Storm Surge Effect (public domain image via Wikimedia Commons)
What is storm surge?
When a tropical weather system heads for shore, it pushes seawater ahead of it. The bigger and stronger the storm while it is over the sea, the more water it is capable of pushing. That water comes onto land as storm surge. If you live along the coast, you are vunerable to storm surge. Even if you don't, you still may be.
Storm Surge and Storm Tide
To understand the definitions of these two terms, you need to start at Mean Sea Level, which is the half way point between high and low tide for a particular location.
Storm Surge height (or deepness of the water) is measured from mean sea level. If the event occurs at high or low tide, it will be more or less deep by the amount that the high or low tide varies from mean sea level. In the illustration above, the surge is 15 feet.
Storm Tide takes into account both the normal (low or high) tide, and the surge tide. In the above illustration, if it comes in at high tide (which is two feet above mean) it will be a 17 storm tide. At low tide, it would be only 13 feet.
Since the water coming in is not calm and smooth, waves on top of its surface can add even more height that the water can actually reach.