Colour state other than clouds or low visibility (e.g. ice or other obstructions) then the word BLACK is written in full and placed immediately before the actual colour state (e.g. BLACKWHT). The colour state may be appended to a METAR report. A short period forecast called a "TREND" which covers the following two hours from the observation may also be added, often with reference to the colour state. The following criteria are used to determine the colour state: Colour state Colour states is a system used for quickly showing meteorological conditions. Meteorological colour states are determined by the relevant worst condition from
Design–Expert the number of test runs needed. ANOVA is provided to establish statistical significance. Based on the validated predictive models, a numerical optimizer helps the user determine the ideal values for each of the factors in the experiment. Design–Expert provides 11 graphs in addition to text output to analyze the residuals. The software determines the main effects of each factor as well as the interactions between factors by varying the values of all factors in parallel. A response surface model (RSM) can be used to map out a design space using a relatively small number of experiments. RSM provides an estimate