Applying for Tier 1 from different country

[Jammin]

Hello,
I'm an Indian national working in the US and intend to apply for Tier 1. But I am planning some extensive travel through South America in-between my move from US to UK. Is it possible to apply for Tier 1 from a country that is not your current residence, like say Brazil? Once I leave the US, my work visa will be canceled and I wont be able to return to apply for Tier 1, without getting a tourist visa first.

Just asking if there is any regulation that you have to apply from your country of current residence.

I will keep my maintenance funds current and figure out all the proper paper work, but wanting to know if it's even possible in the first place.

I know this doesn't sound the normal route, but I have my reasons for my travel plans (helping out a charity).