LOL, I would not be calling for 2-4" near Harrisburg so quite surprising.  They even double down in their new AFD talking about 1-3 daytime tomorrow. 
 
Farther south, expecting rain to mix with snow for a few hours
Friday afternoon and evening, especially along and south of the
PA Turnpike. High temperatures pushing into the upper 30s to
near 40 should also lead to a bit more melting at the onset and
therefore slightly lower amounts - generally 1-3" with higher
amounts on ridgetops.