18th FAI European Championships Weather Forecast 15th Aug

 

follow up for Aug 14th

• The frontal zone passed through our area but the phenomena did not pass through the Pelagonia Valley.
• However, we had storms all around us, such as to the West, South and East of us, which were in progress at the time we landed, as predicted. Luckily they did not enter our territory.
• As we said in the Briefing, the valley we are flying in, is particularly protected and very dry, as a result of which the ground does not supply the clouds with moisture. 
• On the contrary the west and south valleys are green with high humidity and work first in unstable conditions.
• The usual inversion at 2000m traps a dry air from below that is not easily replaced, and every day part of this moisture leaves with the clouds.
• These characteristics make Krusevo a fantastic and reliable place to fly, (even if it puts the meteo man in a difficult position sometimes). It is better to make a mistake that develops positively than the opposite!

Summary of the day 15th Aug

• The front passed very close to us but did not touch our area which remains dry
• Post frontal, we expect high barometric pressure conditions.
• Blue sky, 
• lower temperature and 
• fewer clouds.
• The air density increases and the thermals will be more "powerful"
• The inversion becomes more difficult to penetrate  
• There will be Cumulus on the horizon over mountains.
• Cu above the valley are not expected or will be rare. 
• Thermals +1m stronger than yesterday, and are expected to reach 2200m which will be the maximum height of the inversion, but the saturation level will be at 3,300.
• If some thermals overcome the inversion, they will accelerate from the colder air and it is possible to reach condensation level at 3300m. However, most thermals are expected to have difficulty rising above 2200m.
• Winds low northeast 12kph and high north 20kph, giving the known convergences of the area, i.e. in the center of the plain and from Prilep to Bitola.

Evangelos

More Details:

Barometric pressure: stable at 1016mb

Temperatures: 18-27 C   lower temperatures

Dewpoint: 6 C dropping 4 C

Humidity at low level: drops to 30% making conditions less smooth 

Humidity Boundary layer: drops from 65%+ to <50% (Dry, cold and heavy upper air)

Cloud base: Theoretically at 3.300m, possible to the west

Cloud tops: +400m

Cloud types:  Cu, Cu congestus, Cu with spreadout, Cirrus and Cb after 14.00 layers from west to east 

Cloud Coverage: Krusevo 80% at 14.00, North valley at 20%but later 70%

Inversion levels: 1850m later 2200m

Energy flow:  better than yesterday, especially in the East valley-more sun

Average Thermal expected +3m/s  

Thermal tops: below 2200m, some may reach 3300m after 15.00h

Thermals at Altitude: +3m/s at 1000m, +3,7m/s at 1500m , +3,2m/s at 2000m     

Ideal Thermal Zone:   1500-2000m

WINDS at 15:00

Wind Gust at Surface: 25 kph valley and 30 kph take off. Calm gusts after 12.30h

0m:  ENE 12 kph less than yesterday

600m:  ENE 12 kph

1200m:  ENE 13 kph

1800m: NE 12 kph  

2400m N 20 kph   

3000m N 15 kph  

3600m: N 15 kph

Conditions start Organizing: 11.00  (up to 1900m) earlier than yesterday-more sun

Conditions decline after: 17:00   (up to 2200m)

Conditions Best Period: 13:00-17:00h   

Conditions Peak time: at 14.30h 

Duration of Conditions:  3 h

Calculated XC Speed:  40-45 kph  

Expected Task Distance   100km

Convergence lines: Prilep to Bitola and Valley center

Rain Forecast: N/S

                                                                      Skew-T at 14.00h