I'm currently working on a story set in a planet whose rotation period lasts around 24 years (Earth years, or 8766 days). This planet orbits at more or less 0,75 AU from a K-type star, and the translation period lasts about 365 days. It is similar in size and mass to the Earth except it has no tectonic activity. Due to slow rotation, water tends to flow to the poles, leaving a ring-like supercontinent between the 40th parallel north and the 40th parallel south. For sake of simplicity lets say its axial tilt is 0º. The temperature in the day zone is 150ºC (302ºF) and -150ºC (-238ºF) in the night zone (although these numbers can change as long as there is impossible for humans to live in those zones).
In tidally locked planets we can expect huge hurricanes and storms in the day side as water evaporates, strong winds from the night zone to the day zone and frozen water storing on the night side, and I think these conditions may be similar to my planet, but not the same.
Since this planet spins (very slowly, but it spins), I see the sunlight sort of like a "heat ray" (to put it in plain words), from the surface perspective. This heat ray, with the diameter of a whole hemisphere, burns the land and evaporates the water, creating storms, as it slowly moves on eastward to the temperate zone. But in the other edge of the ray, the land reclaimed by the temperate zone is already burnt and dry, so hot air ascends, but it has no moisture to form rain clouds. Likewise, as the night side moves on, it freezes the dry land, but as it retreats, the frozen water stored in it melts by action of the day side.
I assume there would be a "drier" convection cell in the temperate stripe moving sunward, and a "wetter" convection cell in the temperate stripe moving nightward. This would be the diagram:
As the sun heats and boils the water, this hot humid air would flow in every direction to fill the void, so I would expect humid winds traveling through the poles, losing water and then regaining it from the ocean and creating new rain clouds. This could moderate the weather in the temperate zones and supply water tho the drier stripe moving sunward. I'm thinking that maybe, as the continent get cooler faster than the ocean, we could expect a phenomenon like the monsoon in India or El Niño in South America.
In regard to the stripe moving nightward, I would expect heavy rainstorms, violent winds, and in general a more inclement weather than in the sunward stripe. Also, colder water released by the night zone would cool down the continent, but maybe the sun moving on and boiling the oceans could regulate the temperatures.
In the poles the climate would be calmer, but since they're covered by water, we couldn't expect but sealife.
I think although it might seem complex, it's actually a very simple climate pattern. The planet doesn't have tectonic plates, so it lacks high mountains that would deflect winds. The planet has an orogeny produced mostly (if not completely) by meteorite collisions in a distant past. Also, the continent shape would be pretty regular, with few lakes, inner seas or pronounce gulfs.
I would like some feedback from you, guys. I don't know if I'm missing some crucial points, maybe something I'm not taking into consideration about oceanic currents, albedo, magnetism, satellites, atmospheric composition... you name it. The main goal of all of this is creating a planet though hostile, could harbor human life (and as scientifically accurate as possible!).
Human life in this planet would have developed naturally, evolving from a life form to another until reaching human species. All of the exposed here may be changed, but my only requirements are:
Human life. Normal, Earth-like humans. They wouldn't be strictly humans since they are not exactly Earth-born and raise Homo sapiens, but they should be similar to humans in all aspects.
A day of 24 years (or more). It would be similar to be tidally locked but it’s NOT tidally locked. One hemisphere of the planet would be exposed to the sunlight for a long period of time, while the other is dark, but it would rotate slowly so life could exist, but animals and people would have to be always migrating. I want them to have to constantly travel and face the risks of this hostile environment.
Uninhabitable day and night. Temperatures can be different from 150ºC and -150ºC. They may be more extreme if needed.
About axial tilt, distance to the star, heat/size of the star, satellites orbiting the planet or other celestial bodies, we can touch up all these things. But please bear in mind those three requirements.
Thank you very much!!
PD: If something isn't clear enough please tell me and I would be glad to clarify it!