Testing Sensitivity of Short-Term Model Forecasts to Aircraft Observations

We investigate the impact of PEMDAS Aircraft Observations on short term model forecasts to provide a timely and relevant depiction of current environmental conditions, using an end-to-end forecast system for use in current operations. A series of flights tests using the airborne meteorological data sensors took place during June, July, and August of 2017 over New York, Texas, and Louisiana, at various times and synoptic conditions. Flight observations were collected, formatted, and integrated into 3-km resolution Weather Research and Forecasting (WRF) ARW model domains running continuously for each of the regions. WRF observational nudging and four-dimensional data assimilation were applied to mach-corrected temperature, as well as dew-point temperature observations taken at 1-second intervals along the flight path, to provide continuously updating, 3-hour forecasts every hour, using a three-hour assimilation cycle. Using the NCAR Model Evaluation Toolkit (MET) evaluation package and NCEP Unified Post processor, initial results are presented to explore the impact of the flight observations relative to cases where no special observations are inserted. Initial results demonstrate an improved representation of circulation features over the field test locations.