General weather situation

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Under weather situations ( GWL ) is understood to weather conditions over a wide area that does not change significantly during a several-day period.

Examples of large-scale weather situations (location of the action centers ) according to Hann Atlas der Meteorologie 1887

Basics

A general weather situation is a certain atmospheric condition, the characteristic flow arrangement of which remains essentially the same for several days (definition according to Baur ). In general, three days are used as the assessment period.

The weather itself can change during a general weather situation, the character of the respective regional weather is retained. The regional formation and the typical sequence of large-scale weather patterns essentially shape the climate of an area. The general weather situation is of great importance for predicting the development of the weather and the weather for a longer period of time.

General weather conditions in Europe

A number of different large-scale weather situations can be distinguished for Europe, and there are different systems.

Low pressure hiking trails to Bebber

General weather conditions after WJ v. Quiver

Wilhelm Jacob van Bebber developed a basic scheme of typical train routes of barometric minima ( low pressure trajectories) as early as the 1890s , which he divided into five groups:

I: from the Atlantic north-east across the northern British Isles to north Scandinavia (Ia), and from there south-east (Ib), east (Ic), or north-east (Id)
II: from the North Atlantic eastwards via central and southern Scandinavia to northeastern Europe
III: from the North Atlantic south-east via southern Scandinavia to central-eastern Europe
IV: from the mid-Atlantic north-east over the southern British Isles and southern Scandinavia (IVa) or north-central Europe (IVb) to north-eastern Europe
V: from the mid-Atlantic south-east over Biscay into the Mediterranean area (Va), and from there north-east (Vb), east (Vc), or south-east (Vd)

From this simple model, which, however, did not define any concrete weather conditions in the course of the individual railways, the designation Vb-Wetterlage has been preserved, the main phase of the north-east trajectory from a Mediterranean low over the Adriatic and Danube region to the Baltic States, the heavy rainfall caused by sliding from the south-east onto the Alps and Carpathian leads.

Large weather typology according to Hess / Brezowsky

In addition to computer-aided processes, the German Weather Service also classifies large-scale weather situations according to Paul Hess and Helmuth Brezowsky - in particular according to the flow situation ( cyclonic or anticyclonal ) and the location of the action centers in the earth's atmosphere and the frontal zone .

Forms of circulation
  • Zonal form of circulation: follows a smooth west-east flow between a deep -reaching subtropical high pressure area in the normal position above the North Atlantic and a deep -reaching low pressure area in the subpolar space - typical examples: western locations
  • Mixed form of circulation: The anticyclonic control centers are shifted northwards to about 50 ° latitude compared to the western locations  - Examples: Southwest locations (control center Eastern Europe), Northwest locations (control center East Atlantic), High Central Europe (as the center), including low Central Europe
  • meridional circulation Form: Stationary, blocking high pressure areas between 50 ° and 65 ° of latitude - Typically: Northern layers, south-facing, easterly and trough layers with a north-south axis direction, northeast and southeast layers
General weather conditions
No. Abbr. E.g.
  A) General weather conditions of the zonal form of circulation
01 West exposure, anticyclonal WA
02 West facing, cyclonic WZ
03 South west facing WS
04th Angular west facing WW
  B) General weather conditions of the mixed form of circulation
05 Southwest exposure, anticyclonal SWA
06th Southwest exposure, cyclonic SWZ
07th Northwest exposure, anticyclonal NWA
08th Northwest facing, cyclonic NWZ
09 High Central Europe HM
10 High pressure bridge (back) Central Europe BM
11 Deep Central Europe TM
  C) General weather conditions of the meridional form of circulation
12 North facing, anticyclonal N / A
13 North facing, cyclonic NZ
15th High Northern Sea - Iceland , anticyclonal HNA
15th High Northern Sea Iceland, cyclonic HNZ
16 High British Isles HB
17th Trough Central Europe TRM
18th Northeast exposure, anticyclonal NEA
19th Northeast, cyclonic NEZ
20th High Fennoscandia , anticyclonal HFA
21st High Fennoscandia, cyclonic HFZ
22nd High Northern Fennoscandia, anticyclonal HNFA
23 High Northern Fennoscandia, cyclonic HNFZ
24 Southeast exposure, anticyclonal SEA
25th Southeast exposure, cyclonic SEZ
26th South facing, anticyclonal SA
27 South facing, cyclonic SZ
28 Deep British Isles TB
29 Trough Western Europe TRW
  crossing U

Objective weather situation classification for Germany (DWD)

The German Weather Service has developed a model based on three measurement criteria that includes 40 weather situations for Germany and the surrounding area. Large-scale direction of flow (5 values: undefined, northeast, southeast, southwest, northwest), cyclonality or anticyclonality of the ground-level and mid-tropospheric currents (1000/550 hPa; 4 values) as well as the moisture content of the atmosphere (2 values: dry, moist ) combined. An example is then:

Class no. 4: Direction of flow southwest, flow A / A, dry → short code SWAAT

All combinations were classified, including those that occur extremely rarely (only a few times per decade). The five most common weather patterns (1979–1990) are:

Class no. Short identifier Frequency (in%)
1 1 XXAAT 9.4
2 15th NWAZT 8.8
3 9 SWAAF 8.7
4th 5 NWAAT 8.3
5 10 NWAAF 7.5

Austrian Weather Pattern Scheme (ZAMG)

Since Austrian meteorology has to take into account not only the Atlantic climate but also the Pannonian and Mediterranean climates with the subtype of the Illyrian climate , as well as action centers from the Sahara to the Black Sea region (which are not taken into account according to Hess / Brezowsky), the Central Institute for Meteorology uses and geodynamics in Vienna the following scheme:

weather condition Abbr. E.g.
High above Western and Central Europe H
Intermediate high H
Zonal high pressure bridge Hz
High with core above Fennoscandia HF
High with core above Eastern Europe HE
North facing N
Northwest facing NW
West facing W.
Southwest facing SW
South facing S.
Gradient weak location G
Deep south of the Alps TS
Deep above the western Mediterranean TwM
Deep in the southwest of Europe TSW
Deep in the British Isles TB
Meridional low pressure channel TR
Continental low Tk
Deep on the Adriatic - Poland train route Vb

literature

  • F.-W. Barley sheaf , PC Werner, U. Rügen (collaborators) : Catalog of the major weather conditions in Europe (1881–1998). After Paul Hess and Helmuth Brezowsky . 5th edition. Potsdam / Offenbach a. M. 1999 ( dwd.de [PDF; 3.9 MB ]).

Web links

Wiktionary: General weather situation  - explanations of meanings, word origins, synonyms, translations

proof

  1. ↑ The general weather conditions in Europe - characterization and hazard potential. unwetter.de, accessed on December 3, 2008 .
  2. ↑ a b Examples: Analyzes. DWD, on the website of the Institute for Meteorology, FU Berlin (met.fu-berlin.de).
  3. ↑ a b Analysis 20030112
  4. ↑ a b Analysis 20030101
  5. ↑ a b Analysis 20030228
  6. ↑ a b Analysis 20030426
  7. ↑ a b Analysis 20030706
  8. ↑ a b Analysis 20030501
  9. ↑ a b Analysis 20030527
  10. ↑ a b Analysis 20030722
  11. ↑ a b Analysis 20030410
  12. ↑ a b Analysis 20030824
  13. ↑ a b Analysis 20030421
  14. ↑ a b Analysis 20030105
  15. ↑ a b Analysis 20031229
  16. ↑ a b Analysis 20030214
  17. ↑ a b Analysis 20051015
  18. ↑ a b Analysis 20031013
  19. ↑ Analysis 20050819
  20. ↑ a b Analysis 20030412
  21. ↑ a b Analysis 20030819
  22. ↑ a b Analysis 20030222
  23. ↑ a b c Analysis 20030121
  24. ↑ The objective weather situation classification; and description of the procedure and the weather condition classes;
    Ernst Dittmann u. a. (S. Barth, G. Müller-Westermeier, J. Lang): Objective weather situation classification. Series of reports from the German Weather Service 197, Offenbach am Main 1995 (pdf);
    Objective weather situation classification. (In: Wettwetterlexikon. )
    All: Deutscher Wetterdienst, dwd.de (accessed May 30, 2016).
  25. ↑ Classification area. dwd.de
  26. ↑ Dittmann et al. a .: Objective weather situation classification. 1991, Table 2: Numbering, definition and short code of the weather situation classes, p. 27; The same. Key figures and identifiers of the 40 objective weather situations , dwd.de.
  27. ↑ Dittmann 1991, p. 7.
  28. ↑ Dittmann 1991, 5.1 Weather Calendar, p. 17 ff, especially p. 19.
  29. ↑ Analysis 20030901
  30. ↑ Analysis 20030711
  31. ↑ Analysis 20031015
  32. ↑ Analysis 20031022
  33. ↑ Analysis 20031002
  34. ↑ Analysis 20031020
  35. ↑ Analysis 20030731
  36. ↑ Analysis 20030215
  37. ↑ Analysis 20050822 ( Alpine floods 2005 )
  38. ↑ Project (ex cost733.org) finished, see cost733.met.no ; accessed May 30, 2016; Final reports on ESSEM COST Action 733 , European Cooperation in Science and Technology, cost.eu.