If the Weather Forecast Predicts Rain, Is One Still Obligated to Sleep in the Succah?

If the weather forecast predicts rain, is one still obligated to sleep in the succah, or can we say that since he knows it’s going to rain, he is mitzta’er and exempt from sleeping in the succah?

R’ Zilberstein (Chasukei Chemed, Succah 29a) discusses this shailah.

The Ritva (Succah 29a) writes: אם לא היה אוכל עדיין וראה גשמים באין ושמים מתקדרין בעבים אוכל חוץ לסוכה ואין מטריחין אותו לעלות עד שיגמור כל סעודתו - "If one hasn’t started eating, and he sees rain coming and the skies covering over with clouds, one may eat outside the succah, and we don’t bother him to go up to the succah, until he finished his meal".

However, the Ran (13a MiDafay HaRif) writes on the Gemara which says מאימתי מותר לפנות - משתסרח המקפה "When is one allowed to go inside, from when the porridge spoils" that: נראה לי מדנקט כי האי גוונא דוקא כשהתחיל לאכול הוא דאינו מותר לפנות אלא משתסרח המקפה, כדי שלא יראה כמבעט בסוכתו ויוצא אבל לא התחיל ליכנס בה, כל שמצטער מחמת גשמים פטור ..אבל למעשה איני סומך על סברתי שאין בזה ראיה ברורה. - "It seems to me, from the fact that the Mishnah said ‘from when one starts to eat’ that only once one has started to eat must he stay until his food starts to get ruined, to ensure that it doesn’t look like he is upset at his succah and is leaving, if, however, one hasn’t started, if he is uncomfortable due to predicted rain he is exempt … Practically I don’t want to rely on this as it’s not such a clear proof."

Our question would seem to depend on the machlokes Ran and Ritva. According to the Ritva if one sees it is going to rain, he is exempt from succah, and according to the Ran he is obligated. However, it could be, the Ran is only talking about eating, as it’s not so difficult to stop eating and go inside, however, when it comes to sleeping it’s more difficult, and perhaps the Ran agrees that one doesn’t need to even start off in the succah.

On the other hand: Perhaps the Ritva is talking about a case when the skies have already clouded over and it is certain that it will rain, as opposed to our case where experts predict it will rain, where there are stories daily of them being wrong. Therefore, perhaps we can’t rely on them.

The Da’as Torah (639:5) writes: The Ritva is against all the poskim, and the matter needs looking into if a berachah can be said in such a case.

The Shu”t Shevet HaKehosi (Vol. 1, siman 199 and Vol. 3 siman 192) brings from R’ Elyashiv that as long as it hasn’t started to rain, one is obligated to go to sleep in the succah.