mean daily NMC Reanalysis (1948)
X axis: whole world in 144 2.50° steps, first point at 0.00° E, last point at 357.50° E
Y axis: regular grid with 73 -2.50° steps, first point at 90.00° N, last point at 90.00° S
Z at 500.00 millibar air_pressure
1-daily data available from 01Jan1948 to 08Oct2018 ( 25902 times)
Variable hgt (mean Daily Geopotential height) in m
Full metadata.

Get grid points, average area or generate subset

Mask:	no mask mask46.txt mask7.txt   add a mask to the list
Latitude:	°N - °N
Longitude:	°E - °E
Boundaries:	halfway grid points interpolated
Make:	average max min set of grid points subset of the field
Demand at least:	% valid points in this region

Create a field with lower time resolution

New time scale:	annual (Jul-Jun) annual (Jan-Dec) seasonal monthly 10-daily 5-daily
New variable:	mean sd sum sum above sum below number min time of min max time of max first time last time of 500mb height
Threshold:	no cut less than greater than m percentile normal 1971-2000
Minimum:	% valid data
First apply:	-day running mean
Missing data:	ignore, climatology, trend, persistence.

Create a field with lower spatial resolution

Average over blocks of longitude and latitude grid cells

Construct a statistical forecast model from this field

Please consider downloading this field from the authoritative site.
If you really want to get it here, NCEP/NCAR 500mb height is available as a netcdf file (size 251.962 MB).