John Hancock Weather Alterations

The John Hancock building makes its own weather.  Dr Desert Flower and I stayed at the Holiday Inn on the Chicago River back in September for my little brother's wedding.  Our room had a spectacular eastern facing view of the John Hancock building and other lake-front-adjacent sky scrapers.  We noticed that as he sun was setting on a Thursday night, that the John Hancock building created its own weather as the dew point dropped and cool moisture laden air coursed over the HVAC units on the top of the building.  There'd be very little clouds (or very thin clouds) until they reached the Hancock, and then they'd grow large enough and thick enough to obscure the top of the building.

Really weird.