The new system uses a mySQL database that is populated by mesonet wind observations from which relevant statistics are calculated. Observation sites over a specific region (Florida) and time period (1 August 2008 31 July 2009) are examined. QC checks are run within the database by using simple SQL queries and a flagging system. Initial QC checks are primarily based on comparing mesonet site observations with known high-quality observations (i.e. METAR sites) and the first guess field.
The primary goals of this study are twofold: to create an expanded static list of mesonet sites to be used in the RTMA, and to create a dynamic list that changes based on observed wind direction. Observed wind speed biases (with respect to the background field) in 8 directional bins are compared with those of nearby METAR sites. Sites with similar bias to that of nearby METAR sites are identified as acceptable. This dynamic list represents a new tool that can be used to increase the number of quality observations in the RTMA.
The benefits of using a database approach for quality control purposes are demonstrated. The system can be applied in a computationally inexpensive and fairly straightforward manner. The database system allows for multiple QC/QA checks to be performed in quick succession, and could easily be adapted for use in other assimilation systems and thus could easily be adapted to run in real time.