Bill J wrote in message ...
So, the last chance to land before the TS got heavy was coming close.
When about 15 miles from this new "alternate" I told controller I wanted
to change destination. I expect a vector to the final, and I was needing
to start descent. Nothing happened. Finally when maybe 5 miles out, and
way to close to get a vector, controller quizzed me with "I need to know
what is the reason for the change in destination??"

First I'd just like to comment that you don't have to leave it
to 5 miles out. If wx is closing in and you want a vector to
the approach, ask for it all. Say "I need to divert to xxx due
to deteriorating weather, request immediate descent to yyy altitude
and vectors to final approach course for zz approach"

Of course, the ATC facility in question may not be able to give
you vectors.

Second just as another data point, we were flying from the St Louis
area to HOT last weekend, and overheard someone asking KC Center to
amend their destination to KC Downtown. The controller came back
with "we're required to put down a reason for any change", the pilot
responded "Downtown has better weather" and apparently that sufficed.

So now I'm wondering if there's some new security procedure where
ATC is required to play TSA Cop and regard pilot requests to change
destination as potential security breaches which must have a good
reason? (as if someone intent on harm can't equip himself with a
plausible-sounding good reason)

Any ATCS know?

Cheers,
Sydney