The Philadelphia office of the National Weather Service issued an alert Thursday morning regarding the formation of so-called “black ice early this morning from Eastern Pennsylvania through much of the northwest two-thirds of New Jersey onto parts of the Delmarva.”
Black ice, or “clear ice,” refers to a thin coating of glazed ice on a surface. While not truly black, it is virtually transparent, allowing black roadways or the surface below to be seen through it. The usually low levels of noticeable ice pellets, snow, or sleet surrounding black ice makes those areas virtually invisible to drivers or persons stepping on it. Thus the enhanced risk of skidding and accident due to the loss of traction.
The NWA went on to say Thursday, “Temperatures plunging well below freezing early today combined with leftover moisture from yesterdays storm is resulting in patches of black ice.
“Be alert stepping out of doors this morning, as well as traveling on your driveway and on some roads that still have a slight film of slush in places. Ice may be present and difficult to see.
“And where ice covered trees in Eastern Pennsylvania and the Northwest half of New Jersey yesterday, gusty winds might knock down a couple of still ice-laden limbs.”