The National Weather Service out
of Mount Holly, N.J. has issued a winter storm warning for much of the area,
including eastern Montgomery, Philadelphia and Bucks counties. The warning,
which was issued at about 9:45 p.m. Monday, will be in effect today from 10
a.m. through tomorrow at 6 a.m.
What can we expect? According to the warning, the “fast moving but potent weather system” could drop six to 10 inches of snow in the area late Tuesday morning into Tuesday night; the heaviest snowfall is expected Tuesday afternoon and Tuesday night, with rates of about an inch per hour.
Temperatures will be in the 20s on Tuesday and wind chills will be bitter as well — starting at about 10 degrees, then dropping to about 10 below zero on Tuesday night.What is a "warning?" According to the National Weather Service website, "a warning is issued when a hazardous weather or hydrologic event is occurring, is imminent, or has a very high probability of occurring. A warning is used for conditions posing a threat to life or property."
This differs from a "watch," which is used when the risk of an event is increased significantly, but its occurrence, location, and/or timing is still uncertain.
Montgomery County has issued a "Code Blue" declaration, which runs through Tuesday. A "Code Blue" is issued in Montgomery County when winter conditions pose a threat of serious harm or death to people without shelter; it is called when the combination of air temperature and wind chill is anticipated to be 20 degrees or less.