Pennsylvania statute and case law doesn't give a clear definition of what "open" and "concealed" mean. Hawkins v Commonwealth provides that carrying a handgun in one's waistband in considered OC, but that's about it.
My unprofessional, uncited opinion is that if you put a jacket over your holster and weapon, that's definately concealed. Though as you presumably have a LTCF, that shouldn't be much of a problem.
To stay in the clear in the winter as far as OCing without a LTCF, I'd say one would need to carry in the style typical of law enforcement, with a jacket that only goes as low as the waist, and an OWB holster keeping the weapon outside of the jacket.
Welcome to OCDO, though. It's a shame that you feel you cannot OC where you live... I don't mean an offense, but have you considered that perhaps you may be overestimating the gun sensitivity of local LEOs? Granted, it's a valid concern, and there certainly have been bad OC encounters with LEOs in the state, but it seems as though LE is usually not oppressive in this state regarding OC. Have you sent the OC training memo to local police stations? It can be found at http://opencarry.mywowbb.com/view_to...mp;forum_id=46 Perhaps sending out a few of those might be the first steps in making OC more comfortable for you and others in your area.