( ( Precipitation ( in winter ) ) ( usually ( ( accompanies ( ( the passing ) ( of ( a ( cold front ) ) ) ) ) . ) ) )
(ROOT (S (NP (NP (NNP Precipitation)) (PP (IN in) (NP (NN winter)))) (ADVP (RB usually)) (VP (VBZ accompanies) (NP (NP (DT the) (NN passing)) (PP (IN of) (NP (DT a) (JJ cold) (NN front))))) (. .)))
Precipitation in winter usually accompanies the passing of a cold front.
(ROOT (NP (NP (NP (NNP Precipitation)) (ADJP (RB commonly) (JJ occur))) (PRN (-LRB- -LRB-) (PRP s) (-RRB- -RRB-)) (PP (IN along) (NP (DT a) (JJ cold) (NN front))) (. .)))
Precipitation commonly occur(s) along a cold front.