Areas of fog, some locally dense, have developed early this morning the Willamette Valley, Upper Hood River Valley, and southwest Washington lowlands, resulting in roadway visibility of one mile or less. Morning commuters should expected to encounter areas of rapidly changing visibility. Freezing fog is also possible this morning where temperatures have fallen below freezing. If driving, slow down, use your headlights, and leave plenty of distance ahead of you. If walking or cycling, wear bright or reflective clothing and carry a light to increase your visibility to drivers.