Hi
I'm about to take my met exam at some point in the next couple of weeks. I have so far managed to get through almost all of my revision and doing well with my practice questions. However I've had a go at question 37 in the confuser which says:
"Given a surface temperature of +21 degrees celsius and a dewpoint temperature of +7 degrees celsius, at approximately what height will the base of cumulus cloud be found?"
So far I have been learning that:
DALR = 3 degrees per 1000ft
SALR = 1.5 degrees per 1000ft
Average ELR = 2 degrees per 1000ft
So to calculate cloud base you simply calculate the altitude where the DALR temperature reaches the dew point temperature. The problem is according the confuser explanation says "dewpoint decreases by 0.5 degrees / 1000ft so DALR is modified". The nearest answer is therefore 5500 feet.
I've never come across this in either the Thom or Pratt books so I'm confused by it!! Why would you need to modify the dewpoint temperature and why does it deacrease by 0.5 degrees per 1000ft? I'm totally confused and would really appreciate some help! Its the only part of met I just can't get at all
Thanks for any info you can offer in my hour of need
