Sure, why not? If there is more power flow into the grid than it can handle something has to give. There are legal mandates to run the hydro, only economic reasons to run the wind. Wind gets dumped. If this happens it will be associated with something that doesn't occur much, a negative electric wholesale market. During the spring, particularly at night, the Mid-Columbia spot price for power will go negative. Produces charged for their output and consumers on the spot market being paid to consume power. In a few weeks that all changes until the next spring.
On a not too terribly unrelated note, the local garbage to energy plants are equipped with a rather large jet condenser for use when their sole steam turbine is down, and they have to keep burning garbage, because it just keeps on coming...
