Warm air has 'sea fog' invading some NC beaches

The warm up that North Carolina will experience in the coming days is bringing an unusual weather phenomenon to some of its beaches: Sea fog.

The fog is expected to move into the beaches around Wilmington and southeastern North Carolina in the coming days. It creates an unusual, almost eerie effect on the beach where fog will sit along the shoreline.

How does it happen? When warm air moves in, the air can hold lots of moisture. When that air moves over the ocean, condensation can form. That happens due in part to our water temperatures this time of year being in the low 50s.

"You get that warm, moist air moving over that cold ocean water and it cools the air mass sitting over the water," said WRAL meteorologist Elizabeth Gardner. "When you cool it, you have condensation that forms. It's the function of the warm air moving over the cold ocean temperatures that creates the cloud."

Gardner said several factors have to come together for the fog to occur.

"You need a southeasterly flow that's coming onshore, the winds to be sort of light because if the winds are too strong, that kind of mixes the atmosphere too much for fog to form," Gardner said. "It's kind of a fine line of having enough warm air to move over the cold water without it mixing up and causing the fog to dissipate."

Much like it does for drivers on the roads, the fog creates visibility problems for boaters.

"You could be inland and you head out to the beaches and all of a sudden, you're in a cloud," Gardner said. "It's warm and sunny a few miles back and you appear at the beach expecting to have a nice day, and it's cloudy and cool on the beach."

In the Triangle, temperatures are expected to yo-yo between the 70s and the 50s in the coming days. The forecasted high for Wilmington on Wednesday is in the upper 70s.