Tropical Storm Lana strengthens to Category 1 hurricane, eye projected to graze South Florida by Friday

The National Hurricane Center upgraded Tropical Storm Lana to a Category 1 hurricane in its 5 a.m. advisory, citing rapid intensification over record-warm Gulf Stream waters.

Maximum sustained winds are now near 80 mph, with additional strengthening expected in the next 24 hours. The storm is moving west-northwest at 12 mph on a track that brings the eye within 60 miles of Miami-Dade County by late Friday.

Miami-Dade and Broward counties are under a hurricane watch, with tropical storm conditions possible as early as Thursday afternoon. Residents in evacuation zones A and B are urged to begin storm preparations now.

FOX 5 Miami's Weather Authority team will provide continuous coverage through landfall.