Traditionally the analysis work in the National Meteorological Centre (NMC) of the UK Met. Office (UKMO) has been by hand, using a paper-based approach. Over the last couple of years development work has investigated the use of mathematical techniques and graphical software to provide the alternative facilities on a UNIX workstation system (Horace). These facilities can then lead to full or partial automation of the analysis process, but this transition has not been without its problems and concerns.
Fundamental to any analysis scheme is the underlying observational data. Whilst we rely on its integrity to provide us with an indication of the state of the atmosphere, errors in its accuracy can have a significant impact on any automatic technique. It is this quality control assessment that becomes critical with on-screen analysis practises with the judgement of the forecaster a key part. Consequently tools have been provided to enable them to review and correct the data at all stages before accepting the final product.
As with most graphical presentations a lot of the value of the final visualisation is realised by using the most appropriate style. Once the base data has been quality controlled therefore graphical software can be used to provide the forecaster with the control over presentation styles. The traditional contoured field can now be supplimented with other forms such as streamlines or direction arrows as well as the use of colour.
This paper will present an overview of the role of analysis in the forecast process, before describing some of the limitations of the hand analysis process and how they can be alleviated with on-screen techniques. It will further explain those techniques and how they have been developed to solve new problems that only appear once you begin to consider analysing data on-screen. Brief mention of the tools now available to the forecaster will be made, culminating in a walkthrough of the end-to-end production process.