Introduction

Probabilistic forecasts can be presented as percentiles. For example, 10% forecast of temperature means that 1 time out of 10, the expected temperature will less than the forecasted temperature. The -set_percentile option adds or changes the percentile of a forecast.

Percentile forecasts use product definition templates (PDT) of 6 or 10 depending whether the forecast is for a single time or a time interval. The -set_percentile option converts pdt 0..6 -> 6 and 8..15 -> 10.

Percentiles are also supported by the -set_metadata option.

Usage

-set_percentile X         X = percentile 0..100

Example

$ wgrib p.grb -set_percentile 50 -grib_out new.grb
1:0:d=2010020304:PRMSL:mean sea level:6 hour fcst:50% level
2:17960:d=2010020304:PRES:1 hybrid level:3 hour fcst:50% level