Always thunderstorms

No matter what i do every few minutes a thunderstorm
i doubt that it works as intended because it started in 1.8
/weather clear 999999 the weather clears and starts a thunderstorm after 2-5 minutes.
/toggledownfall does the same like /weather

I have added screenshot which shows 5 minutes of playing

I don't know if this issue is very important but to me it is annoying.

also 2 thunderstorms have started since i started typing.