Abstract
Root-mean-square errors of the 24 h operational, objective, maximum-minimum temperature forecasts derived from primitive equation model predictions and model output statistics are evaluated in terms of synoptic-scale and mesoscale contributions. Eight regions of the United States are examined for the period from December 1974 through November 1976. Climatology and persistence are used for comparison. For the operational forecasts, the synoptic-scale and mesoscale contribute approximately equally to the error. On the synoptic scale, the objective predictions are significantly more accurate than persistence and climatology. However, on the mesoscale, the predictions have approximately the same accuracy as climatology for minimum temperatures and only slightly more accuracy than climatology for maximum temperatures.