Here is a low res photo of the Shanghai World Financial Center (SWFC) taken on the 29th of July about one hour after a good afternoon thunderstorm. Note that the top of the building is generating localized weather in the form of a trailing cloud. This photo was taken from the Executive Lounge on the 38th floor of the Hilton Hotel located in the Jingan Temple area. The winds on this day were coming from the south. As the winds encountered the top of the building, the air foil effect of the opening at the top of the building causes the air to accelerate due to increased path length as the winds wrap around the large opening at the top of the building. This increase in wind velocity then generates a venturi that trails to the north. The venturi then creates a long localized area of lower air pressure. This reduction in air pressure, relative to the surrounding area then allows for the formation of localized clouds to develop along the path of the venturi induced atmospheric disruption.