A short range ensemble forecast experiment on jet streaks to improve forecasters' model diagnoses, 2004--2006.

摘要

A direct relationship exists between upper level jet streaks and surface cyclone evolution. The goal of this study was to the validate application of subjectively held theories by operational meteorologists regarding this relationship. Specifically, forecasters subjectively favor a deeper/weaker and less/more progressive solution to model surface cyclone forecasts when a model under/over initializes jet level (∼250 mb) winds respectively. In this study application of upper level jet theory combined with National Oceanographic and Atmospheric Administration, National Weather Service, and the National Centers for Environmental Prediction, Short Range Ensemble output was used to partially validate the forecasters approach. Although a limited number of suitable cases were identified where initialized jet streaks played a key role in surface cyclone evolution, the results generally supported the practices invoked by operational meteorologists. Further, the study revealed the location of the over/under initialization relative to the jet streak was a critical factor in determining how to conceptually modify the model forecast of surface pattern evolution.