Howard Neil wrote:
Martin Rowley wrote:

(PS ... this is covered in the FAQ page relating to frontal types ...
though admittedly not this particular example!)

http://homepage.ntlworld.com/booty.w...frontal_ex.htm


I was about to ask the same question and, no, it is not shown on that
FAQ page.

My apologies, Martin. I have just had another look at the FAQ and found
it in the bottom right hand corner (Z). I see that it is a convergence
zone.

--
Howard Neil