southwesterly vs southwestern

southwesterly and southwestern both are adjectives.

Word	Noun	Adjective	Verb	Adverb
southwesterly	No	Yes	No	No
southwestern	No	Yes	No	No

As adjectives, southwesterly and southwestern are synonyms defined as:

southwesterly and southwestern: situated in or oriented toward the southwest

Other synonyms of southwesterly include southwest.

southwesterly (adjective)	southwestern (adjective)
situated in or oriented toward the southwest	situated in or oriented toward the southwest
coming from the southwest	of a region of the United States generally including New Mexico, Arizona, Texas, California, and sometimes Nevada, Utah, Colorado