Q. I have, as everyone else already said Mashiv Haruach more than thirty days, but I still find myself when I lose concentration saying Morid Hatal (I davn sefard), If I can’t remember what I said, do I have to repeat shmoneiesreh?

A. Horav Shlomo Miller Shlit”a pointed out that you don’t have to repeat the Amida for two reasons. Firstly Shulchan Aruch (O.H. 114: 5) rules that during the rain season if one forgot to recite Morid Hageshem but said Morid Hatal as he is used to, he complies after the fact and does not have to repeat the Amida. Secondly, the thirty-day chazaka period mentioned by the Remoh (ibid. 8) is effective also in removing the prior existing chazaka of not saying Morid Hatal and creates at least a balanced doubt that Mashiv Haruach was said. That suffices to comply after the fact.

Rabbi A. Bartfeld as revised by Horav Shlomo Miller Shlit”a