( ( ( The ( severe thunderstorms ) ) ( across ( ( north ( central ( and ( central Mississippi ) ) ) ) ( trained ( across ( ( ( ( ( the region ) , ) ( causing ( flash flooding ) ) ) and ) small ) ) ) ) ) ) ( ( ( ( creeks and ) streams ) ( to overflow ) ) . ) )
(ROOT (S (NP (NP (DT The) (JJ severe) (NNS thunderstorms)) (PP (IN across) (NP (NP (NN north) (JJ central) (CC and) (JJ central) (NN Mississippi)) (VP (VBN trained) (PP (IN across) (NP (NP (DT the) (NN region)) (, ,) (NP (VBG causing) (NN flash) (NN flooding)) (CC and) (NP (JJ small)))))))) (VP (VBZ creeks) (CC and) (VBZ streams) (PP (TO to) (NP (NN overflow)))) (. .)))
The severe thunderstorms across north central and central Mississippi trained across the region, causing flash flooding and small creeks and streams to overflow.
(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))))) (. .)))