I was wondering about "covering x percent of surface", so I looked it up:
|Planet Surface Area (km²)|Storm Surface Area (km²)|Storm covers % of planet
:--|--:|--:|--:
**Earth**|510.072.000|70.686|0,01386
**Jupiter** (red spot minimum)|61.419.000.000|904.778.684|1,47313
**Jupiter** (red spot maximum)|61.419.000.000|1.759.291.886|2,86441
So even if we assume the smallest observed dimensions of the great red spot (24.000km by 12.000km), the storm on Jupiter is ~100x bigger in relation to its size than Hurricane Matthew is compared to Earth.
If we take the biggest great red spot dimensions (40.000km by 14.000km), the factor rises to ~200x!
It was surprisingly hard to find a consistent value for the size of hurricane Matthew, so if someone has a better source, I will adjust the calculations.
But unless they are off by two orders of magnitudes, it won't change the outcome.
replydetachattach picture