Impact of Network Wind Profiler Data on a 3-h Data Assimilation System

Abstract

This paper examines the influence of data from the NOAA Wind Profiler Demonstration Network on a mesoscale data assimilation system. The Mesoscale Analysis and Prediction System is a 3-h intermittent data assimilation system configured in an isentropic-sigma framework. To measure the impact from profiler data on 3-h forecasts valid at 0000 and 1200 UTC, parallel runs with and without profiler data were verified against rawinsonde data. A sample case study is also presented to show the magnitude of the modifications at verification sites. In evaluations from case studies and statistics gathered over longer test periods, the profiler data improved the overall short-range forecasts in the study area. This improvement was most evident at 300 hPa where the root-mean-squared wind errors (averaged over the verification area) were reduced by 0.7 m s?1, and corresponding height errors were reduced by 2 m. The 300-hPa improvement in short-range forecasts from the case study at individual rawinsonde stations was as large as 10 m s?1 for winds and 40 m for heights.