Assimilating Kentucky Mesonet observations in a real-time forecasting system at the Kentucky Climate Center

We present the first stage of development of a forecasting system that employs the variational data assimilation of observations from multiple sources, included the near surface observations from the Kentucky Mesonet. The Kentucky Climate Center within the Department of Geography and Geology at Western Kentucky University is home to the expanding Kentucky Mesonet, a dense network of real-time research grade meteorological observations and data collection systems. Currently there are 64 operational stations with plans to expand to over 100 stations.

Version 3.5 of the Weather and Research Forecasting (WRF) modeling system is utilized with and without three-dimensional variational data assimilation (3DVAR). Version 3.5 of the WRF data assimilation system is used in conjunction with NCEP GFS final analysis to provide initial and boundary conditions for WRF forecasts. When 3DVAR is utilized, all simulations include surface and upper-air observational data from the National Center for Atmospheric Research/CISL Research Data Archive. One set of simulations will also include surface observations from the Kentucky Mesonet. Root Mean Square error differences between forecasts with and without observational assimilation are analyzed for the summer and fall of 2013. Preliminary results with a four-dimensional variational data assimilation system will also be presented.