On the merits of the "tendency method" for the spectral and LFM II sea level pressure forecasts

"For many years the sea level pressure forecasts from the 7L PE model (and the LFM model) have been computed by the "tendency method". This piece of jargon means that the sea level pressure forecast is formed by adding to the initial analysis of sea level pressure the change in pressure forecast by the model. This is in contrast to the forecasts for all other levels in the atmosphere which are computed by various forms of interpolation directly from the sigma-layer quantities forecast by the model, without reference to the initial analyses. An earlier study (unpublished) of the late 7L PE model indicated that use of the tendency method did help, thus prompting this study of the effects of the tendency method on the spectral and LFM-II models"--First page. John D. Stackpole, Charles L. Vlcek. "July 1981." "This is an unreviewed manuscript, primarily intended for informal exchange of information among NMC staff members." Includes bibliographical references. 1981 NWS (National Weather Service) Library Public Domain 1931