You've only watched two episodes, though? :p
(And the pilot doesn't even follow the pattern.)
Every episode starts with the Sheriff talking to someone or doing something (this is oftentimes how they work his daughter into the episode, since she usually serves no purpose otherwise). Someone will say something seemingly unimportant or something seemingly unimportant will happen.
Then something shocking happens! I don't know, it's raining puppies or something.
~Opening credits~
There's a scientist who's been researching animal rains, so they go and interview him, but it turns out he's not behind the puppy rain, but he points them in the direction of someone else who points them in the direction of someone else.
And then it turns out it was the first guy after all. So they go to him again, and he explains that he didn't mean to make it rain puppies but now he's lost control of the rain and soon they'll all drown in furry little bundles of joy. Oh no!
Just when it looks like all hope is lost, the Sheriff recalls that seemingly unimportant detail from the opening scene and uses it to save the day.
~The end~