Graphic reads: Dense Fog Advisory Expanded to Southshore and now includes St. Charles and St. John Parishes, Be prepared for sudden drops in visibility along area roadways in the advisory area, What To Expect: Areas of fog will result result in visibility 1/4 mile or lower in some areas, When: Now through 10 AM Saturday morning, Safety: Be prepared for sudden changes in visibility Slow down & increase following distance. Use low-beam headlights.