( ( In ( addition ( to ( jet-stream formations ) ) ) ) ( , ( cirrus ( often ( ( germinate ( when ( ( strong winds ) ( are ( forced ( to ( ascend ( as ( they ( cross ( over ( mountain ranges ) ) ) ) ) ) ) ) ) ) ) ) . ) ) ) ) )
(ROOT (S (PP (IN In) (NP (NP (NN addition)) (PP (TO to) (NP (JJ jet-stream) (NNS formations))))) (, ,) (NP (NNS cirrus)) (ADVP (RB often)) (VP (VBP germinate) (SBAR (WHADVP (WRB when)) (S (NP (JJ strong) (NNS winds)) (VP (VBP are) (VP (VBN forced) (S (VP (TO to) (VP (VB ascend) (SBAR (IN as) (S (NP (PRP they)) (VP (VBP cross) (PP (IN over) (NP (NN mountain) (NNS ranges)))))))))))))) (. .)))
In addition to jet-stream formations, cirrus often germinate when strong winds are forced to ascend as they cross over mountain ranges.
(ROOT (S (NP (NNS Streams)) (ADVP (RB often)) (VP (VBP start) (PP (IN in) (NP (NNS mountains)))) (. .)))