This is definitely not how you'd visualized your Xen'drik expedition.
You'd finally scraped together enough money to embark to Stormreach on a fishy merchant vessel, and now this. Sure, the Korranberg Chronicle and even the Sharn Inquisitive had reported on the rather harsh weather around stormreach lately. Earth tremors and thunderstorms had become too frequent to be normal in the last few weeks in coastal regions all around Eberron, and during your arrival the vessel had come decidedly too close to sinking for comfort. Now, the day after your arrival, you find yourselves staring down a giant wave. After helping carry a few last-second (literally) sacks filled with sand to the already existing barriers (It only made sense to plan in advance, as a local told you yesterday), you crouch down behind the meager fortifications and await the tsunami's impact.
No, definitely not how you'd visualized it.
Severe weather conditions have been wracking the coastlines of Khorvaire and Xen'drik for some weeks now, especially around Stormreach and the Lhazaar Principalities. Riedran ambassadors remain silent and nobody knows what happens in Argonessen, but it seems reasonable to assume that Sarlona and the continent of the dragons are suffering the same.
The campaign begins seconds before the most grave event yet, a tsunami, hits Stormreach - and the PCs are caught right at the front. After distinguishing themselves by helping the city survive the immediate aftermath (optional), they can do what they originally planned: Explore Xen'drik. During this expedition, they can roleplay in between themselves, explore the vast and diverse Continent of Secrets, kill monsters indiscriminately and take their stuff (fun times), and experience some ominous foreshadowing. From these not-so-humble beginnings to (hopefully) save-the-world-and-get-the-girl* level 20 kickassery, they'll learn that the wild weather conditions pose a very real threat and they need to stop them and their origin.
*Girls not included.