We've praised Weather HD many times here at TUAW, and now the folks at Vimov have outdone themselves with Weather HD 2 (US$0.99), making a gorgeous app even prettier.
Weather animations have been completely redone, with 3D maps you'll be proud to have just sitting on the screen when your iPad or iPhone isn't doing anything else. You can see the weather in multiple locations at once, and get push alerts (USA & Europe) for severe weather. The weather data comes from Weather Underground.
Weather HD 2 adds some social features so you can share your weather with friends or see what's happening in their cities.