"Why would you want to check destination weather after you have taken off?"
I dunno, maybe a small detail like the weather at the destination has gone below minimums, or the only runway has been notam'd closed because somebody landed one gear up. Usefull stuff to know I'd say....
By the way, shouldn't it be;
T erminal
A erodrome
F orecast
as opposed to
T erminal
A rea (?)
F orecast
I think some people are confusing the TAF with an A rea F orecast
(FA)