If you want a strong Southern ocean:
- Place a single small landmass in the middle. This will help anchor the swirling water so that it doesn't swirl off balance, and get in its own way.
- Place a few pointy land masses that angle down any current that drifts northwards.
(eg South America, Africa, Australia)
- Two or more relatively large heat basins (eg, the Indian and Pacific oceans) that use the sun to cycle large amounts of current that help push the circulation in the southern ocean.
If you don't you'll get the equivalent of the northern ocean.
- No central landmass, causing the current to flow into its own path, reducing its own strength.
- Many relatively flat landmasses that make a ring, but more importantly are angled to deflect the current away from the pole.
- connection to oceans in such a way that the cycle pushes against, or simply pulls current strength from the ocean.
Going off on a tangent it looks like your wanting some extreme climate and variability.
If your after storms, the most violent storm periods in earth (geologically speaking) form when a clean band of ocean forms through the tropics. This causes the warm water to heat year round increasing the frequency/strength of strong weather. It also has the nice effect of caging in the northern/southern oceans own currents concentrating their own strength.
Also be aware that this kind of event tends to throw the oceanic ecosystems into disarray, as cooler water species cannot cross the equator easily, hot water is much less oxygenated and tends to create massive dead zones, and depending on the oceans recent history, it can release copious amounts of green house gases strengthening global warming trends. Needless to say there will be no reliable fishing in such a world.
Take a look at the Gondwana/Lurasia super-continent split for a recent example in earth history.
Conversely if you get a continent or near perfect large continent linking north to south it diverts most ocean currents warming the poles and cooling the tropics, producing an overall more stable climate. You can still get massive storms particularly if you have a giant pacific ocean/indian ocean style where the ocean currents are mostly forced to cycle. Couple that with a giant mountain range relatively close to the coastline, this will trap massive weather events along the coast causing massive amounts of rain, and flooding. While turning the rest of the continent into a relatively barren and unforgiving desert. Take a look at Australia or India for an example.
Also do not forget other events such as volcanism, or world forests for playing hell with the weather.
- The Siberian Lava Traps are firmly believed to have shifted the climate during the great Permian Extinction. They released so much CO2, Sulfur, and other chemicals, particular small particles that it both cooled and heated the atmosphere on different timescales. This disrupts weather patterns, usually allowing larger storm weather systems to strengthen as relatively strong stable weather patterns are weakened.
- The Carboniferous Period was so heavily populated by trees, and lacked a good decomposition cycle. This caused an atmosphere relatively devoid of CO2 and very rich in Oxygen, producing a large net difference in static charge. This resulted in powerful lightning storms, and fireballs in the sky, as relatively rich pockets of oxygen were combusted with other atmospheric elements during those lightning strikes.