Abstract: A number of changes were made to the National Meteorological Center global data assimilation system (GDAS) during 1982 and 1983. The most significant of these changes was the replacement of the quasi-univariate, sigma-coordinate ...

Abstract: A comprehensive hydrostatic quality control (CHQC) procedure for rawinsonde heights and temperatures was implemented into operational use at the National Meteorological Center (NMC) in December 1988. The CHQC uses a ...

Abstract: Results of a thorough study of the correlation structure of observation-minus-forecast increments for mandatory pressure level radiosonde observations of zonal and meridional wind components and geopotential, differenced ...