Yeah, you've missed the point. Pretty much completely, in fact.
For one thing, this is a guide to the opening sentence, not the opening paragraph. More information to come in the opening paragraph can be assumed. The starters are simplistic and schoolish because this post is a lesson. They are to illustrate the mechanism.
To take your own paragraph, it honestly isn't very good. You've lost yourself in details, and twisted it into a knot in the process. So, starting with the concept, this is a ghost story. The environmental mood should be threatening and spooky. The sheets of rain and reduced visibility are certainly intense, but they aren't threatening unless your character has to go out and drive in it. Another problem is that rain has a symbolism of cleansing, rejuvenation, and rebirth - it's not spooky, and it certainly doesn't support the beginning of a ghost story (howling wind, thunder, and lightning, absolutely right - heavy rain, not so much). Then we come to the problems of sentences #2 and #4 - the first states that it's the sort of storm that hasn't been seen in ages, making it different. But then, having already established that the storm is different, in sentence #4 you add on a second "But this night was different," creating the knot. And only then do you get to the most important piece of information: there are ghosts.
It's true that a reader will often give you a full paragraph to hook them. But this doesn't make putting the actual story hook at the end of a paragraph a good idea. You get much better results if you use the opening sentence to hook the reader, and then the rest of the paragraph to draw them further in by adding details and information.
(As far as my own story goes, the dark tower isn't described in any detail in the opening sentence because it is almost completely irrelevant to the character and the story - it appears in the prologue and will never be seen again. The trope is invoked to inform the reader of a single thing: that The Destroyer is a dark lord in a fantasy story. What is important is the contradiction - this traditional, even cliched, dark lord is not acting like one. The rest of the prologue draws these contradictions out, adding details (such as descriptions of the tower, and the fact that he spends his days alone sitting on his throne) a bit at a time to build the picture. There are other reasons that it is left so vague and undeveloped, but you'll just have to read the story if you want to know more.)