The PACific landfalling JETs (PACJET) experiments took place during January - March 2001 and 2002. During this period the GOES rapid scan WINDs EXperiment (GWINDEX) was initiated at the Cooperative Institute for Meteorological Satellite Studies (CIMSS), University of Wisonsin - Madison. GWINDEX provided one (three) hourly high-resolution satellite-derived atmospheric motion vectors (AMVs) over the eastern North Pacific Ocean during PACJET 2001 (2002). This data has the potential to greatly improve analyses and forecasts over the eastern Pacific and western North America when assimilated into numerical weather prediction models.

This presentation will use the MM5 Adjoint Modeling System to: 1) calculate the sensitivity of the forecast error to changes in the initial conditions and 2) to perform a four-dimensional variational data assimilation of the AMVs. Several cases will be considered to determine the changes in forecast errors associated with the assimlation of these AMVs.