properly is essential in aviation as it helps pilots assess weather conditions and make informed decisions regarding flight safety and operations.