Living in California, I find the weather a lot more complicated than when I was living in a much flatter and consistent area of the country. Just within my city the variance is so large that any forecast that just says "Los Angeles" is just an average that doesn't exist in reality at all. In Marina del Rey it could be 60, cold, grey, windy, even raining, then you go seven miles northeast to hollywood and its sunny, 85, hot, without a cloud in the sky, no cool ocean breeze, then you go through the cahuenga pass and in a 10 minutes drive the temperature goes up another 10 degrees by the time you are in north hollywood. Then if the winds decide to shift and you get some Santa Anas blowing in, everything can turn on its head fast and its hot in marina del rey even at night.
Even with a storm moving directly above it could do remarkably different things whether you live in a flatter side of town or one on a hillside, which usually sees precipitation and even hail or sleet along with colder temps while it might remain bone dry in the flatter parts.
Accurate weather estimations for some places needs a very robust understanding of local topology, seasonal winds, and data, lots of data, from sensors that aren't there in enough quantities and in enough places to capture what is actually happening over varied terrain and changing conditions. I found localized apps like darksky very accurate in the midwest where weather is uncomplicated to model beyond occasional things like lake effect snow (which seemed to be well understood), but not very useful in Los Angeles where you practically need your own hardware to actually quantify what the weather is where you are at in your particular canyon today.
Even with a storm moving directly above it could do remarkably different things whether you live in a flatter side of town or one on a hillside, which usually sees precipitation and even hail or sleet along with colder temps while it might remain bone dry in the flatter parts.
Accurate weather estimations for some places needs a very robust understanding of local topology, seasonal winds, and data, lots of data, from sensors that aren't there in enough quantities and in enough places to capture what is actually happening over varied terrain and changing conditions. I found localized apps like darksky very accurate in the midwest where weather is uncomplicated to model beyond occasional things like lake effect snow (which seemed to be well understood), but not very useful in Los Angeles where you practically need your own hardware to actually quantify what the weather is where you are at in your particular canyon today.