This is much to generalized to mean anything, as "California" does not have just a single type of weather each day, nor does "Texas." In fact, both states have some "wet" climates and both states have deserts. The climate of Houston is different than that of Dallas, and both are far different from that of the desert of West Texas. Same with California, with Death Valley, with it raining there maybe once a year, and then Eureka, which only has 179 sunny days every year.
So, if you were in So Cal (which from the comment, I'm guessing you were), then you are basically part of the desert climate and only get 14" of rain a year, just that the ocean moderates the weather and provides more rain that areas further from the coast. So, if you were in Houston -- a sub-tropical climate with its weather affected by the Gulf -- you see about 45" of rain during the year and very humid conditions even when sunny in the summer. It is also worth noting that Dallas is further North than Los Angeles (Dallas and San Diego are fairly close to the same latitude) and Northern California, such as Eureka, is further North than New York City.
Having said that, I don't know what you are talking about regarding poor weather forecasts. Now, if you want to compare weather forecasts of 3 days or more, yes, there is often a fair amount of "guesswork" as meteorologists don't have all the information (and it seems to be getting worse under the Trump administration, such as blocking access to weather data from the Defense Meteorological Satellite Program) to fully predict storms. At the same time, as a Senior Citizen, I've seen huge improvements to weather forecasting in my lifetime. My experience in most places is that while you have to take forecasts 3 days or more with a grain of salt, once you get within 48 hours the forecasting tends to be very accurate; with the primary issues not being what the weather is but that they sometimes miss on the severity. At the same time, it was amazing in Texas to have weather apps, rather accurately, inform me when it would start raining and how hard the rain should be.
Which gets us back to the point, within the key time period , the last 24 hours, the forecasting was accurate. They called the flash flood warning 12 hours before the storm hit. They called the flash flood watch over an hour before the heavy rain started (which is why the camp delayed an hour). There are times you can be critical, such as the time in Houston when they claimed there would be a hurricane and the city evacuated, but then the storm hit Beaumont instead and, being on the West of the storm, it wasn't even much rain in Houston. OTOH, far better to use caution in projections, get people out of the city early, rather than think it isn't going to hit and then have people stuck on freeways trying to leave while the hurricane is coming on shore.
I'll also note, one of the issues in Houston, is that most forecasts use a lot of historical data. That doesn't work for Houston because it is built on a swamp that has now been cemented over for miles. Historically, the water would seep into the ground which, at least until the ground got saturated (and because of the swamp, the ground could take a lot of rain), helped to prevent flooding. Now, the ground can't hold much water anymore, which is why Houston had 3 "500 year" storms (with lots of flooding) in about a 3 year period.