Old blog post, but interesting nonetheless.
The definition of miracle seems rather fuzzy, imho.
On the one end, people say splitting a sea in two is a miracle. On the other, gravity and tides are known natural phenomena and it is theoretically possible to split a sea in two, given that a bunch of highly unlikely events happen simultaneously and someone is paying attention.
Often, an event is called a miracle because it's very personal, e.g. a loved one surviving cancer or a gruesome accident. I'd say the explanation for these cases just happen to be beyond comprehension, but not they're certainly not necessarily beyond the forces of nature.
There are those who say that miracles are things that can never happen because there are very specific scenario constraints, e.g. walking off the top of a building and expecting not to turn into a flattened pancake. But hey, it can be done. Voluntarily, at that.
I tend to be pragmatic and go more by the street usage of the term miracle (i.e. that it can happen), so I figure that since miracles only escape our understanding but not necessarily laws of nature, yes, we can be rational and believe in miracles.
As the saying goes, I only know that I know nothing.