Heavy fog alert issued for tonight

HARLINGEN — Locally heavy fog is forecast tonight for the Rio Grande Valley, and could reduce visibility in some areas to under a mile.

National Weather Service forecasters say conditions are primed for heavy but patchy fog, and warn motorists the thickest areas will be unpredictable.

The advisory covers coastal Cameron and Willacy counties, Hidalgo County and the ranchlands.

Areas of dense fog are possible again late Tuesday night across South Texas.