World Gliding Championships - Leszno, Poland 2003 & PreWorld 2002

Untitled Document

Leszno 2003

Andrew DAVIS
GREAT BRITAIN
Discus 2a - 80
10421 pts;

John COUTTS
NEW ZEALAND
ASW 27b - 47
10347 pts;

Wolfgang JANOWITSCH
AUSTRIA
Ventus 2cx - WO
10594 pts;

Holger KAROW
GERMANY
Nimbus 4M - 1X
11323 pts;

all results >>

FAI International Pilots Ranking List

MAKE THIS YOUR HOMEPAGE >>

Welcome to the weather site!

My name is Jan Młynarczyk and I'll have the honour of being the Chief Meteorologist of the 28th World Gliding Championships 2003 in Leszno.

The aim of this site is to characterise the weather patterns from July to August in Poland. I'll do my best to present as complete a picture as possible both for the competitors and the team members.

Poland has a moderate climate and the end of July/ beginning of August is one of the most favourable periods for long-distance glider flights.
Below I'm presenting a few typical weather situations, together with a description of the atmospheric conditions course.

High pressure system with the centre over Finland - most favourable pressure pattern

The most favourable pressure pattern from the gliding point of view is a high pressure system with the centre over Finland, with the north-eastern inflow of cold and moderately humid air mass. This system can shape the weather conditions in western Poland even for 3-5 days, making 1000km flights possible.

The pressure system presented above is also characterised by:
ˇ long lasting thermal conditions, beginning at 9:00, ending at 18:30-19:30
ˇ clouds: 3-5/8 Cu
ˇ cloud base: 800-1200m in the beginning, going up to h=1800-2200m
ˇ average lift: 3-4m/s, max. over 5m/s
ˇ ground wind: 090-100 3-6m/s
ˇ max. temperature: 20-25 degrees C
ˇ min. temperature at night: 8-12 degrees C

Active low pressure system with the centre over the North Sea

This system is shapes the inflow of cold and humid air mass from the west. The coming air is very unstable. After the passing through of the main cold front, there are subsequent areas of secondary cold fronts with showers areas passing from the west. Nevertheless in such a situation it is possible to fly tasks in the good weather "windows". Such a system can last 2-5 days.

The conditions in the good weather "windows" are characterised by:
ˇ clouds: 4-6/8 Cu, periodically 0-1/8 Cu and 5-7/8 Sc cugen
ˇ cloud base: 800-1400m
ˇ average lift: 1,5-2,5m/s max. 3,5m/s
ˇ wind: 260-300 6-9m/s QNT=10-15m/s
ˇ max. temperature: 18-21 degrees C
ˇ min. temperature at night: 7-10 degrees C
ˇ periodical showers

Ridge of high pressure associated with the high pressure system with the centre over the Azores.

Such a system causes the inflow of cold and humid air mass from NW and can shape the weather for 2-5 days.

The weather can be characterised by:
ˇ clouds: 1-4/8 Cu, locally 1-2/8 Sc cugen
ˇ cloud base: h=800-1200m, going up to h=1600-2000m
ˇ average lift: 2-3m/s max. appr. 4m/s
ˇ max. temperature: 22-26 degrees C
ˇ min. temperature at night: 8-12 degrees C

High pressure system with the centre over Russia

This system causes the inflow of dry and warm air mass from the depths of the continent. This situation happens especially in August and can last for 3-7 days.

This system can have two a little bit different manifestations, depending on the characteristics of the inflowing air mass.

Type 1
ˇ thermal conditions from 10.00-11.00 till about 16.00-17.00
ˇ clouds: blue with isolated Cu fra
ˇ top of thermals: h=600-800m, going up to h=1200-1600m
ˇ average lift: 1,5-2m/s max. 3m/s
ˇ max. temperature: 27-30 degrees C
ˇ min. temperature at night: 12-14 degrees C

Type 2
ˇ thermal conditions from about 11.00-12.00 till about 16.00-16.30
ˇ clouds: blue, locally with isolated Cu fra
ˇ top of thermals: h=600-800m, going up to h=2200-2800m
ˇ average lift: 2-3m/s max. 5m/s
ˇ max. temperature: 27-30 degrees C
ˇ min. temperature at night: 12-14 degrees C

High pressure system with the cetre over Ukraine

This system is characterised by the influence of the high with the centre over Ukraine, causing the southern inflow of warm and dry air mass. This situation mainly happens in August and usually lasts 3-6 days.

This system is usually characterised by the following course f weather conditions:

ˇ thermal conditions from 11.00-12.00 till 16.00-17.00
ˇ clouds: blue with isolated Cu fra
ˇ top of thermals: h=500-700m, going up to h=900-1300m
ˇ average lift: 1-1,5m/s max. 2,5m/s
ˇ max. temperature: 29-34 degrees C
ˇ min. temperature at night: 18-20 degrees C

The above description is only an approximation of the meteorological conditions occuring in the most typical pressure systems. However, the real picture of the conditions depends not only on the pressure and frontal patterns, but above all on the vertical temperature profile and dew point temperature. This is why each synoptic situation requires individual elaboration, whose effect will be a forecast of the real weather conditions, whose parameters might often differ from the ones described above. This is why a detailed and complex analysis of each synoptic situation is necessary, including the analysis of surface maps, upper air maps and aerological diagrams. Its aim is to get a precise weather forecast allowing to make a decision on the tasks to be flown.

Jan Młynarczyk