( Thunderstorms ( ( can ( cause ( ( The Narrows ) ( to ( ( flash flood ) ( during ( the summer ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NNS Thunderstorms)) (VP (MD can) (VP (VB cause) (S (NP (DT The) (NNPS Narrows)) (VP (TO to) (VP (VB flash) (NP (NN flood)) (PP (IN during) (NP (DT the) (NN summer)))))))) (. .)))
Thunderstorms can cause The Narrows to flash flood during the summer.
(ROOT (S (NP (DT A) (NN stream) (NN flooding)) (VP (VBZ is) (ADVP (RBS most) (RB likely)) (VP (VBN caused) (PP (IN by) (NP (DT a) (NN thunderstorm))))) (. .)))