Special Weather Statement issued February 16 at 10:39AM PST by NWS Pendleton OR

Patchy dense fog is blanketing portions of the Blue Mountain
foothills with visibility of one-quarter mile or less reported in
some places, including along I-84 and OR-11. Be prepared for
sudden changes in visibility, slow down, and use low-beam
headlights if encountering dense fog. Temperatures are below
freezing in many locations so roadways may be slick.