I'm not so sure they will be out yet. This weekend's air temperatures in Ellensburg are forecast to be cold. Water temps are likely to stay in the low 40s to high 30s, which is cold for skwalas to emerge. Sunday afternoon might perk things up if it really gets up to 50 degrees as predicted, but if it were me, I'd take a day off work and go midweek.
It was 29 degrees here this morning when her Ladyship left for work, clear cold & a slight north breeze. I've got an archery club shoot this weekend anyway, and since I'm the VP, I can't weasel out of it