Objective Determination of Heat Wave Patterns

A simple index was developed in order to objectively characterize a heat wave pattern in either analyses or forecasts of 500 mb height. 500 mb height was chosen because this parameter is usually among the most accurate fields predicted by numerical models. In addition, it is highly correlated with the surface air temperature on many time scales. The heat index IN is designed to be applied to any region of interest and to be used for any objectively analyzed data and specifically those of NWP models.