It is about as effective as watching channel five local news. Those predictions are often OK for Cleveland and east and west along the lake but often don't cover Akron and beyond. The radio weather channel carries forecasts which are much more reliable for areas further from the lake. I think that the short term forecasts are amazingly good. If they predict 42 degrees for the morning temperature, it will be right on most of the time and almost never off very much.
Rain gets a little bit more vague.
Generally the announcer manages to flesh that out a bit, however. The satellite pictures are terrific in understanding what is happening and sometimes you can see why the forecast might be iffy. Short term forecasts are very good. Five day forecasts are a little iffy. Seasonal projections are little better than guesses, but the equations keep being enhanced and maybe someday.