Yes, WESTS is a Scrabble word!

Letter values in Scrabble US: W 4, E 1, S 1, T 1, S 1.

Is it a valid word?

WESTS is a valid word in the official Scrabble dictionary (US), the UK Scrabble Dictionary and Words with Friends (ENABLE).

the countries of (originally) Europe and (now including) North America and South America
the cardinal compass point that is a 270 degrees
the region of the United States lying to the west of the Mississippi River
the direction corresponding to the westward cardinal compass point
British writer (born in Ireland) (1892-1983)
United States film actress (1892-1980)
English painter (born in America) who became the second president of the Royal Academy (1738-1820)
a location in the western part of a country, region, or city

Also: due west, w, western united states, rebecca west, dame rebecca west, cicily isabel fairfield, mae west, benjamin west.