People have lots of these and they do not come to pass or are contradictory, you have 3 choices- some are from the enemy, some are from our own wishful desires and come out in dreams.

 And some are from God- which dealt with disasters that did not come to pass and were crossed out by repentance or / and prayer.  Just as Jonah was a real prophet with a message of destruction, but his message brought repentance and thus no fulfillment.
 
I personally pray against the predictions of huge disasters that people see coming, negating  or postponing them.  I do not know the source of the predictions, but I know with God- all things are possible and His desire is that all come to repentance and faith.
 
There is also a big shelf in my mind to place “Prophecies” on.

  I have been burned real good by listening to a  preacher that I thought was a prophet a long time ago.
 
  Also ask – what is the track record of this person decreeing this thing?  What kind of spirit is the person projecting?  Are they angry with almost everyone?  Are they bringing a bunch of the old Law into their decrees?  Maybe some of what they are saying actually does come from on High, but gets mixed with their own emotions.

We do know the prophet Joel predicted a big increase in dreams and visions, so we are sure seeing that.  What we don’t know for sure is the source of all of them.  There are 2 prophetic people I have no doubt about.  One is David Owuor-  and I have prayed to negate a couple of the disasters he has seen.