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impact on the total radar-estimated water volume over the FTG radar umbrella had thes~: other methods been used to form the gauge-radar pairs. In order to determine the impact on the computed bias estimates of using the center radar bin collocated with the gauge instead of the current logic in forming gauge-radar pairs, the software module within the Adjustment algorithm where the pairs are formed was altered, A change was made to force the use of the radar estimate that is collocated with the gauge, By comparing the resulting time series of bias estimates (Fig, 9a) using this new simpler methodology with the corresponding Fig, 6a using the existing methodology, it is clear from this case that the method by which the gauge-radar pairs are determined can have a large impact on the computed biases from the algorithm. The newly computed hourly bias estimates are much lower and more in-line with the storm-total sample bias of 0.614 shown in column four of Table I for a 51 dBZ rain rate threshold. Thus the Adjustment algorithm is successfully detecting the radar overestimation on an hourly time scale that is evident in the storm-total gauge-radar comparisons in Table 1. The performance of the Adjustment algorithm is thus critically dependent upon the gauge-radar rainfall data that is passed into it, and that data is dependent on the method by which the pairs, are formed. By comparing the scatter plots of hourly gauge-radar pairs where the radar estimate chosen is the center bin over top of the gauge (Fig. 10) with Fig. 7, the previous neat alignment of many of the gauge-radar pairs along the I: I diagonal line is replaced with more widely scattered points more typical of what would normally be expected. Figure II summarizes the results from this section by showing the net impact on the gauge-a.djusted storm-total rainfall of changing the method by which the gauge-radar paJlrs are 14