A Skew-T would give you the temperature-dewpoint spread at various
locations...seems to me that there should be a number of reporting points in
the Bay Area, although you could do it by lat-long. An altitude where the
T-DP exceeds 3 degrees (maybe, 5 would be better) should be cloud-free.

Go to http://rucsoundings.noaa.gov/, read the tutorials, etc at the bottom
(especially the article from "The Front"), and have at it. Then go to
www.chesavtraining.com to get acquainted with Scott Dennstaedt,
meteorologist/CFII; buy his CD program on Skew-T for a real education.

Scott participates in the AOPA and Pilots of America forums.

Bob Gardner

"Terence Wilson" wrote in message
...
Here in the San Francisco Bay Area we've had coastal clouds in the
mornings with ceilings in the 1000-2000 range recently, 10-20 miles
west of Oakland the clouds dissipate completely. I was wondering
weather there exists a reliable way of determining the cloud tops
(other than PIREPs).

TIA