There's an article in Decanter which says that St Michelle - one of the USA's biggest producers - is going to purchase 40% less fruit over the next 5 years! That's an awful lot of grapes!!
It appears with the limited information available that they just can't grow the volume end of the business profitably so are adjusting their model to produce less but better wines!
'Compared to places like the Central Valley of California or lower elevations in Argentina, they can't just can’t get the high yields to compete at those price points so the opportunity for Washington growers and winemakers is to make more site-specific wines that show the personality of a vineyard or region. Although the transition may be painful, the wines will be more interesting going forward.’
One winemaker is quoted saying 'these troubles are indicative of larger trends – older wine drinkers are enjoying the cellars they’ve built over decades, and younger consumers are drinking less in general and more intentionally'
Interestingly, in the case of Washington, it is generally agreed that it is much more suitable for quality production than quantity anyway.
So here's to better Washington wines (but less of them!).