Understanding RASP Upper Air Soundings/SkewT
The NZHGPA funds 50% of the costs of the NZ RASP website: http://rasp.nz. This is a regular series explaining how to interpret and use the different forecasts that are available.
A
bility to read Upper Air Soundings or SkewT-LogP’s should be a skill every pilot should understand and is used by the majority of top pilots. It’s a one stop shop for understanding many different factors such as temperature, dew point and winds with altitude. This information can be used to evaluate stability, cloudbase, top of cloud, wind profile, and many other atmospheric features. There are five principal quantities indicated by constant value lines: pressure, temperature, potential temperature (θ), saturation mixing ratio, and equivalent potential temperature (θe) for saturated air. There are lots of resources on the internet to help fully understand these charts, but even if this is all Greek to you these charts can still be very useful for you - if the chart has hour glass shape like the one in the image below, then this will tell you that there will be good thermals!
Part 4 By Sven Ericksen
https://ayvri.com/scene/31jnx23r5d/ ckjzk5w8o00013h6gw49e16nd Plan for the day
In practice on this particular day there was over 20-25 km of headwind near turnpoint one and two. Note the black dots on the thermal updraft picture. This indicates wind that is likely to shear the thermals and make it potentially difficult for flying paragliders.
Other flights on 15 January 2021: https://bit.ly/32w60Yd w w w. x c o n t e s t . o r g / 2 0 2 0 / n e w z e a l a n d / flights/daily-score-pg/#filter[date] 21-01-15@ filter[country]=NZ@filter[date] 21-01-15@ filter[country]=NZ To see the relevant pages online visit: https:// tinyurl.com/RASParticles.
Interview with Sebastien Kayrouz
The Upper Air Sounding forecast displayed above is for 2pm on 15 January 2021. On this day Louis Tapper did a 172 km FAI triangle in Central Otago. It was not an especially good forecast according to Louis, due to wind at 2 of the corners of the triangle. Note the inversion of 10,000ft and light wind for the sounding. On a perfect day the blue line (dew point) would almost be touching the red line (temperature) often indicating cumulus cloud. On this particular day the sky was relatively blue with minimal cumulus.
Louis Tapper’s triangle on 15 January 2021
To see the relevant pages online visit: https:// tinyurl.com/RASParticles.
FS Scoring Update Just released is FS 2021 R1.0, which introduces GAP 2021: · Fix error in time points reduction formula in stopped tasks with multiple start gates · Start the Leading Coefficient graph used for leading points calculation at task start time · Improve leading points calculation for pilots landing out and fixes a number of bugs in points calculation as well as result reporting. Link http://fs.fai.org/trac/wiki/FS2021R1.0 -Elena Filonova, CIVL Administrator & Competition Coordinator,
16 A i r b o r n
Links for reference Image 1: rasp forecast for the day https://bit.ly/3x7Dj1R http://rasp.nz/rasp/view.php?region=NZSOUT H_S&mod=+0&date 210115&all=sounding8&sec tion=NZSOUTH_S.sounding.params Flights on 15 January 2021: Image 2: https://bit.ly/2Q6F7Y3 www.xcontest.org/2020/newzealand/flights/ detail: yakernz/14.01.2021/23: 15 3d track https://bit.ly/3slwshz
Continued from page 14 The trickiest part was forecasting the weather conditions and identifying the best day to make the attempt. Above; Sebastien’s Tell us about those fiancé provided who supported you logistics support on the way (friends, NAC, trainer, local pilots etc) It is a long preparation process so I leaned on many people. My flying friends and our local club (the Buffalo Mountain Flyers) gave me excellent support. Tell us how it was to break the record. What was the most difficult? Decisive? Unexpected? The most difficult part of the day was the first 1.5 hours of the flight over the Texas Hill Country. That section is a dense forest without any landing options so there was no margin for error. I had to cross it in the morning when the lift was still weak. A decisive moment came halfway through the flight when I got low and was not hitting any lift. A group of turkey vultures started thermalling at a distance and pointed out the lift. They helped me get back to altitude and had it not been for their helping hand my flight would have ended there. The unexpected was the number of birds I encountered. There were far more than what I have encountered on previous flights. I believe they hunt for good convergence lines too. Any advice to pilots, interesting notes, shared experience that you gained while breaking this record? Record flying is all about preparation and intimately learning the terrain and its micrometeorology. Texas is at the intersection of many weather systems so conditions here are not consistent and almost no 2 days are alike. Good mental disposition and physical endurance are also very important.
