in Obama's speech...Yet, every so often the oath is taken amidst gathering clouds and raging storms...Is this an example of imagery...i feel this is appealing to sight...in analysing...the oath is taken place among a crisis in america...economical crisis and well as war

Answer 1

Yes, you're right. Those are metaphors: "gathering clouds" and "raging storms."

Answer 2

... and yes, metaphors are one type of literary device that produce imagery.