The record snowfalls and subsequent runoff in the Pacific Northwest has led to massive electrical output this year, but the effect is wearing off suddenly and quickly.
In June, the surplus generation over 2016 was equivalent to about 1 BCFD of natural gas. But June's average hydro output of 12.8 GW has fallen to 8.6 GW as of yesterday, and should generally decline further throughout the month.
This should reduce exports to California, which would in turn increase thermal generation there. Thermal output in CAISO has been badly lagging prior years up to now:
