FREEZING LEVEL CALCULATION:
CLOUD BASE CALCULATION:
But wait does air cool at 3.5F or 5.4F per 1,000ft??
Per FAA (and Jeppesen) "A standard temperature lapse rate is when the temperature decreases at the rate of approximately 3.5 °F or 2 °C per thousand feet up to 36,000 feet"
Use this to calculate freezing level. Ok, no big deal.
Use this to calculate freezing level. Ok, no big deal.
CLOUD BASE CALCULATION:
"As moist, unstable air rises, clouds often form at the altitude where temperature and dew point reach the same value. When lifted, unsaturated air cools at a rate of 5.4 °F per 1,000 feet and the dew point temperature decreases at a rate of 1 °F per 1,000 feet. This results in a convergence of temperature and dew point at a rate of 4.4 °F. Apply the convergence rate to the reported temperature and dew point to determine the height of the cloud base."
Ok, easy enough.
Ok, easy enough.
But wait does air cool at 3.5F or 5.4F per 1,000ft??
