What is the approximate base of the cumulus clouds if the surface air temperature at 1,000 feet MSL is 70°F and the dewpoint is 48°F?

To determine the approximate base of cumulus clouds, you can use the temperature and dew point values provided. The base of cumulus clouds is generally found where the rising air cools to the dew point temperature, which is the point at which the air becomes saturated and can no longer hold additional moisture.

In this scenario, the surface air temperature at 1,000 feet MSL is 70°F and the dew point is 48°F. The most common rule of thumb for estimating the base of cumulus clouds is that for every 1,000 feet of altitude, the air temperature decreases by about 2 to 3 degrees Fahrenheit.

Starting from the ground level of 70°F, if we assume a temperature decrease rate of approximately 2 degrees for each 1,000 feet of ascent, we need to calculate how high the air must rise for it to cool down to 48°F (the dew point).

The temperature difference is:

70°F (surface temperature) - 48°F (dew point) = 22°F

Using a cooling rate of about 2 to 3 degrees Fahrenheit per 1,000 feet, a drop of 22 degrees would suggest cloud formation occurs after an ascent of around 7,