Department of Meteorology Eötvös Loránd University Budapest, Hungary Judit Bartholy, Rita Pongrácz SUBJECTIVE SYNOPTIC CLASSIFICATIONS: HESS-BREZOWSKY „GROSSWETTERLAGEN”, PÉCZELY CLASSIFICATION

HESS-BREZOWSKY „GROSSWETTERLAGEN” Subjective classification from 1952 available daily codes: Coding by: German Met. Service (DWD) 1. Parameters used? SLP, AT Specific program/software available? No and yes Reproducible? No 3. Computer programming skill needed? No and yes 4. Time and computer power? N/A 5. Number of classes? 29+1 – possibly reduced by clustering 6. Key patterns? Subjective definition 7. Distance/similarity measure? No – Euclidean

Coding process of Hess- Brezowsky classification Area of consideration: 00 (COST733) Target area: 07 (COST733) 07

List of Hess- Brezowsky MCP types (29) Dominant flow: 4 zonal 7 mixed 18 meridional C/A dominance: 16 cyclonic 13 anticyclonic

Hess-Brezowsky MCP types Seasonal and annual frequency of cyclonic and anticyclonic patterns DJFMAMJJASONyear Cyclonic60% 53% 57% Anticyclonic40% 47% 43%

PÉCZELY MCP TYPES Subjective classification from 1957 available daily codes: Coding by: György Péczely (Szeged) / Csaba Károssy (Szombathely) 1. Parameters used? SLP 2. Specific program/software available? No and yes Reproducible? No 3. Computer programming skill needed? No and yes 4. Time and computer power? N/A 5. Number of classes? 13 – possibly reduced by clustering 6. Key patterns? Subjective definition 7. Distance/similarity measure? No – Euclidean

Coding process of Péczely classification Area of consideration: 00 (COST733) Target area: Carpathian basin southern 07 and northern 10 (COST733) 07 10

List of Péczely MCP types (13) Dominant flow: 5 zonal 2 central 6 meridional C/A dominance: 6 cyclonic 7 anticyclonic Meridional, northern types (1) Cold front with meridional flow (mCc) (2) Anticyclone over the British Isles (AB) (3) Cold front arising from a Mediterranean cyclone (CMc) Meridional, southern types (4) Warm front arising from a meridional cyclone (mCw) (5) Anticyclone located east of the Carpathian Basin (Ae) (6) Warm front arising from a Mediterranean cyclone (CMw) Zonal, western types (7) Zonal cyclone (zC) (8) Anticyclone located west of the Carpathian Basin (Aw) (9) Anticyclone located south of the Carpathian Basin (As) Zonal, eastern types (10) Anticyclone located north of the Carpathian Basin (An) (11) Anticyclone located over the Scandinavian Peninsula (AF) Central types (12) Anticyclone located over the Carpathian Basin (A) (13) Cyclone located above the Carpathian Basin (C)

Typical sea-level pressure maps of the Péczely MCP types Subjective classification using 13 types Definition: Gy. Péczely Cyclonic (mCc, CMc, mCw, CMw, zC, C) and Anticyclonic (AB, Ae, As, Aw, An, AF, A) dominance is separated (relative frequencies are 34% and 66%, resp.) mCcAB Ae As AwAnAFA CMc CMw mCw zC C 7%, mostly in summer6%, more in summer3%, more in spring 9%, more in spring The annual mean relative frequency is determined using the baseperiod 13%, more in autumn / winter 8%, more in winter / spring 4%, more in winter5%, more in winter 16%, more in summer12%, less in autumn4%, more in summer 11%, more in summer / autumn 2%, more in spring / summer

Péczely MCP types Seasonal and annual frequency of cyclonic and anticyclonic patterns DJFMAMJJASONyear Cyclonic34%41%30% 34% Anticyclonic66%59%70% 66%