1.   A heavy fog that sometimes blankets the road on fall and winter mornings compounds the danger.

2.   All inward bound flights are being cancelled due to heavy fog.

3.   And once, she was forced to stop because of heavy fog.

4.   Like winter almost, except for the heavy fog.

5.   The two lorries collided in heavy fog.

6.   There is heavy fog on all roads tonight so drivers are advised to reduce speed and drive with extra care.

7.   A heavy fog suddenly descended on us, and we realized that we were lost.

8.   Heavy fog made it difficult to see the road.

9.   In heavy fog she collided with a lorry.