11.   Patchy fog will again form early this morning, especially in the interior valleys.

12.   The fog formed when warm, moist air from the south was blown or over cool offshore waters.

13.   This fog forms when warm air passes over cold waters.

14.   When the saturated air touches the chilled land, radiation fog forms.

15.   With light winds and abundant, low-level moisture, fog formed.

16.   Dense fog will form at night in the interior of Puerto Rico reducing visibilities to near zero in the predawn hours.

17.   Elsewhere, fog formed in some western parts of Washington, and showers were expected to move into the region from the Pacific.

18.   The clearing skies and damp ground allowed dense fog to form over much of Puerto Rico overnight.