The National Weather Service issued a report at 3:51 a.m. on Friday for dense fog until 9 a.m. for Northern Warren and Southeast Warren as well as Herkimer, Hamilton, Fulton, Montgomery, Saratoga, Washington, Schoharie, Schenectady, Albany, Rensselaer, Greene, Columbia, Ulster and Dutchess counties. "Patchy dense fog has developed across the area, especially along the Hudson River Valley and in many narrow or sheltered higher terrain valleys. The fog will reduce visibility to a half mile or less, so drivers are urged to use caution this morning and be prepared for rapidly changing visibility. The fog is expected to dissipate by around 9 a.m.," according to the weather service. ...read more read less