Mechanisms of wind channeling in the Hudson Valley, NY.

This study presents the preliminary results from the Hudson Valley Ambient Meteorology Study (HVAMS). The study region, the mid Hudson Valley, is located from –74.1 to –73.6W and 41.6 to 42.8 N. Valley walls range mostly from 200-300m. During September to October 2004 a network of 9 micrometeorological flux stations and 5 meteorological stations were assembled in this valley. Also, vertical profiles from several platforms are available for this period. The above predominant climatological winds are westerly, but in the Valley most of the surface winds are from along valley direction (North/South) direction indicating a channeling are controlled by the pressure gradient. We present several case studies of convective boundary layer development, with the aim to detect the controlling pressure gradients (along- and cross-valley) in data from aircraft, sounders, and from a network of surface weather stations. We also will present the representativeness of each station in the surface network.