(Newberg, OR) -- Some vineyards in the Willamette Valley are expected to feel the effects of April's cold weather. Experts say this is the time of year when the first buds start to appear on the vines and that freezing temperatures can kill them. It doesn't mean the vines won't produce, because other buds will form, but the total yield will be down. Low elevation vineyards feel the effects more because higher elevation vines bloom later.