Ensemble Statistics Files

Not all information is in the ensemble mean.  However, downloading
the 80 ensemble members could be too difficult.  So some ensemble
statastics were calculated using the -ens_processing option of wgrib2
using sub-option "1".

1) ensemble mean,  em = sum(x(i))/n,  i=1..n
2) ensemble spread, RMSE = sqrt(sum((x(i)-em)**2)/n)  note: n is used rather than n-1
3) minimum = minimum value over all ensemble members (for each grid point)
4) maximum = maximum value over all ensemble members (for each grid point)
5) 10 percentile
6) 25 percentile
7) 50 percentile (median)
8) 75 percentile
9) 90 percentile

For certain variables

10) probability of precipitation > 0 *
11) probability of more than a trace of precipitation (trace=TBD) *
12) probability of 2m temperature greater than 273.15K *
13) 95 percentile for WIND at 10m above ground *

* optional, the definition of trace of precipitation is ad hoc
     trace can mean precipitation that will get the rain gauge wet but register as zero
     trace can mean less than 0.01 inches
     trace can mean less than 0.1 mm
     for wgrib2, trace = accumulated precip < 0.xxx mm, or a rate < 0.xxx mm/day.

https://www.cpc.ncep.noaa.gov/products/wesley/wgrib2/ens_processing.html
The above URL shows how the percentiles were calculated.  It also shows
how to display the fields using GrADS.