Comparison of NMC analysis model winds and temperatures with aircraft measurements

Case study comparisons between in situ aircraft observations of wind and temperature data and National Meteorological Center analysis fields are presented. The aircraft route, from Bahrain near the Persian Gulf to New York, lies approximately half over the data-rich area of Europe and the Middle East and half over the datapoor area of the North Atlantic. The average difference in the wind speed is found to be almost 12 m/s. Surprisingly, the wind differences are sometimes as large over the land area as over the ocean.