The National Weather Service issued a report at 2:17 a.m. on Thursday for patchy fog until 9 a.m. for Western Chester, Eastern Chester, Western Montgomery, Eastern Montgomery, Upper Bucks and Lower Bucks as well as Berks, Lehigh, Northampton, Delaware and Philadelphia counties.

"Patchy fog has developed this morning across the area. While the fog is not expected to be widespread, it could become locally dense with visibilities under one quarter mile. Use caution when traveling and be prepared for changes in visibility," describes the weather service.

Fog safety: Tips from the weather service for safe travels

If you must venture out in foggy conditions, keep these safety tips from the weather service in mind:

Reduce speed:

Slow down and allocate extra travel time to reach your destinat

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