On the contrary. I think the rabbi has a duty to actively make sure his congregants know to stay home. While most will have the common sense to stay home, there will usually be a small number who, out of foolhardiness, genuine righteousness or some combination of the two, will think that they should risk it. It’s the rabbi’s responsibility to actively announce (or get the word out via telephone, email, text message or however) that the shul will be closed during a weather emergency. The rabbi most certainly should not do nothing.
The Wolf