Beware! The Thom book is wrong on this.
The lapse rate for cloud formation is 2.5deg/1000ft.
The DALR is 3.0deg/1000ft and the Dewpoint Lapse Rate is 0.5deg/1000ft. DALR-DPLR = Lapse Rate for cloud base calc (3.0-0.5=2.5). This is what the exam will expect you to use.
Last edited by High Wing Drifter; 14th February 2003 at 16:08.