What is the obvious sign that the end (Joel 2:31),(Matthew 24:29)(Revelation 6:12)(Zechariah 14:1-3)(Revelation 16:14-16)?
The obvious sign is what is happening now, which is the gathering of all the nations against "Jerusalem" (Zechariah 14:2 & Revelation 16:16). What will be the consequences? "Jerusalem" will be "captured" (Zechariah 14:2) and there will be the "great earthquake", and "huge hailstones, about one hundred pounds each, came down from heaven upon men". Artillery shells can be weigh around 100 pounds each, such as a 155 mm artillery shell, or the individual war heads of a multiple warhead missile can also weigh around 100 pounds each.
Shell (projectile) - Wikipedia As for the "great earthquake", well, the super volcano, located under Yellowstone, has had around 2400 tremors in the last couple of months, and Japan is issuing warnings about an upcoming large earthquake expected in the near future. What can one do, well, a volcano generally starts with heat and fire, but ends up in a sort of nuclear winter, whereas the sun is blocked out and everything freezes. A similar instance is the Yucatan comet explosion, whereas anything anywhere close is either vaporized or cooked at the temperatures near that of a pizza over, and later, the skies are darkened and you get no sun and extreme cold. Apparently, the small mammals that lived in the ground and eat seeds were able to survive, whereas the large reptiles all died. Happily, the time will be "cut short" for the "elect" or no one would survive (Matthew 24:22).