[Somes J (OP)]

Hi. I'm planning to use an all-ocean planet as a setting in a science fiction story, and I was wondering, what would the effect of an absence of continents be on the planet's weather?

The planet is something like 98% water-covered, its only land is a number of islands, mostly small, the largest are comparable to the major Japanese or Carribean islands. It's otherwise relatively Earth-like, although somewhat warmer (ice-free poles).

One thing I'm curious about, I've read speculation that an all-water planet might develop very powerful semi-permanent hurricanes, like you see on gas giants, since there's no land for them to break against. Don't hurricanes follow general large-scale atmospheric circulation patterns which eventually take them to higher lattitudes, where they dissipate because the water is cooler?

[CliffordK]

Many of the planets (including Earth) have some gnarly polar cyclones.

Many tropical cyclones dissipate at sea on Earth.  However, it is likely that the continents affect the direction of the Jet Streams here on Earth.  Without continents, the air circulation patterns would likely follow a much more circular path...  and that might help maintain the storms as you mention.

There would certainly be other influences including the length of day, and the day/night temperature differential.