PITTSBURGH (KDKA) — The National Weather Service Pittsburgh has issued a Dense Fog Advisory for parts of Western Pennsylvania.

The warning is in place until 10 a.m. on Wednesday.

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Officials say the fog will continue to impact travel across the region. There will be low visibility.

Fog with visibility of 1/4 of a mile or less is expected for several hours.

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The advisory is impacting parts of Allegheny, Beaver Butler, Lawrence, Mercer and Washington counties.

At least 20 arriving flights and seven flights from Pittsburgh Internation Airport were canceled because of the fog.

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