High resolution isentropic model applied to local weather forecasting

Abstract

To our dear friend, mr. sc. Dražen Glasnović who was an exceptional research scientist. He left too soon taking his great ideas with him. Nevertheless, his priceless work will keep us going and he will never be forgotten.

This paper is primarily devoted to general discussion of HRID (High resolution isentropic diagnosis) model developed by Glasnović (1983) and its vertical time cross-sections used operationally on direct output of forecasting model ALADIN (Aire Limitee Adaptation Dynamique et Development International). HRID is based on polynomial hydrostatic adjustment technique making use of reciprocal value of thermal stability parameter and its higher order derivatives. Since these relations are applied in local points of vertical interpolation, the problem is considered analytically, eliminating the finite difference approximation procedure in layers with different isentropic thicknesses. This paper presents a local 72 hourly ALADIN/HRID forecast for the city of Split, Croatia, at the eastern Adriatic coast, with detailed vertical atmospheric structure indicating the characteristic features of a frontal passage on 2 January 2007.