Not actually sure if this will fit what you had in mind, but, what about having the planet just turn slowly?
I mean, days are warmer than nights, and sunny days warmer than cloudy ones, nice and simple - so if the sun is in the sky for longer days, the days should get a lot hotter with more sunlight and radiation, and the nights a lot cooler, since it's longer until the sun warms them up again. The more rapidly the planet turns, the more the temperature would be equalized, I think, and the slower it turns, the hotter the day and colder the night (like Mercury, though your planet will have an atmosphere and so will not be so extreme)
So, the idea that popped into my head as a starting point was a day about three times as long as our day. The middle third of that day would probably be hotter, and the middle third of that night probably colder, than probably even the hottest day and coldest night of the equivalent area on earth - since the area won't have cooled down or heated up in the meantime. Diurnal temperature variances can range from a few degrees (4*C), to more than a hundred degrees (102*C, granted that is a world record), depending on landscape and season, but someplace like a desert would have the highest variations. One example given of the diurnal variation of a low lying plain was 30*C - which would increase a lot with longer days, since a day three times as long (with no other differences) could mean a gain and loss of 90*C, and could also mean more as the rise in temperature during the extra hours of sunlight is heating an area still warm from the hours equivalent to our day, with no chance to cool off first. Likewise the night would have more time to loose heat, and would likely get colder the longer it was out of sunlight.
A couple other thoughts - if the temps get higher every day and cool a lot more every night, then any plant that survives would have to be adapted to those temperature variations - it might favor vegetation that is more desert-like (since those adaptions work on our world, in similar conditions). And areas that are more desert-like experience more diurnal temperature variations, since the vegetation doesn't hold the temperatures as well, so it could be a cycle tending towards desertifying any flat areas. If the world is a little warmer than ours (perhaps by being closer to the sun, as AndyD273 suggested), or a little drier, or even a little smoother that might reduce the frequency other ecosystems (like rainforests, the other adaption to hotter temperatures) to a much less observable level. So where we have deserts might be mostly uninhabitable, where we have plains would be deserts, forests would likely be plains (and eventually adapt towards deserts), rainforests would be more like temperate forests (after adapting to colder nighttime temps), and so on.
Second point, the violent storms make sense in a world with high temperature variations - the atmosphere would try to equalize the extreme temperatures from the day side to the night side, meaning violent winds that can easily play into your giant electrical sandstorms.
I'm not entirely sure about the details of this, but the size of your planet might play a role as well - a larger planet might have more thermal mass to equalize temperatures, and a smaller might not be able to hold onto extra heat, and so have more extreme temperatures. Also, a planet with a warmer core might be warmer overall (as you wanted a hot planet), but it might also be less prone to temperature extremes, since that inner heat could keep the temperature from varying as much between day and night. I know less about this, though, take it as a suggestion rather than a fact.