Consider the following premises. If Charles were a sailor, then it is snowing. If Charles were a sailor, then Karen is not taking a plane. Karen is taking a plane. If it snows, then Charles is a sailor. Can we infer the following from them? It is snowing.
 From the fact that if Charles were a sailor, then it is snowing, and that if it snows, then Charles is a sailor we can infer that Charles is a sailor if and only if it is snowing. From the fact that if Charles were a sailor, then Karen is not taking a plane, and that Karen is taking a plane we can infer that Charles is not a sailor. Finally, from the fact that Charles is a sailor if and only if it is snowing, and that Charles is not a sailor we can infer that it is not snowing, which contradicts that It is snowing. Therefore, the answer is no.