For As Far Back As I Can remember,

Jupiter has always had a red spot,

 a huge one, and has had for a few hundred years,

the Great Red Spot's dimensions are 24–40,000 km × 12–14,000 km,

perhaps this will convey it's size better, that is what the red spot would like if the Earth was dropped into it, we ll it looks like this huge storm could disappear in some of our lifetimes, 

NASA's $1 billion Juno probe took stunning photos of the Great Red Spot in July 2017, the closest images we've ever gotten of the giant tempest. Scientists were floored by the level of detail beamed back by the spacecraft, but here is the thing, it is thought that within 10 or maybe 20 years the spot which is actually a storm will be gone forever, Glenn Orton a lead Juno mission team member and planetary scientist at NASA JP, why Jupiter's storms last so long, "They don't, at least not all of them," Orton said in an email. "Think of the GRS [Great Red Spot] as a spinning wheel that keeps on spinning because it's caught between two conveyor belts that are moving in opposite directions. The GRS is stable and long-lived, because it's 'wedged' between two jet streams that are moving in opposite directions." in the late 1800s, the storm was perhaps as wide as 30 degrees longitude, Orton said. That works out to more than 35,000 miles — four times the diameter of Earth. When the nuclear-powered spacecraft Voyager 2 flew by Jupiter in 1979, however, the storm had shrunk to a bit more twice the width of our own planet, "Now it's something like 13 degrees wide in longitude and only 1.3 times the size of the Earth," he said. "Nothing lasts forever." How so very true.