The Final (FNL) global tropospheric analyses archived here were
produced by NCEP's Global Forecast System (GFS), which was run
operationally at 12-hour intervals to make multiple-day weather
forecasts, from April 1997 through June 2007. FNLs are analyses that
are produced after the model has completed the forecast cycle, and
they include the most complete set of observations available for a
given cycle. The FNL from a given cycle, which is the best available
analysis, is then used in the initialization of the next cycle.
FNL Data are available on pairs of 2.5-degree hemispheric grids
(North and South) at the Earth's surface, sixteen vertical levels
from 1000 millibars up to 10 millibars, the tropopause, boundary
layer, two subsurface levels, and a few others. Parameters include
surface pressure, sea level pressure, geopotential height,
temperature, sea surface temperature, potential temperature,
relative humidity, snow depth (weekly, Northern Hemisphere only)
precipitable water, u- and v- winds, and vertical motion.