Abstract
Comparison between in situ aircraft observations of temperature and National Meteorological Center and Global Weather Central analysis fields of temperature is presented for a continental and oceanic flight route. The standard deviations of the temperature differences over several hundred flights are found to be 2.5 and 3.5°C for the continental and oceanic route, respectively. A bias towards warm temperatures of about 0.85°C for the analysis fields was found for the oceanic route. Only small differences are found between the NMC and GWC analysis field temperatures.