At what approximate altitude above the surface would the base of cumuliform clouds be if the surface air temperature is 86°F and the dew point is 30°F?

To determine the approximate altitude above the surface at which the base of cumuliform clouds forms, it's important to use the relationship between temperature, dew point, and the rate at which air cools with altitude. The key concept here is that clouds form when air rises, cools, and reaches its dew point temperature.

The dew point temperature (30°F) indicates how much moisture is present in the air. A higher difference between the surface temperature (86°F) and dew point signifies that the air is relatively dry, meaning that clouds will form at a higher altitude. The temperature lapse rate is typically around 3°F per 1,000 feet in the lower troposphere.

To calculate the height where condensation occurs (the base of the cumuliform clouds), the following formula can be applied:

1. Find the temperature difference:

• Surface temperature = 86°F

• Dew point = 30°F

• Temperature difference = 86°F - 30°F = 56°F

2. Approximate how far this temperature difference corresponds to altitude using the lapse rate:

• For every 3°F, the altitude increases by approximately 1,000 feet.

• Therefore, 56°F would roughly translate to: