Finding Meaning in Chaos

The use of ensembles is vital in interpreting the influence of chaos in weather prediction. However their use has one major disadvantage; there is a large increase in the volume of data involved in using a probabilistic approach as opposed to purely deterministic forecasting. This can mean that much of the significant information can be lost in a sea of data and the advantages of ensembles can be undermined by time-constraints.

In this paper we will outline the various graphical and statistical methods used within the UK Met. Office to convey the information contained in the ensembles to the forecaster. We shall examine the relative merits and disadvantages of several of the different methods, including:

· Ensemble Means,

· Probability Maps,

· Tubes and Other forms of Clustering,

· Probability Density Functions for individual Stations.

We shall investigate each method to see how well they satisfy the aim of turning the raw data into something that is easy to use, manageable and yet informative.