Patchy fog has developed across portions of north central Oklahoma this evening. Visibilities in some areas will drop to less than a mile at times. If traveling this evening in these areas be prepared for quick changes in visibility over short distances, slow down and use low-beam headlights. The visibility is expected to improve some overnight as winds begin to increase out of the south. Elsewhere some patchy light fog has developed across portions of central and western Oklahoma, but visibilities are expected to remain above 3 miles through the remainder of the evening hours.