> I use the forecast put out by weather.gov that's supposedly tailored to the square mile because it gets the 12 hour forecast right about 40% of the time.

Unfortunately, this is an example of false precision. The highest resolution numerical forecasts run by NOAA have a grid of about 3km, already coarser than your one-square-mile "tailored" output. The effective resolution of numerical weather models is also 2-3 times coarser than their grid spacing (because of numerical diffusivity and similar effects).

What you're seeing isn't a "tailored" output, but instead an interpolated result from a coarser grid.

Forecasting of very high-resolution effects is the subject of active and ongoing research, but unfortunately popular meteorology does not do a good job of discussing current limitations.

Look at the confusion in this set of comments, for example, about what degree of forecast error is normal/acceptable.