This work was funded by a grant/cooperative agreement from the National Oceanic and Atmospheric Administration (NA050AR4311004 and NA10OAR4310210). The views expressed are those of the authors and do not necessarily reflect the views of NOAA or its subagencies.
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Specifically, a Gaussian fit is made to the tercile probabilities, and this probability density function is used to determine the probabilities for the 15% tails.
For the five final months beginning in October 2009, CMAP data were unavailable, and Climate Anomaly Monitoring System–OLR Precipitation Index (CAMS–OPI) rainfall data (Janowiak and Xie 1999) were used instead.
The change in observed relative frequency from the climatology forecast category to the first forecast enhancement level is most critical in assessing forecast confidence, because the forecast categories of greater enhancement level were forecast much less frequently for both precipitation and temperature (Table 1).