AREAS FOG TO DEVELOP OVERNIGHT WHICH MAY BECOME LOCALLY DENSE... Areas fog likely to develop overnight possibly becoming locally dense with visibilities as lows as 1/2 mile. Main areas of concern are Connecticut and western Massachusetts. A Dense Fog Advisory may be needed if widespread dense fog with 1/4 mile visibility develops. Motorists should be prepared for sudden changes in visibility. Use low beam headlights and keep a safe distance between your vehicle and the one ahead of you.