[Ref Understanding Weather & Climate, Books a la Carte Edition (6th Edition) #ISBN-13: 978-0321773227 #ISBN-10: 0321773225 CH 5 Atmospheric Moisture, Pilot’s Handbook of Aeronautical Knowledge, FAA-H-8083-25B Page 12-13]

Application of dew point – determine the height of the cloud base

Divide the temperature-dew point spread by the convergence rate (2.4ºC or 4.4 ºF), and multiply by 1000 –

Est Cloud base = (spread/2.4ºC)*1000 feet

Est Cloud base = (spread/4.3ºF)*1000 feet

*example: **Temperature 85F; Dew point 71F *

*[formula: F= (9C)/5 + 32]*

85 F = 29.4 C

71 F = 21.7 C

Spread = 29.4 -21.7 = 7.7 C

*Ans:* Est Cloud base = (7.7/2.4)* 1000 = 3208 feet ≈ 3200 feet