Storm Rising (Book Two of the Mage Storms)

In Storm Rising, mysterious mage-storms are wreaking havoc on Valdemar, Karse, and all the kingdoms of the West, plaguing these lands not only with disastrous earthquakes, monsoons, and ice storms, but also with venomous magical constructs - terrifying creatures out of nightmare.
Both Valdemar's Heralds and Karse's Sunpriests struggle to marshal their combined magical resources to protect their realms from these devastating, spell-fueled onslaughts. But as the situation becomes bleaker and bleaker, the still fragile alliance between these long-hostile lands begins to fray. And unless Valdemar and Karse can locate and destroy the creator of the storms, they may see their entire world demolished in a final magical holocaust.