Short Introduction ZAMG, WLKC733 Thomas Krennert, ZAMG – Vienna, Synoptic Department email:...

Short IntroductionShort IntroductionZAMG, WLKC733 ZAMG, WLKC733

Thomas Krennert, ZAMG – Vienna, Synoptic Department

email: [email protected]

Thomas Krennert, ZAMG – Vienna, Austria, Synoptic Department COST 733 WG2 Meeting Augsburg, March 2008

ZAMG / SYN subjective


Start: ~1954 with Baur / Lauscher Usable records from ~1959 1957 - 1959 reconstructed Individual knowledge of forecaster

included: mixture of methods continued

Baur Lauscher Hess-Brezowski Schuepp Steinacker

More than 80 classes found Reduced to 43 / digitalized (-) Still identical classes (-) Only regards small domain (+) Largest catalogue of air mass

analysis and frontal passages


Classification: 43 Types

Air mass analysis: upper level (< 850 hPa), surface level (> 850 hPa)

Change of air mass: 2 levels during the day

Frontal passage: type and time of passage over Vienna / Austria.

Air mass analysis and frontal passages are missing for the years:

1957 - 1960

1968 - 1970

1976

1982


Subjective Weather Type Classification ZAMG / SYN-OP

Type Type Effect over

Eastern Alpine Region

Quantity

N / NE / E / SE / S / SW / W / NW

Flow regime cyclonic / anticyclonic

16

HM High pressure centre, Central Europe 1 HE High pressure centre, to the East C / A 2 HB High pressure centre, Great Britain C / A 2 HN High pressure centre, North Sea C / A 2 HF High pressure centre, Fennoscandia C / A 2 HBM High pressure ridge, Central Europe (Axis) 1 HNF High pressure field, North Sea and

Fennoscandia C / A 2

h Intermediate High 1 HR High pressure field, Boundary 1 f Weak pressure gradient C / A 2 TM Low pressure centre, Central Europe 1 TIW Low pressure centre, to the West 1 TWM Low pressure centre, Western

Mediterranean

TS Low pressure centre, to the South 1 TB Low pressure centre, Great Britain C / A 2 TRM Trough, Central Europe 1 TRW Trough, Western Europe C / A 2 HT Upper level low 1 UGL Changing Weather Type C / A 2 ===== 43

Air mass analysis ZAMG / SYN-OP Cold air masses Air mass (ZAMG) Naming Origin Properties

cPA (caK) Polar air from

Northern Siberia Northern Siberia (from NE, over Russia)

Extremely cold, dry

mPA (maK) Arctic Polar air Arctic (From N over Northern Sea) Very cold, moist cP (cGAK) Russian Polar air Eastern Europe (from NE / E over

Eastern Europe) Cold, dry

mP (mGAK) Polar air from Greenland

Arctic (from N, NW over Greenland Sea)

Moderately cold or cool, moist

cPT (cGAW) Old, returning Polar air

Arctic (from E, SE over South Eastern Europe)

Moderately cold, dry

mPT (mGAW) Warmed Polar air Arctic (from NW over Northern Europe)

Cool, moist

Warm air mass Air mass (ZAMG) Naming Origin Properties

cTP (cGTK) Continental Central Europe, South Eastern

Europe Dry, warm during summer, moderately cold during Winter

mTP (mGTK) Sea Air Northern Atlantic (from NW over British Isles)

Moist, mild or moderately warm

cT (cGTW) Continental tropic air Near East (from SE over Balkan peninsula)

Hot, dry

mT (mGTW) Atlantic tropic air During High over Azores (from SW over Iberian peninsula)

Moist, warm

cTS (cTW) African tropic air Sahara (from SE over Balkan peninsula)

Dry, hot

mTS (mTW) Mediterranean tropic air

North Africa (from S, SW over the Mediterranean)

Muggy, hot, hazy

Two layers: upper level (mostly < 850 hPa) / lower level (mostly > 850 hPa)

Fronts ZAMG / SYN-OP Decision tree: yes/no, type, passage over Vienna (UTC) Surface fronts: Cold / Warm / Occlusion Upper fronts: Cold / Warm, only in combination with significant surface weather Upper level trough Convergence line Thickness Ridge with rain or thunderstorms Baroclinic Boundary Masked Coldfront Comma


WLKC733


Flow pattern direction including indication of cyclonicity and precipitable water

Each parameter could be investigated seperately (alphanumeric output)

More equally distributed on smaller domains

Applicable only for small domains

Easily applicable operationally

Advantage within areas with orography


Method:

First two letters denote main wind sector number counting clockwise: sector 01=NE, 02=SE, 03=SW, 04=NW, 00=undefined (varying directions)

Wind direction at 700 hPa indicates flow Derived from u-, v- components of true wind 2/3 of all weighted wind directions have to be connected to a sector of 10° Sector is assigned to a quadrant (i.e. „SW“ = [190°, 280°])

Third letter denotes >A<nticyclonicity or >C<yclonicity at z925. 4th letter denotes >A<nticyclonicity or >C<yclonicity at z500.

For each grid point Weighted area mean value is calculated [gpdm2/km2 * 10.000]

5th letter denotes >D<ry or >W<et.

Weighted area mean value of precipitable water (whole atmosphere) Compared to area daily mean value (annual variation) Indicating values above or below of daily mean

)(2


1) parameters: z925,z500,u700,v700,pw

2) software: code available on cost733 - wiki

3) background: basic knowledge

4) time/CPU: few seconds

5) number of types: 40, could be reduced

7) key-patterns: subjective / thresholds

8) distance measure: thresholds

Profile WLKC733Profile WLKC733


6) literature:

Dittmann, E., 1995: Objektive Wetterlagenklassifikation, Offenbach am Main, Selbstverlag des Deutschen Wetterdienstes, Berichte des Deutschen Wetterdienstes, Band 197.

Bissolli, P., 1999: Kommen Westwetterlagen häufiger vor als früher? Klimastatusbericht 1999, 26-30, Deutscher Wetterdienst, Offenbach a.M.

Bissolli, P., Dittmann, E., 2001: The objective weather type classification of the German Weather Service and its possibilities of application to environmental and meteorological investigations, Meteorologische Zeitschrift, Volume 10, Number 4, 1 July 2001 , pp. 253-260(8)


Adaptations:

Subjective weighting (after “experiments”) Small central domain with dominant weighting

15X

2X1X

Short Introduction ZAMG, WLKC733 Thomas Krennert, ZAMG – Vienna, Synoptic Department email:...

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