PWC Superfinal Roldanillo Feb 13th Weather Forecast

 

Summary

The forecast of the 12th predicted an average XC speed of 28,6kph. Ospina reached goal with an average of 28,5kph, meaning that in some parameters we were close, e.g. XC Speed, Inversions, Top of lift at 2.100m. However it seems that predicted precipitation clouds were in the Nort East and at Roldanillo due to the Shaddow of the Overdevelopment, the conditions cycle was blocked and clouds had a reset for a second cycle, giving the opportunity for the task to complete. Of course if you were lower than the fist inversion level it would be difficult to save the flight, and it must have been a matter of timing. Thermals may have been less powered and if you were out of the gaggle the game was not easy.

Comparing to the previous day, we expect similar humid conditions with high cloud coverage, and increased CAPE energy, implying a high possibly of precipitation between 14.30 and 15.30. Pacific air with high humidity is approaching from the west, creating low cloud coverage at 100% above the mountains in the west of the take off from the early morning. Initial cloud bases in the west will be at 1200m. The day will start working around 10.30 with light east gusts less that yesterday at the take off (15kph). Ideal take of time will be 13.00. At that time cloud base above high ground will reach 2000 and at 14.30 it is expected to reach 2400 near the mountains and Cu clouds will appear to the east of Roldanillo in the valley to Zarzal. Then overdevelopment is expected with a lot of energy released at cloud base (1.600j/Kg) meaning a fast development of precipitation clouds (85% possibility for rain before 15.00) and 20% thunderstorm probability in the area.

Therefore conditions and cloud base will decline after 15.00 giving a 2h flying window opportunity with an air start at 13.00 and landing at 15.00 and an XC speed of 24kph. This means that the Task can be around 50 -60kph according to the forecasted conditions due to the expected rain.

Live Cloud Radar:

Sat24 image

PWCA

Details:

Barometer at 1010mb increased by 1mb

min temp 20 C

Max temp 27 C

DT =7 C, less than yesterday, predicting weaker thermals than yesterday 

High humidity>100% west of Roldanillo and 77% in the east side of the valley, predicting better conditions for a valley task

Cloud base: Low clouds on the mountains at first (1200m) early in the morning. Then Gradually increase to 2000 with a peak at 2400 around 14.00 and 2100 above the flat lands. After 15.00 it will drop.

Cloud tops are expected to increase first in the west reaching 5.000m 

Cu and CuConj clouds in the area, with overdevelopment half and hour earlier than yesterday (theoretically after 14.30) and possibility for Showers across the region and some isolated thunderstorms with a 20% probability. Due to high cloud layer at 100% the clouds will develop slowly, however after 14.30 we expect a faster energy release and vertical overdevelopment

Inversion levels: a low layer at 1100m like yesterday and a higher layer at 1800m (yesterday 2100m) Another level at 1500m will be there due to cross winds turning to North.

Cloud coverage 100% in the west mountains and 80-90% in the flat lands. 

Thermals around 0,8m/s netto up to 1200m, 1,3m/s up to 1300m and +2,5 neto above 1500m.

Thermals will be weaker above 1800m and will stop climbing at 2000m. Thermals are expected stronger in the east of the valley.

Therefore, the ideal thermal zone between 1500m and 1800m

Thermal Gusts in proximity to the ground are expected at15kph at the day peak (13.30-14.30)

average winds:

Ground East <10kph 

In the whole boundary layer expected <10kph. Lower winds from the east and above 1500m winds from the north. 

Thermal activity starts around 10.00, ideal take off at 13.00 

Day conditions decline after 14.30-15.00

Day peak at 14.00

Potential duration of conditions 2h between 13.00 and 15.00

Potential XC speed 23,6kph a slower day than yesterday

Potential task 50-60 kph

Vangelis Tsoukas