score:5
The belief of Jehovah's Witnesses and other religions regarding a water canopy that existed at the time of earth's creation is not a concept that is a result of doctrine but one that is advanced in the Bible itself. Genesis 1:7 says: "So God made the expanse and separated the water under the expanse from the water above it. And it was so." The Jewish Tanach agrees with this same concept saying, "And God said: 'Let there be a firmament in the midst of the waters, and let it divide the waters from the waters.' And God made the firmament, and divided the waters which were under the firmament from the waters which were above the firmament; and it was so."
Jehovah's Witnesses recently published a series of articles on creation which affirms the belief in a canopy of vapor that existed in the pre-flood era (see Awake! March 2014). Additionally an article from the January 1, 2004 Watchtower magazine says this: "Where did the water causing the global Flood come from? During the second creative period, or “day,” when the earth’s atmospheric “expanse” was formed, there were waters “beneath the expanse” and waters “above the expanse.” (Genesis 1:6, 7) The waters “beneath” were those already on earth. The waters “above” were huge quantities of moisture suspended high above the earth, forming a “vast watery deep.” These waters fell upon the earth in Noah’s day."
In regards to whether that canopy will ever exist again has not been officially discussed in recent Jehovah's Witnesses literature.