If indeed related to Akk. nablu ‘flame’, must be also connected with Gez. nabal ‘flame’ (CDG 383), so the Ugaritic-Akkadian isogloss is not exclusive. The unexpected glottal stop in Ugaritic remains, as before, enigmatic (Kogan 2015: 357).
this attestation of *nwm doubtful. Gordon 422 and Del Olmo, Mitos 588 regard the word as a compositum consisting of nhm ‘sleep’ (with an inserted -h-) and mt ‘death’ (otherwise in [WUS 90]).