There's an explanation - having lived there I've seen first hand how the first rain of the season (and there is a rainy season) causes havoc because the windshield wipers, now being used for the first time in 6-9 months or more are all rotted usleless due to the overhanging smog and the rain brings up the slick grease on the roads causing a lot of slipping and sliding. It's funny cuz there's a run on wiper blades at Pep Boys. Also, there is the fear that if it ramps up, especially after a particularly bad fire season which burns away all the brush on hillsides, a lot of rain creates unimpeded flooding. I remember one winter that literally cemetery bodies were uprooted and floating down hills in Sunland and LaCrescenta. So yeah it's funny but it's also a reality and portent of possible things to come.
Dear Math, please grow up and solve your own problems, I'm tired of solving them for you. -Anon