Fluxes across the west coast resolved by Picket Fence observations during STORMFEST

Meteorological features that force mesoscale weather systems that develop in the central U.S. often form far upstream over the data-sparse Pacific Ocean. It is hypothesized that the temporal and spatial resolution of the current rawinsonde network along the west coast may not he sufficient to detect and measure flow features moving inland. During the STORMFEST experiment in February-March 1992, a Picket Fence' of seven rawinsonde stations were interspersed among the seven regular rawinsonde sites from Port Hardy, British Columbia to San Diego, CA. All sites obtained observations every 3 hours rather than the normal 12 hours. The objective was to examine the feasibility of utilizing extra observations in time and space to improve upstream boundary conditions for forecasts of mesoscale weather events in the central U.S. Fluxes of mass, heat, momentum, moisture, kinetic energy, and potential energy across the west coast resolved with various spatial and temporal combinations of Picket Fence data were compared with the 12-h regular site sondes as the standard. In the best case in which a wave system creased the middle of the Picket Fence, significantly different fluxes were calculated with the full spatial and 3 h Picket Fence observations. For other systems that crossed near the ends of the axis, only small changes were detected by the additional observations.