Final Storm by Deborah Abela

Isabella and her friends have settled into life in New City, attending school and making new friends--including the charming, talented, and eminently humble Aleksander Larson. Isabella quickly finds herself leaning on Aleksander's friendship, a move that distances her friends, particularly Xavier. Meanwhile, the world's weather patterns are becoming increasingly erratic, and the Bureau of Weather and Climate has been failing to predict severe weather events--a failure that endangers the lives of those in New City and plunges the city into rumor and doubt. As a massive storm of ice and snow sets in, it seems the New City can no longer be the safe home its inhabitants need. As friendships, politics, and the weather become increasingly unstable, Isabella, Griffin, Xavier, and their friends must decide where their loyalties lie, face that which seems too good to be true, and once again save this new city they've decided to call their home.