hmm, I must admit I am lucky because even in heavy storms I have never lost signal...I do have a good clear shot thru the trees to the satellite so maybe that helps...
At my previous residence I did loose signal with the tv dish during storms, which isn't supposed to be as sensitive as the internet dish...(I did not have a internet dish there, just used 'dialup' lol...this was 7+ yrs ago..)
But now even during the big bad thunderstorms I kept signal for both....maybe the dish design has improved? This is a brand new system... I am not sure....