This is the weather pattern that has persisted across North America for much of the last year. The purple area is high pressure in the upper atmosphere that has taken up residence over the western U.S. or eastern Pacific with few exceptions during this time.
As long as that high is in that position, West and Central U.S. will be drier than normal.
The computer models are tentatively starting to show a change in pattern in about ten days to two weeks.
Forecasts that far out are tricky. For moisture-starved areas, let us hope it is correct.