Table 1: The 14 most frequent (out of total 19) synoptic classes according to Alpert et al. 2004, Osetinsky 2006.

Group Class Acronym
RST Red sea trough to the east RSTE
Red sea trough center RSTC
PT Persian trough weak PT-W
Persian trough medium PT-M
Persian trough deep PT-D
Highs High to the west HW
High center HC
High to the north HN
High to the east HE
Lows Deep low to the east LE-D
Deep Cyprus low to the north CLN-D
Shallow Cyprus low to the north CLN-S
Cold low to the west LW
Shallow low to the east LE-S