Proto-MSA

*ma-lsay- - rain (Kogan 2015:543)

“One is tempted to connect Proto-MSA *ma-lsay- ‘rain’ with Akk. nalšu ‘dew’ (CAD N1 202, AHw. 724). The unusual sequence of two sonorants in the Akkadian word makes feasible the secondary origin of of n-, whereas the correspondence of Akk. (and PS) š to MSA s has good precedents elsewhere in the MSA vocabulary. This comparison is, however, quite tentative in any case.”

Mehri
məwsē - rain (ML 256)
The main term for the meaning “rain” in MTO and MTjŠ (see Kogan 2015:515-516).
Jibbali
mósέ - rain (JL 165)
Soqotri
mέsɛ - rain (LS 234, CSOL I 604, II 529, Naumkin et al. 2015a:78, Bulakh 2021:280, Bulakh et al. 2021:285–286)