During the spring of 2004, several sonic anemometers were placed at a busy intersection in the Westminster district of central London, UK, as part of the Dispersion of Air Pollution and its Penetration into the Local Environment (DAPPLE) project. This multi-year experiment was coordinated by meteorologists at several British universities to study the effect of urban environments on wind patterns. Sonic instruments measured individual wind components and sonic temperature at high frequency for several weeks. A reference anemometer was placed on top of a nearby building. Additionally, an anemometer was placed on the British Telecom Tower in London, UK, well above the urban canopy layer. The geometry of the buildings bordering the intersection was complex. To facilitate with the data processing, a natural coordinate system was defined with Marylebone St. East being the 0° angle. The first quadrant featured a wide open space, while the other quadrants contained buildings with heights between 10 and 34 meters. The data from this experiment were analyzed in two different ways. The first part determined the variability in wind direction for all anemometer locations under certain control regimes. Predominantly, channeling and recirculation helix patterns were observed. It was found that the ratio of the widths between two intersecting street canyons has a great effect on the wind flow around the intersection. The second part of the analysis focused on the intersection anemometers and the wind direction's effect on vertical velocity and convergence. Increased horizontal wind speeds lead to less wind direction variability and reduced vertical motion in the great majority of cases. With increasing measurement height, vertical motions became more significant. However, a clear link between vertical motion and horizontal position around the intersection could not be established.