I was in my work office and went into the office meeting room to drop off some things prior to a scheduled meeting. i was alone in there. the meeting room has a large window looking north across the south saskatchewan river valley. i was looking out the window and when i looked up i noticed a small white circular shape to the northwest that was moving to the east. my initial thought was that it was a small white party balloon being blown in an west to east direction (with the direction of the prevailing winds). the sky behind it was clear blue though there were some clouds in the sky. i could not see any other aircraft in the sky. the balloon seemed to be wobbling slightly and the movement was at a constant rate and velocity. i was wearing my glasses. my initial feeling was that it was probably 250 to 500m high (above ground level). it still seemed kind of odd and i wasn't sure what it was so i walked down the hall and asked one of our clerical staff to come and take a look at something. she came down to the room and i pointed it out and asked her if it was a balloon. she seemed immediately uncomfortable, said yes and quickly left. i continued to watch it for another minute or so. as the orb moved east it approached a large cloud. i fully expected to see the balloon drift in front of the cloud (between the cloud and me) but instead it seemed to disappear behind or into the cloud. now the cloud had the common various shades of white and grey that most clouds have so i may have simply lost it in the background clutter but it sure seemed to actually disappear behind it. i watched for another 4 or 5 minutes but never caught sight of it again. i subsequently went back to my office and went online to check the cloud ceiling and it was roughly 2700m. if the orb did indeed disappear behind or into the cloud it was significantly larger and higher than my initial impression (party balloon size). the sighting lasted no more than 2 or 3 minutes. i never discussed the sighting with the other staff member again. i got the distinct impression she wouldn't want to. my cell phone was at my desk at the opposite end of our office so no images. i sat on this for over a year until i recently retired. one other thing, if the distance to the object was indeed as high or higher than the cloud ceiling then the horizontal distance from my vantage point was also significantly further northwest than i thought, perhaps far enough to be close to or over cfb suffield, a canadian forces base and large tank range near medicine hat. the base is utilized by several nato member countries but mostly the brits.