The National Weather Service in Mount Holly has issued a caution for travelers this morning due to a dense fog advisory in effect until 9 AM EST. According to the NWS report, visibility will be reduced to a quarter mile or less in areas of dense fog across parts of northern Delaware, southern New Jersey, and southeast Pennsylvania. Cities such as Wilmington, Philadelphia, and Atlantic City are among those affected by the impaired visibility. The advisory urges drivers to slow down, use their headlights, and maintain plenty of distance from other vehicles.

As the day progresses, the fog is expected to clear, but overcast skies will remain, with a high near 55 degrees. However, conditions are set to deteriorate sharply by nightfall. Rain is expected to begin steadily falling after 9 PM, with a 100% chance of precipitation. New rainfall amounts will range between a half and three-quarters of an inch. Motorists are urged to be prepared for sudden changes in driving conditions as the rain begins.

The weather will take another turn tomorrow with rain persisting throughout the day, potentially escalating into thunderstorms between 1 PM and 4 PM. The likelihood of precipitation remains high at 100%, and it is possible that some of the storms could produce heavy rainfall. Accumulated new rainfall could reach between 1 and 2 inches. Drivers should be advised that the heavy rain may swiftly impact road conditions, introducing risks of hydroplaning and reduced visibility.

Looking to the latter half of the week, the rain is forecasted to subside before 10 PM tomorrow night. Thursday promises clearer skies with a sunny high of 37, followed by a chilly night with lows hovering around 21 degrees. The wind is expected to remain active, with west gusts as high as 25 mph. Further along in the week, sunshine continues into Friday, while the weekend brings the possibility of more rain and partly sunny conditions to the Philadelphia area.

Residents and travelers in the region should stay informed about the upcoming weather conditions. The latest updates are available on the National Weather Service's official website, providing real-time information and advisories. This morning's dense fog is just a precursor to what appears to be an unsettled and wet week ahead.