Rịba ama amaokwu a dị n'okpuru ma zaa ajụjụ ahụ mgbe e mesịrị n'otu asụsụ ahụ dị ka amaokwu ahụ:  Passage: A lee trough, makwaara dị ka a ike trough, bụ "A mgbali trough kpụrụ na lee n'akụkụ nke a ugwu n'ọnọdụ ebe ifufe na-afụ na a ịrịba akụrụngwa gafee ugwu ridge; mgbe mgbe hụrụ na United States ihu igwe map n'ebe ọwụwa anyanwụ nke Rocky Mountains, na mgbe ụfọdụ n'ebe ọwụwa anyanwụ nke Appalachians, ebe ọ bụ obere kpara". Ọ nwere ike ịkpụzi ya ma ọ bụ n'ihi mkpakọ adiabatic nke ikuku na-adaba n'akụkụ lee nke ugwu, ma ọ bụ site na cyclogenesis nke sitere na "njikọ ihu igwe jikọtara ya na mgbatị kwụ ọtọ nke ogidi ikuku na-agafe n'elu ugwu ahụ ma na-agbadata mkpọda lee".  Ajụjụ: Olee otú a pụrụ isi kpụpụta ebe a na-esi enweta mmiri?
ma ọ bụ n'ihi mkpakọ adiabatic nke ikuku na-emikpu n'akụkụ mmiri nke ugwu, ma ọ bụ site na cyclogenesis nke sitere na "njikọ ihu igwe jikọtara ya na mgbatị kwụ ọtọ nke ogidi ikuku na-agafe n'elu ugwu ahụ ma na-agbadata mkpọda mmiri