I don't think you can ever truly connect climate change to a single weather event, however, what you can do is make connections of climate change to the atmospheric pattern configuration...or something along those lines. For example, if the PJ averaged more north this winter and that has been a theme more often than that over the past several years compared to the longer-term mean you can make an argument (based on ideas of how a warmer climate would argue for this) that is a relation to climate change along with other factors which may have helped (ENSO, QBO, etc).