Southwest's rhymes with:
northwest's, bequests, midwest's, natwest's, northwest's, norwest's, quests, requests, west's, arrests, attests, bequests, best's, breasts, chests, crests, digests, divests, fests, guest's, guests, guests', infests, invests, jests, midwest's, molests, natwest's, nests, northwest's, norwest's, pests, quests, reinvests, requests, rests, retests, suggests, test's, tests, tests', vests, west's
Southwest's sounds like:
sadistic, southeast's, stakeouts, statistic, statistics, statistics', statists, stochastic