Skyscrapers and Thunderbirds - 9/27/19

I recently worked on  fun series of non-geocaching puzzles in a Labor Day Extravaganza,  which contained a super hard sudoku variant that you might like to check out in  this file, on the late page, called "Thunderbirds".  It was really tough but I managed to get through it in the end, due to having a little practice with a more basic form in this memorable puzzle, featured back in 2015:

Skyscraper Sudoku

Tomorrow we'll ...