"K.P. Termaat" wrote in message . ..
I think your way of thinking is correct. I have an equivalent experience for
wooded areas. During the day they do not work well, but at dawn when the
environment is cooling down they give off their accumulated heat and produce
thermals.

Karel, NL


I expect 99% percent of those reading this will realize *dawn* was
probably a translation error, but just in case, I think you meant
*dusk* or evening.


Andy (GY)