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