( ( ( East ( of ( ( ( the ( coastal ( mountain ranges ) ) ) , ) ( the ( dominant ( Continental ( Tropical ( ( -LRB- ( CT -RRB- ) ) ( air mass ) ) ) ) ) ) ) ) ) ( ( is also ) ( capped ( by ( this ( subsidence inversion ) ) ) ) ) ) ( , ( commonly ( ( ( ( ( ( referred to ) ( as ( the ( Southwest ( United ( States Superior ) ) ) ) ) ) ( ( Air Mass ) ( -LRB- ( S -RRB- ) ) ) ) , ) ( resulting ( in ( ( the area ) ( known ( as ( the ( desert Southwest ) ) ) ) ) ) ) ) . ) ) ) )
(ROOT (SINV (S (NP (NP (NNP East)) (PP (IN of) (NP (NP (DT the) (JJ coastal) (NN mountain) (NNS ranges)) (, ,) (NP (DT the) (JJ dominant) (NNP Continental) (NNP Tropical) (PRN (-LRB- -LRB-) (NP (NNP CT)) (-RRB- -RRB-)) (NN air) (NN mass))))) (VP (VBZ is) (ADVP (RB also)) (ADJP (VBN capped) (PP (IN by) (NP (DT this) (NN subsidence) (NN inversion)))))) (, ,) (ADVP (RB commonly)) (VP (VBD referred) (S (VP (TO to))) (PP (IN as) (NP (DT the) (NNP Southwest) (NNP United) (NNPS States) (NNP Superior)))) (NP (NP (NNP Air) (NNP Mass)) (PRN (-LRB- -LRB-) (NP (NNP S)) (-RRB- -RRB-))) (, ,) (S (VP (VBG resulting) (PP (IN in) (NP (NP (DT the) (NN area)) (VP (VBN known) (PP (IN as) (NP (DT the) (NN desert) (NN Southwest)))))))) (. .)))
East of the coastal mountain ranges, the dominant Continental Tropical (CT) air mass is also capped by this subsidence inversion, commonly referred to as the Southwest United States Superior Air Mass (S), resulting in the area known as the desert Southwest.
(ROOT (S (NP (NP (DT The) (JJS best) (NN explanation)) (PP (IN for) (SBAR (WHADVP (WRB how)) (S (NP (NN air) (NNS masses)) (VP (VBP move) (PP (IN across) (NP (DT the) (VBN united) (NNS states)))))))) (VP (VBZ is) (SBAR (IN that) (S (NP (DT the) (VBG prevailing) (NNS westerlies)) (VP (VP (VBP move) (NP (NN air) (NNS masses)) (PP (IN from) (NP (NN west))) (PP (TO to) (ADJP (JJ east))) (PP (IN across) (NP (DT the) (VBN united) (NNS states)))) (CC but) (VP (MD may) (VP (VB be) (VP (VBN deflected) (PP (IN by) (NP (DT the) (NN jet) (NN stream)))))))))) (. .)))