Abstract : 1C.11
Classification of Cyclone Tracks over Apennines and Adriatic Sea

Kristian Horvath, Yuh-Lang Lin, Branka IvančAn-Picek
Meteorological and Hydrological Service

The goal of this paper is to present a subjective mesoclimatology of the cyclonic activity in the Adriatic region. The work is based on the four year (2002 2005) operational ECMWF T511 dataset The main idea of the study is to determine the track types of the cyclones appearing in the region as well as to isolate the mesocyclogenetic areas in the Adriatic area. Cyclonic activity in the Adriatic and Central Mediterranean provide a trigger mechanism for a range of extreme weather phenomena like local downslope wind-storms Bora, strong SE Jugo winds, orographic precipitation, thunderstorms, supercells and mesoscale convective systems. Due to the strong weather impacts, a basic understanding of the cyclogenesis over the Adriatic Sea is essential. In particular, the classification of different types of cyclogenesis in the area is essential since it will help the understanding and prediction of the relevant weather phenomena.

Our preliminary results indicate that four types of cyclogenesis over the Adriatic Sea have been identified: (1) Type A: cyclones developed in situ over the Adriatic Sea without any connections with other pre-existing cyclones in the surrounding areas; (2) Type B: cyclones are connected with other pre-existing cyclones in the surrounding areas. Two subcategories are found: (I) continuous track: cyclones crossing over the Apennines to the Adriatic Sea and (II) discontinuous track: a parent cyclone generated in the Gulf of Genoa (Genoa cyclones) is blocked by the Apennines and a new surface cyclone is regenerated over the Adriatic Sea; (3) Type AB: mixed type A and type B cyclones. In this type of cyclones, two cyclones co-exist on both the upstream (west) and downstream (east) sides of the Apennines (twin or eyeglasses cyclones); and (4) Type C: cyclones coming from Mediterranean Sea, but not from the Gulf of Genoa (non-Genoa cyclones).