is similar to
presaging ill fortune
"ill omens"; "ill predictions"; "my words with inauspicious thunderings shook heaven"- P.B.Shelley; "a dead and ominous silence prevailed"; "a by-election at a time highly unpropitious for the Government"
is similar to
extremely ominous
"world events of thunderous import"
see also
(of winds or weather) tending to hinder or oppose
"unfavorable winds"
is an attribute of
the favorable quality of strongly indicating a successful result